Scientific American 1924-05: Vol 130 Iss 5

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SUNITA IGHTIETH YEAR lM | HASUHUNUTFUAOUUACUERAOHHUTAET HUES ~ a TT al UINUNOHULUAEN ALU UNUHNLLULULAUA UAT Wn THE MONTHLY JOURNAL OF PRACTICAL INFORMATION NEW YORK, MAY, 1924 A nt w Hy vt P odes . J cio A ‘4 [oon : ied . : Ms (THE announcer’s microphone (1) is located in a sound-proof carrier wave is being sent out, the microphones are switched in elevator noises from the main corridor to the studio. The an- announcing booth having double plate glass windows and or studio director or announcer is wanted on the telephone. nouncer, who is the key to the whole situation, is in direct giving clear vision to both studios. Special walls render the Each door to the studios has a red signal light (11) which indi- communication with the engineers through desk telephone (17) booth practically impervious to sounds from the studios. The cates that the studio is on the air. If any one disregards The equipment panels (18) are mounted with all the neces loud speakers (2 and 3) in the studios repeat the announcer’s this signal and opens the door when transmission is taking apparatus for controlling the microphone amplifiers and input introduction of artists and also enable him to give directions place, the loud speakers are automatically disconnected. As a currents to the special cables connecting ‘the studio with th regarding placement of instruments and singers while the studio further precaution the doors (12) are equipped with special broadcasting station as well as controlling and adjusting remot« is idle. Switches on the announcer’s control panel (4) enable knobs which can be opened only by some one familiar with them. control telephone lines which operate the station from outside him to switch in his own announcing microphone or those in A loud speaker (13) concealed in a horn closet, reproduces points. Special equipment for equalizing lines to correct attenu- large and small studio (5, 6 and 7). There are two microphones the broadcast entertainment for the reception room. A _ venti- ation, as well as instruments for measuring the gain of any in each studio, one regular and one emergency. The announcer’s lation system through ducts (14) keeps the studios and recep- amplifier and group of amplifiers, is provided. Behind the loud speaker (8) enables him to hear the performance as heard tion room cool and comfortable under all conditions even though panels is a large loud speaker (19) which provides the moni- by the radio audience so that his directions are given from the all windows are closed. Adjustable deadening curtains (15) are toring engineers with either the studio output or with the audience’s point of view. The signal lights (9 and 10) indicate readily adapted to suit the music being transmitted. A double output of a loop radio receiver. The indir vidual views show by colored lights whether or not the studio is on the air, the wall with dead air space (16) prevents radiation of hall and (1) the studio, (2) aerial, (3) broadcasting, (4) control board. THE RADIO BROADCASTING STUDIO OF 1924: A VISIT TO STATION WEAF IN NEW YORK CITY

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“This Is Station Putting Radio Programs On the Air and Taking 302 | eeere acmunees NE, two, three, four, five. Hello, Fort | SaaS | | ey” \ | Wood, One, two, three, four tive Hello, { | Fort Wood Here's some music for you, | " And moment later came the strains of , i Nee } the Anvil Chorus from the opera Il Trova l ———_8 , nes tore, played fer about the fiftieth time that day by the hardworking cylinder-type phonograph of rather questionabl musical attainments That s the radio broadcusting program of 1909 AS au miuatter ¢ it wus not intended as a hbroudcast feature. Back in those days we firmly believed that radio telephony might be used as a rapid means of wireless communication, especially for military operations Of course we appreciated the fact that the radio tele phone conversation could be intercepted by anyone, but it never occufred to us that this means of communication might be employed for nation-wide entertain- ment Little did we dream that the very weakness of radio telephony—its total lack of secrecy—-would some day become ts greatest asset a With Sputtering Are and Baked Microphone No beautiful broadcasting studio Was available in those pioneer days for our radio telephone efforts. Instead, we were working in the icy-cold room if the wireless station located behind the big disappear- ing guns of Fort Hancock, amid the barren wastes of that stick of land known as Sandy Hook. No neat and ilmost invisible microphone was presented for our vocal talent; instead, we were shouting into a long fiber horn, aS we stood before a large table fitted with a tall back covered with delicate electrical meters and fuses and switches. Immediately before us were ten tall copper cylinders, filled with water, and resembling nothing so much as the pipes of an organ. Below each copper cylinder was a large carbon button, all but inst the bottom of its respective cylinder. pressi ek aea Between the cylinder and the carbon button played un unsteady electric arc, sputtering and flickering all the while. The ten ere units were arranged in two banks of five ares each, each bank controlled by a iarge upright handle, so that all five ares of the bank might be struck at once. Once the ares were formed by touching and then separating the copper and carbon members, it Was necessary to udjust the gap of the are so as to get " (he utmost stability, making for uniform radio waves on which to impress the tele- 1 hone messigce or nusi¢ And here was the annoying feature: for no sooner did we get one of the ires fairly constant nd turned our efforts to the next unruly are, than the first arc would go off ona rampage, electrically speaking. Cliven ¢ xceptional luck. if was possible it times to get all ten ares on their best behavior Chis happy state of affairs was confirmed hy the passive state of one of the electrical instruments known as the ' oscillating circuit) rail The next step was to prepare to talk. i-ummeter. The microphone, or device which trans lates sound waves into their electrical equivalents, was in this case a flat cart ridge with two contact buttons. It was slipped mto a holder over which was placed the long fiber horn. Then, if the arcs were still behaving themselves, we were ready to talk—or shout, to be more precise in our description. All! of which wus for the purpose of LS GORE a eT ia ll A SS EMT ETT S Upper left: Standard super-heterodyne partly open to show the six tubes, tuning condensers and batteries. Lower left: Handsome period cabinet receiver. Right: Cabinet type regenoflex receiver, convincing the United States Army Signal Corps that here was a wireless telephone that would work on occasion. We were endeavoring to put some soundseinto the air at Fort Hancock, and trying to get those same sounds out of the air again at Fort Wood. eighteen miles away as the crow flies. The Fort Wood receiving station was by no means of fortu- nate location, so far as radio is concerned, because it nestled right at the very feet of the bronze lady known as the Statue of Liberty. Despite the applica- By Austin C. Lescarboura, Mem. Three 1924 models of radio receivers. SCIENTIFIC AMERICAN Author of “Radio for Everybody,”’ “Wireless Major E. H. Armstrong, the well-known inventor of present-day radio receiving circuits, and his latest model of super-heterodyne receiver tion of a five-kilowatt input at the transmitter—just ten times as much energy as the usual present-day broadcasting station—we could only hope to. get through to our anxious listeners-in once in a great while. The output from our are transmitter was passed in large measure through the cartridge microphone, with the consequence that the loose carbon grains of the microphone were soon baked into a solid mass by the developed heat. All the while we were speaking or playing the phonograph, it was necessary to rap the microphone holder with a screw-driver so as to break up the baked carbon grains in order that the sound waves could be accurately translated into variations of the outgoing radio waves. At the end of several minutes of more or less uncertain transmission, the microphone would be baked soiid and a new one would be necessary. That, in brief, was the 1909 model of radio broad- casting station. The author, who participated in those early radio telephone attempts, had no illusions about with self-contained loud-speaker the possibilities of radio telephony. To him, as well as to others engaged in that early experimental work, the technical obstacles were such as to seem insur- mountable. As a laboratory experiment, the radio telephone was indeed interesting: but as an everyday convenience, it was doomed to failure. upon as a public institution. Aside from radio amateurs, who are primarily inter- ested in communicating with one another by means of the dot-dash language of the telegraph code, numerous laymen were buying receiving apparatus so as to listen in on these experimental talks and phono- graphic concerts which could be taken out of the air. So radio broadcasting came about, and the rest of the story is of too recent origin to require reiteration at this time. If anything, it is the present-day vacuum * tube which has made radio broadcasting possible. The pioneer workers, making use of the troublesome and uncertain carbon are for generating the radio waves, were hopelessiy handicapped. Not only was the carbon are most inefficient in the generation of radio energy, but such energy as it did produce had to be handled May, 1924 99 Them Out of the Air A.LE.E. Course,” ete. And Along Came the Vacuum Tube In the annals of a young art like wireless communi- cation, fifteen yeurs is an age. Even as we were experimenting with our crude are transmitter, Lee DeForest, a wireless experimenter and inventor already well known at that time, was at work on his audion- a modified form of electric bulb in which are placed two elements in addition to the usual fila ment, one of these a metallic plate or cylinder, known us the “plate,” and » other a lattice-like structure known as the “g : Four years after our d artening efforts at wireless telephoning, a youug student at Colum- bia University, Edwin H. Armstrong, was delving deeply into the intricacies of the audion or vacu- um tube, and evolving new and wonder- fully efficient circuits for radio transmis- sion and reception. That was in 1913. Two years later, the American Telephone & Telegraph Company startled the world by assembling a large battery of vacuum tubes for the purpose of generating radio waves with which the human voice was # projected through space from Arlington to Paris. Then, as if the spanning of the Atlantic were not a sufficient accomplish- ment, the telephone engineers immediately followed up this feat by talking between Arlington and the far-away Pearl Harbor in Hawaii, a distance of 7500 miles. That was in 1915, the same year that the trans-continental telephone line was inaugurated—an astounding engineering achievement also due in large measure to the application of the vacuum tube, this time as a perfect “repeater” to build up attenuated voice currents at intervals on their long journey from coast to coast. From 1915 the story of the radio telephone moves along through the trying days of the World War. With our entrance into the fight, we found it necessary to develop the radio telephone as a means of rapid com- munication between airplanes and the ground. It is safe to say that years of normal radio development were crowded into months in those days of great anxiety. Then came 1921. The Westinghouse organization began a series of radio telephone experiments for the purpose of testing certain microphones and radio telephone trans- mitters. Soon the radio amateurs took keen interest in those experiments. After a while the S Westinghouse organization found that its experiments were coming to be looked more or less directly with a microphone which could not stand up under such an electrical strain. Back in our 1909 ex periments we had to change microphones about every five minutes—and each micro- phone cost us about $3.00! Now the vacuum tube is the marvel of modern electricity. It can be used to convert direct current into alternating current of very high frequencies, suitable for radio transmission. Feed it alternating current of any frequency, and it will convert such current into direct current. It may be used to detect delicate radio waves; in fact, it is a super-sensitive detector in radio work. The vacuum -” Lin at tt

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May, 1924 tube acts as a relay or repeating device, in that it will impress on a powerful current every characteristic of a weak current. It is this facility which permits of using the vacuum tube as an amplifier in radio receiving, or as a so-called modulator in radio trans- mission, when the delicate voice currents are impressed on the powerful transmitting waves, or as the repeater in the long-distance telephone line, when it becomes necessary to boost up the attenuated telephone currents at the end of every so many hundred miles of line. The Gentle Art of Broadcasting How quickly we have become accustomed to broad- casting! Only a few years back we were contented to spend our evenings reading the newspaper, a maga- zine, or a bulky book. If we desired a little entertain- ment, we went to the nearby motion picture house or to the theatre. Or we even called on our friends in order to pass the evening. Today it is quite different. On our way home we look through our newspaper for the radio programs. We learn what is going to be put on the air tonight for our entertainment. Not only do the radio programs tell us the names of the artists and speakers as well aus their offerings, but also the exact time at which we cun look for those very features. Instead of having to go out for our entertainment, we have merely to turn the dials of our to the proper set- tings, and the entertainment from out of the sky. It is now too commonplace to be fully appre- ciated, this wonderful thing called broadcasting. There are two radio broadcasting: first, the talk or the music must be put on the air by means of a radio telephone transmitter; secondly, the talk or radio receiver comes to us sides to the music must be taken out of the air by means of a receiving set. The radio waves which carry the talk or the music are strongest when nearest to their source, and gradually grow weaker as they spread out in ever widening circles to the vast radio audience. The object of the receiving set is to intercept a small por- tion of the desired radio wave in its immediate vicinity, by means of “tuning” or adjusting the frequency of the set to the desired wave, and then convert the energy of that radio wave into a replica of the original The nearer we are to the broadcasting station, the more powerful the waves and therefore the more energy can be inter- Furthermore, the more powerful the _ radio energy that is being handled sounds, radio cepted. by the receiving set, the simpler the apparatus re- quired. All of which may be quite elementary but is quite nec- essary in preparing us for an understanding of the present trend of broadcasting. The latest statistics dis- close that there are in the United States and Canada something like 600 radio 3 broadcasting stations. Of this number, approximately 130 are using 500 watts or These are sufficiently scattered so as to blanket the entire country. At first glance, this would appear to be a_ splendid thing—six hundred broad- casting stations putting as Ry fT, more, stations many programs on the air day after day. Surely, one need never worry” about picking up an enjoyable pro- gram, in view of the variety offered by the combined efforts of the broadcasters. But unfortunately, this is one cases where quantity is of secondary consideration if, in truth, it is not of the very first consideration. With so many high-power stations there is, if receiving condi- e tions are as in the cold, crisp winter evening, a considerable overlapping of wave lengths and, as a re- sult, more or less interference. Hence the listener-in needs a high-grade set in order to pick out any par- ticular station and bring it in so that the quality is good. This is especially true if he is located in the vicinity of one of the undesirable stations. Then. to make the situation worse, the public is bent gor rd SCIENTIFIC AMERICAN upon long-distance reception. Why it is essential that we listen to the impossible program of the Podunk Fire Department's band playing from the Podunk station, when the nearby station is broadcasting Paul White- man’s famous dance provocatives, would be a deep mys- tery except for the fact that Podunk is 2281 miles dis- Simple internals of the Armstrong super-heterodyne receiver. loop which intercepts the radio wave tant. Distance lends enchantment. And there you are. In an effort to obtain distance, in too many cases the listener tries to “get” stations that are beyond the proper capacity of his receiving apparatus, which results in forced regeneration in what is known as the regenerative receiver. Forced regeneration causes Typical multi-tube radio frequency portable set, with self-contained loud- speaker. The loop is in the lid of the case the receiver to act as a miniature transmitter which emits a radio wave of about the same wave length as the station that is being listened to with more or less success. Meanwhile, other listeners-in within a quarter of a mile or more are picking up the emitted wave which now gives rise to a whistle in their head-phones 303 or loud-speaker. This case, multiplied by dozens of others in the case of a small community, or by thou- sands in the case of a lurge city, results in a bedlam of whistles, groans, shrieks and whatnot which break up the radio programs for many of the radio audience Unfortunately, for the past two years our short-sighted radio N flooded the country with re- generative sets of the offensive types. In many loca dition in this plorable. Broadcusters take particular pride in their efforts aged over this situation. The manutacturers have most lities the con- respect is de who are greatly discour worst offenders in the pro- duction of these radio “birdies” are the builders of crude home-made sets. Sad to relate, the receiver is the regenerative simplest, cheapest and effective most type of receiving apparatus for the efforts of the teur builder. ters still sponsible ima To make mat worse, the irre- dealers in radio equipment are forever dress ing up the old receiver in different style selling the parts to the gullible pub- regenerative some = slightly ana lic under a new and high sounding label. Were the regenerative receivers to be placed only in the hands of skilled and radio amateurs, there would be little if ar the unbe coming noises now heard: for, truth to tell, the regen erative receiver when properly a disturbing wave. Note the small conscientious vy of operated does not emit In Great Britain, where our trials and tribulations as pioneers in this radio broadeasting art have been carefully studied, a regenerative receiver of any kind is positively tabooed. A Better Receiver or More Powerful Transmitter— Which? What is the remedy for this condition? That,is a question which broadcasters and the radio industry and listeners-in have been asking themselves, In truth, this is the gravest problem which confronts the broadcasters, apart from the economical quite another story. There seem to be two remedies the present state of the air: first, the use of which will not and cannot emit a wave of any secondly, to bring the transmitter nearer to the receiy which. is sic available in solving rece ivers kind ; ing set either by piling on more power in our present broadcasting stations, or by installing casting stations at various points nearer to the listen ers-in, and operating these stations as a single program sent out mary station, Maintaining its pioneering spirit in the broadcasting field, the Westinghouse taken the initial step toward solving the present situation through more broad “repjenters” of from some central or pri organization has the transmitting end. Instead of placing the burden on the radio audience, this organization has been work- ing out a means of bringing the programs nearer to the receiving sets. Here is how the thing can be done: have a studio in New York, type of programs. In order to bring those programs within reach of the listeners-in throughout the Middle West, let us say, we must operate a powerful somewhere in the Middle West. The are to be re-broadcasted from the Middle West station, which is therefore a repeater station. Two are available for performing this service, one by phone wire transmission between the New York and the Middle West repeater transmitter, and the other by the special wireless transmission of the pro Suppose we broadecusting the finest station same programs methods tea} tele- studio grams—quite distinct from the regular broadecastins wave—the special waves being intercepted at the re peater station by means of a suitable receiver, and then led to the transmitter for re-transmission. Now imagine, if you will, a number of these repeater stations located throughout the United arrangement would give the radio audiences in part of the country the finest programs indirectly from the Gay White Way or from the Nation's Capitol, in ample volume so as to be intercepted with the simplest receiver. Obviously, the repeater station (Continued on page 338) States. This every available,

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304 SCIENTIFIC AMERICAN May, 1924 Experimental Telepathy Tests by Dr. Carl Bruck, M.D., Berlin, on the Transmission of Drawings Adapted by Dr. Alfred Gradenwitz from the Investigator’s Report imme | MEROUS investigators have been at- tracted by the possibility that there exists, apart from the normal channels of com- munication through the recognized senses, a means of contact between human minds, ai means for the interchange of informa- tion and ideas, of such sort as to make appropriate the use of the word “telepathy n characterization, Of those who have entered this belief, some, like Coover of Leland Stanford, have concluded that telepathy does not occur, the apparent instances to the contrary being due to coincidence on the one hand, or to the unrecog- nized (and sometimes tiyperesthetic) operation of the erdinary senses on the other. Investigators of the Brit- ish Society of Psychical Research, on the other, having taken due precautions against these factors, still ob- tained results that indicated the passing of information in some way, which they considered it permissible— or even perhaps necessary—to recognize as telepathic. Admittedly the more startling instances of apparent telepathy are quite spontaneous, and save by the rarest good fortune inaccessible to the investigator. Ad- mittediy the attempt to produce the phenomenon experimentally works under grave disadvan- tages, as compared with the spontaneous opera- tion of the telepathk faculty. But if when we say “telepathy” we mean simply a clairvoy- ance in space or time, or both, operating in a fashion not defined, there seems excellent reason to believe that this may occur, both spontaneously and, less reliably, under experi mental conditions, Perhaps the most or- dinary experimental! is that in which ideas are fixed by means of rough pictures drawn by one experimenter, which the other experimenter attempts to reproduce under conditions of iso- lation against all nor mal communication. The @ attempt to secure such mechanism fot telep athy isolation is not a simple mente: one. The investigator assumes an exceptional degree of scientific and moral responsibility for such sources of error as, apart from conscious and unconscious fraud by the subject, may be due to illusion on the part of the investigator himself. In my own experiments, I have attempted to gain security, against this sort of thing by keeping the drawings in portfolios throughout the test, so that they should be visible to nojody; while in the cases where this was not done, every precaution was taken to insure that there should be no visibility of the drawings to ] through reflection. the subject, either directly or Former experimenters have dealt satisfactorily with such obvious things as mirrors, pictures and window glasses; but they seem often to have overlooked the much more universal reflection on the cornea of the investigator or, When such reflections exist, it need not be asked whether possibly, on his eye-glasses. their perception by the subject would be conscious or unconscious, whether jt would be entirely normal or would involve a visual hyperesthesia. Objections to the use of drawings prepared by my- self and known to nobody else were frequently met by tests with pictures improvised on the moment by other persons present. Such factors as the help possibly de- rived from motive automatisms of experimenter or spectator funconscious whispers, animating mimics, gestures, ete.) likewise had my attention; and I feel that I can guarantee that none of my results were due to ‘“‘muscle reading.” The sittings were under the con- trol of members of the Berlin Medical Society for Psychic Research. No mystic ritual was observed— there was no expectation affecting the mind, but like- wise no intimidation or aggressive skepticism, liable to hamper the subject’s psyche. Fraudulent maneuvers were never observed; all objections and reservations were invariably recorded, even though their futility were immediately realized. Particularly was the choice of too commonplace motifs for the drawings avoided, as well as those which, like the distinction between “ves” and “no,” involved too simple a choice. It would seem that in any experiment to which it is hoped to attach significance, the topic present in the mind or on the paper of the experimenter should be of such sort as to offer the subject, in general terms, a hundred or more alternatives. Any conspicuous success will then * . RR eas 9 The numbers penciled upon the corners of the originals identify these; plain numbers 1, 2, etc.. are while numbers suffixed by a, 6, are the reproductions made, through a process presumed to be telepathic, by the subject or subjects. For full description, see the text Six of Dr. Bruck’s most striking apparent successes in telepathic transmission defy explanation on the ground of chance coincidence. The four persons experimented on in the tests here reported showed intense scientific interest, without any improper secondary intentions. They were young men between 18 and 24 years, civil servants or employes. One never returned after his first (negative) test; a second died after two very fine positive trials. The third, Mr. Z., submitted to 19 tests; but the bulk of the work was done with Mr. R., an unsalaried clerk of 18 in an optical institute. The tests were mostly made under hypnosis; and all four subjects proved easy to hypnotize. Alternating tests with and without hyp nosis were made; and very good results were obtained in simultaneous tests with R and Z, both having their attention centered on the same drawing. The experimenter’s role was limited to a brief indica- tion that, on intense concentration upon the original, this would make its appearance in the subject’s internal perceptive field in such manner as to be readily recog- nized and copied. The results were made known to the subject and to the others present only in toto, at the termination of the sitting; for an immediate announce- ment of failure is known to hamper the psychic mech- anism of the following numbers on the program. Short intervals were allowed between each two individual the drawings tests; nevertheless, fatigue was marked toward the end of each sitting. The summation shows that of 108 *sittings, 20 gave positive results; 32 results of more or less partial sat- isfaction; and 56 were negative. Two cases of failure should be eliminated as due to voluntary or involun- tary suggestion from me, Inasmuch as there is not space here available for complete display of all these tests, only the more remarkable cases will be discussed here. Readers who desire more complete information are referred to the more complete report which will appear in book form (Julius Puttmann, Stuttgart); an English edition of this volume is contemplated. The very first tests, two in number, with Mr. I (the subject who died), were in the deepest somnambulistic hypnosis. These were “open” tests, and in addition to tne ordinary precautions against “mirror telepathy” the subject was seated at right angles to the experimenter rather than opposite him. Referring to this test, Figs. : 1, 1A show a _ surpris- ingly faithful copy of a house with gabled roof, door and two windows. No importance, of course, is to be attached to correct drawing, the main point being the in- clusion of the whole, or of one or two dominant features. On dehypno- tization the subject showed complete am- nesia, not being able to identify the house which he had copied, even when confronted with the original. In the ease (Figs. 2, 2A, 2B) where the orig- inal consisted of the character 6, the _ posi- tive result of Fig. 2A is slightly disguised by a somnambulistic autom- atism following close- ly upon the initial suc- cess. After the six had been properly copied, an auto-suggestive impulse to further drawing en- sued, probably analo gous to automatic writ- ing or automatic art. The somnambulistice au- tomatic component is distinctly seen to follow m after the telepathic one; and a similar sequence was eventually noted, repeatedly, in the case of Mr. R. especially. Figs. 3, 3A, 3B and 4, 4A, 4B—ladder and cup—are portfolio tests with R and Z in simultaneous hypnosis. Mr. R., to whom the A-figures pertain, was the more gifted here, from the artist’s view, and automatic additions are found in the pail and the spoon; whereas, Mr. Z renders only the elements of the original, omitting even the saucer in 4B. Figs. 5, 5A, come from a portfolio test with Mr. R. on a drawing rapidly improvised by one of the specta- tors in an adjoining room. Besides a _ reproduction accurate to the very details of the liqueur glass, there is here an automatic addition, eventually identified as a record from the mind of a little boy belonjing to Mr. R’s circle of acquaintances. All further figures are from tests with Mr. R. In 6, 6A, such details as the wart, the deep folds of the upper lip and the sectional view of the right eye, are particularly evidential. This, like 7, 7A, TB, was a portfolio test, offering no opportunity whatever for conscious or subconscious fraud. In the case of Fig. 7, we have, respectively, the result from using the same original with successive tests in and out of hypnosis. The subjects could not ‘know that the same original was used, even if we ignore the fact that he was in hypnosis the first time. The rhomboids of Fig. 8 illustrate admirably the made by the experi-

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ere May, 1924 reproduction of the characteristic outline of the orig- inal. That this does not always occur, however, but that the subject’s work may be limited to some sig- nificant individual element, appears in Fig. 9, serpent. Let the reader examine the thick head and the tapering half of the tail; the checkered central piece was miss- ing and has been filled in by me. One can easily get here the impression of a defect in the field of meta- psychic vision. Being a portfolio test behind the sub- ject’s back, this is of particular interest; the more so since the same original SCIENTIFIC AMERICAN a key (the dissimilarity of outline is not so pronounced as this statement might imply—kEditor); later, in a repetition at Mr. R’s insistence, the original was repro- duced with great accuracy. In some instances, a rather complicated picture was used, and a description in words asked for rather than a drawing. Thus, two fighting cocks facing one an- other, one being grayish black and the other brownish yellow, brought out a reference to a “black fowl.” Told that the success was but partial, Mr. R asked to make 305 “Or is it possibly some sort of physical transmission of the physiological process of vision or perception from the experimenter to the subject? “Or finally, is it a psychic process arising from sources so far inaccessible to our understanding Only in the event of telesthesia, as well as all other occult phenomena, being due to an exclusively cerebral function, would it be possible to adopt an exclusive psycho-physical viewpoint, or even on a purely physical basis to imagine radiations of some sort from the brain as carrier of the tele pathic faculty. But this was repeated, three times, with the same curious result—the sub- division and gap in the telepathie drawing per- sisted. Fig. 10 (scissors) shows a methodically contin- ued series of tests from the same original. The component elements, the scissors-handle, were re- produced first as dumb- S THIS issue goes to the compositor, we are perfecting plans for an experiment of our own similar to Dr. Bruck’s, but covering a very much greater ground. The experimenters will work from the WOR erally acknowledged, broadcasting station in Newark, and every member of the radio audience who is sufficiently interested may become one of the “subjects” by the simple process of listening in. concentrate upon a succession of numbers, words, objects, pictures, etc., and we shall ask the “‘subjects’’ to try to get an impression of what these are, to record these impressions, and to report to us by mail. should have a number of responses sufficient to make possible a severe statistical treatment of the results, which will be made public in the earliest available issue of the SCIENTIFIC AMERICAN—that of June if the work of compilation is not too arduous, otherwise that of July.— THE EDITOR. We shall have the experimenters exclusively cerebral ac tivity has not been gen even for the psychic phe nomena of the conscious mind; and this lack of W knowledge is clearly e : - seen when Richet em ploys tor the telepathic phenomenon in its en tirety the term “eryt esthesix a term bells and then as pince- nez; and in the final test, made on Mr. R’s express desire because of his only now having the feeling that he was sure of him- self, the original appears in its totality, with much wealth of detail. Numerous experimenters have reported a sort of telepathic lag, in which the drawing upon which a failure had but just been scored, would be successfully reproduced in connection with the next item, taking the place of the true original provided for this; and occa- sionally this lag extends over an even greater interval than consecutive tests. I have had five instances of this: but in Fig. 11 I illustrate the direct reverse phe- nomenon. In this case the original was a bottle; and the subject drew something like a hat. But I was struck with the likeness between the top portion of the original, the stopper with the bottle-neck, and the hat as drawn; so I requested Mr. R to go on drawing. He then left the hat in statu quo, and proceeded to make a new drawing below it, of the top of a street lantern; and this corresponded in every detail to the orig- inal, waiting in the portfolio, for the next test. If the displace- ment in time is to be regarded as a telepathic phenomenon, the antici- pation and the lag must be dealt with and ac- counted for together. A metapsychic explan- ation of anticipation and deferment has been at- tempted on the hypoth- esis that during the sit- ting the subject has tele- pathic access to the whole experimental com- plex prepared by the in- This, of course, is no explana- tion, but merely an al- ternative description of the phenomenon ; withal it seems a very reason- able description. In Fig. 12, a candle- stick with candle was first rendered asa letter balance; it might be disputed whether this was a complete or only a partial failure. But an hour later, when the failure had been made known, Mr. R_ insisted upon a repetition, and faithfully reproduced the original. “ Whether this is a case of deferment or of gradual solution of the task, across an approximat- ing intermediate result, is left to further interpretation of the case. (We assume that Dr. Bruck may be trusted to have made sure that it was not due to the subject's having in the meantime seen the original.—Editor.) Further illustrations are crowded out, but the results of several interesting tests may be described without pictorial representation. A similar case to that of Fig. 12 involved a soup ladle, which was first rendered as vestigator. the test in drawing, and produced two conventionalized curved figures in outline which could be reconciled with the cocks if one were determined to do so, but of which a more accurate estimate would be that their symbolism could not be identified. Over these he ultimately wrote the words “gray” and “yellow,” in the correct order. The existence of two separate figures of unusual out- line had been apprehended, with their color; the exact rendering of their shape had been, quite properly, sub- ordinated. In connection with another descriptive test, employing a black-and-white drawing of spring scenery with shepherd and shepherdess, Mr. R saw a colored scene of autumnal character, with a farm. Moderately satisfactory as showing comprehension of the general effect, this is again inadequate in detail; the test ought, perhaps, have been continued. As long as we can do nothing better than hazard vague guesses as to the psychic process involved in per- Another series of tests in which the “telepathically” received impressions of the subject checked up well with the originals formances of this character, any such interesting details of the phenomena must be carefully kept on record. But so far from suggesting any new hypothesis of telep- athy, experimenters, as a rule, should be content with simple queries. Thus following Prof. Oesterreich, we may ask: “Is it a case of direct television or clairvoyance by the subject with regard to the object (the drawing, for example), without any active cooperation by the experi- menter or any other agent? which amounts in sub Stunce to a clearly stated “ignoramus.” The number of origina! those primarily fitted for the task is tests by inadequate; the theory must therefore of necessity be inudequ ite, In conclusion, a word should be said of the weak point met in all fields of psychic research—the absence of satisfactory results in control and demonstrative tests, which would not in all cases seem to be disposed of by the hypothesis of emotional psychic impediments such as often do make themselves felt. ure, inadequate mental contact with the subject, tem- porary absence of the usual experimenter, we know from the normal experience of normal psychology are likely to lead to failure. With many subjects, individual sug- gestibility is bound to bring about a condition of super- preparedness and enhanced telepathic productivity with regard to customary and sympathetic suzgestions, which under other conditions may be lacking. In the ease of Mr. R., despite a continuous excellent contact The fear of fail with him, a whole a series of failures was often observed under what appeared to be the usual conditions. The intimate cause of such temporary psychic in- disposition will not for the present be under- stood any further than, speaking generally, the similar temporary indis- position is understood in connection with al intellectual and especially with ar- tistic, inspirational ac- tivity. The fact is that all artists, both. produe- activity tive and reproductive, whose achievements are strongly emotional show just this periodicity of effective work. The part, possibly in addition to conscious will and possibiy not, assumed by feelings and emotions, sensations and perceptions, in te- lepathy as well as in other metapsychic phe- nomena, has yet to be ascertained, The ex- haustion observed even by myself and some times by the very spec a tators toward the end of a test sitting, the feeling of disinclination possibly connected therewith, should to some extent account for the presence of temporary disa- bility. Constitutive factors should doubtless be consid- ered as well: puberty, marriage, climate, constitutional health and specific disease infections, possibly even a change in the social medium. The suggestion of good faith inherent in the variability of these, perhaps the most trying of all the phenomena of the mind, is far too strong to be thrown aside at a word from the thoughtless critic. We should expect success to be capricious; and we find it so.

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306 SCIENTIFIC AMERICAN May, 1924 Putting the Atom to Work The Attempt to Isolate its Energy, and to Find How it May be Released for Human Use

iH atomic weight of hydrogen is not es exactly 1, but by careful measure- | | | ment is found to be 1.0077. Who could imagine that in this slight dis- crepancy—which indeed needs some

explanation to make intelligible, > an immense store of possible energy N } is indicated, which some day, when we huve learned how, may become uecessibie fer good or ill to the human race? Let us first expound the meaning of the statement. bare statement that the atomic weight of hydro- whatever un For the gen is 1, or nearly 1, conveys nothing less we know the unit in which it is measured, that unless we is to say, have something to compare it with. For of course all measurements are relative to some thing. Well, it so happens that rather more than a century 18i3 (when the atomic theory of Prout weights of all the taking numbers to be the ago, viz., in the year Dalton was ten that the ascertained, on the made the observation then hydrogen as 1, were too nerly result of chance; and accordingly made that the outstanding discrepancies might be otherwise accounted for. He surmised that they really were whole numbers, and not fractions, se that possibly all the elements were multiples or aggregates of hydrogen. The hypothesis, exciting some in- vears old), atomic elements, as basis of whole the suggestion after By Sir Oliver Lodge, F.R.S. elements, on the supposition that there might be such constituents, could not be done by purely chemical For presumably every constituent which grouped itself about the average value, though it might differ slightly in atomic weight, must have identical chemical properties. Otherwise they would have been separated long and not called by one and the name, The possibility of the existence of such elements — of which the differ in weight but in no other particular, having all their chemical properties exactly and giving the identical spectrum,— suggested itself to Professor Soddy, in connection with his work on radioactivity. And he called them isotopes, meaning that they occupied one and the same place in the chemical series of Mendelejeff. This idea may be 1910. Soon afterwards, in 1912 and 1913, a remarkable method of analysis by physical means in a vacuum tube was invented by Sir J. J. Thomson,— means, ago, same atoms the same, sume dated as of a method known as positive-ray analysis. And this was forthwith applied in an improved form by that indefatigable worker F. W. Aston (who went from with re striking success, confirming to the hilt both speculations and Soddy’s half-ascer- tained results. The simultaneous communication of these vital discoveries, with the assured conclusion that atomic weights were really whole numbers and that all Birmingham to Trinity College, Cambridge, ) markable and Crookes’s the idea that the elements can be built up of hydrogen utoms? <All we can say, so far, is that they appear to be built up of some units which can be counted, and which only occur as integers, not as fractions. Whether this something is or is not a hydrogen atom remains for further exposition. This exposition may be approached in two directions, both strongly confirmatory; one experimental, the other theoretical. Perhaps we had better take the ex- perimental one first, as it is the simpler of the two. The known to consist of massive nuclei surrounded by much lighter electrons. Practically all the atomic weight is in the nucleus. Even in hydrogen, which has the lightest nucleus, it is about 1850 times us massive as an electron. Whereas, in a really heavy utom like uranium, it is 92 times heavier still. Hence, when we speak of the atomic weight we mean the weight of the nucleus. And if the atom is to be built of hydro- utoms ure gen, it must be that the nucleus is so composed. No one imagines that the electrons have anything to do Hydrogen is a positive nucleus with one outlying electron. And if the nuclei are composed of hydrogen, it must be of hydrogen nuclei tightly packed together, so as to form the compound nucleus of heavier atoms. It was known that these nuclei were small compact things, and that they were positively charged; but very little was known about them, until Sir Ernest Rutherford found a means of knocking with hydrogen. else

terest, went into disrepute for a long time; them to pieces, and thus seeing what they

though admittedly a great number of the atomic weights, as determined by chemists were very close to whele numbers, But there were a few exceptions that could not be overcome, of which the most whose atomic weight contriv- notable was chlorine

was unmistakably %; and no ance could make it 35 or 36. If it had devonath been like potassium 39.1, or like iodine 126.9, a little contrivance, or-~assumption of error in experiment, would have al- lowed these to be interpreted as whole numbers. And there were many of the atomic weights in this reasonable posi tion. But there were some that were re- of heat. ealcitrant, not only chlorine, but say sili- formed and dispersed as in nature. tracks of the atoms that globules of water upon these. pass it over here. as heat is simply one of atomic motion. HE series of drawings on the facing page, which we employ as illustrations for Sir Oliver Lodge’s article, was obtained by Mr. Clatworthy, our artist, from Sir William Bragg’s Christmas lecture before the Royal Institution. T. R. Wilson cloud condensation apparatus, in the glass chamber of which clouds are Its object (Fig. Il) is to render actually visible the shoot off from a radioactive substance, by condensing tiny To explain these varied tracks, one must understand the complex structure of the atom, as discussed by Sir Oliver and illustrated in Fig. III. With a dummy billiard table Fig. (A, center figure) (SCIENTIFIC AMERICAN, November, Fig. VI The reverse (Fig. VII, center) also obtains, a gas cooling under expansion. In Fig. VIII, sound waves demonstrably pass between the atoms. Thus these waves I represents the C. and numerous balls representing atoms, Sir William demonstrated the relations existing when one ball attempts to pass the cluster, and demonstrated how empty the center of an atom must be admit the passage of foreign electrons as it does. electrons have thus penetrated the air atoms; in the curved track of Fig. V nucleus has collided with nucleus, resulting in abrupt deflection. The lecturer explained the relation between chemical activity and atomic configura- tion, the reasons why inert gases are inert, etc., present and a preceding article to In the straight track of Fig. IV, the but as Sir Oliver covers this fully in the 1923) is for the purpose of showing that the phenomenon we know The more a gas is compressed, the closer to- gether its atoms lie and the more frequently they will collide—causing the manifestation were built of. The only way to attack them is by their peers. They could not be shattered or got at in any way by any such trivialities as high temperature, ex- treme cold, enormous pressures, chemical explosions, or anything of that kind. They were far beyond the reach of these trifling perturbations. But the projectiles fired off by radium, at a speed of several thous- and miles a second, were not so insignifi- eant. And Rutherford arranged to bom- bard the nucleus of any desired atom by means of these projectiles. They were targets excessively difficult to hit because they were so ultra-minute; and thousands of shots might go by them without achiev- we may con, which was 28.3, and magnesium, eave) meee quickly in hydrogen Gen in Ge denser oxygen. a ial ing anything. But then hundreds of hich s 2942 . —_ ‘ ing pressure of a gas is simply the mbardment of the surrounding walls by its tl sands of ; Ss were available. any whi 7 was 24.3. And the outst andi atoms. The atoms of a gas can also obstruct those of a solid (Fig. IX), or of a liquid nore is of shots were available, any fractions were more than could easily be (Fig. X). In a solid, the constituent atoms are firmly united; in a liquid they are in number in fact; so that sooner or later got rid of. Hence, though there was touch, but not permanently, for they change partnership continually; whereas, in a gas there was bound to be a hit. And then something admittedly puzzling about the

all the atoms move about independently and arbitrarily. something happened. Briefly. the nucleus

near approximation to whole numbers, the hypothesis of Prout that all the elements could be built up of hydrogen, with the atomic weight 1, fell into discredit. Nevertheless it was not aitogether killed. For Sir William Crookes in 1886, at a meeting of the British Association in Rirmingham, made a suggestion that perhaps the elements were not such simple and well defined things, and the weights not quite so numerically definite, as thought; that what atomic had been we call magnesium, for instance, might possibly not be a single substance but a sort of average, a certain proportion with atemie weight 24, mixed with another smaller proportion of atomic weight, say 25 or 26,— the proportion so adjusted that the combined weight should come out 24.3, or thereabouts. In other words that the experimentally determined atomic weights were averages rather than exact figures; though admit- tedly chemical skill allowed these averages to be deter- mined with surprising ac¢

uracy. It is worth while to quote Crookes’s words in this connection, published as they were so long before any verification was possible This is what he said:— “IT conceive, therefore, that when we say the atomic weight of, for instance, calcium is 40, we really express the fact that, while the majority of calcium atoms have an actual weight of 40, are not a few which are represented by 39 or 41, a less number by atomic there 38 or 42, and so on.” This, when thrown out, was only a hypothesis, a guess, a suggestion. Or, as Crookes himself called it, “an audacious speculation.” But, like many of Sir William Crookes’s ideas, it was based upon an instinct not to be despised, and was worthy of such testing as time, no such method was constituents of might be possible. At the available. The discrimination of the the fractional part was due to a mixture of different whole-number isotopic ingredients, was made to the British Association at Birmingham in 1913; one to the Chemical and one to the Physical Section, by Soddy and by Aston respectively, 27 years after Crookes had thrown out his suggestion in the same city. Aston was able to show that chlorine, with its atomic weight 35%, or with greatest accuracy 35.46, was really a mixture, in unequal proportion, of two elements exactly like chlorine and occupying the same place in the periodic table, so that they could be appro- priately called isotopes; but of which the atomic weight of one was 35 and that of the other 37, the proportions heing about three of the lighter to one of the heavier elements. And again that silicon, with its atomic weight 28.3, was an admixture of two real elements, 28 and 29. Not all the so-called elements are mixtures. Carbon, for instance is exactly 12, nitrogen exactly 14. Mag- nesium is a mixture of three, with atomic weights 24, 25, and 26. And argon, though most of its atomic weight is 40, seems to have a slight admixture of a similar substance weighing only 36. But now on what scale are these numbers specified? What is the unit? Well the unit that shall make some one of these elements of simple constitution exactly a whole number; and the seale chosen is that oxygen shall be 16. Then all the others fall into place. On that seale carbon is exactly 12 and helium exactly is such 4. But, strange to say, hydrogen is not exactly 1, and no amount of contrivance can make it 1. It is 1.0077. How then can we say that Prout’s ancient hypothe- sis is substantiated, or that there is any probability in broke up, and hydrogen flew out of it. The evidence for this must be read in Rutherford’s papers. The evidence is given for the propulsion of a quick-flying hydrogen atom driven out of the nucleus by the bombardment. Well, this was pretty direct evidence that the nucleus contained hydrogen, or at least contained it in the same that water contains it. For hydrogen can be driven out of water by an electric current; in that case, it is true, a very perceptible or possibly a large amount, whereas, in Rutherford’s experiments only one or two atoms are ejected. But we are accustomed to deal with atoms nowadays and to recognize them individ ually. And the evidence is sound. It does not prove that the atom is built of hydrogen and nothing else ; but it proves that hydrogen is one ingredient. What else was knocked out of it? Atoms of helium. But we knew that atoms of helium were there before, at any rate in many atoms, for they are spontaneously ejected during radioactivity. Hence, it looks as if everything was built of hydrogen and helium. So now we have to consider what helium is built of. Its atomic weight is four, exactly a whole number. Hence, if hydrogen were 1, we should have little doubt that it was built of four atoms of hydrogen, very closely compacted together. But the atom of hydrogen heavy for that. It is not 1: it is 1.007. How can we say then that four atoms of hydrogen can by any possibility build an atom of helium? Well, here comes the theoretical part of the exposi- tion, the part which I said was rather hard. We have now to enter upon the electrical theory of matter. We know now that matter is electrically constituted, and that what we call its inertia is really due to the mag- netic field of moving electric charges, that inertia is (Continued on page 358) sense seems too

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May, 1924 SCIENTIFIC AMERICAN all of Piston blackened surface ) exhands Air .ccoling i and causing Condensation Prieeng vet pati of Chamber seen from above AB A&B Radiating Afoms turned into Electrical Conductors by M~-Raus .causing moisture to ; condense uhon them in tracks of tiny . visible globules Atoms encounter as in Track A (ys NUCL EUS, charged | ; me tricity Leap Weyer talent arellite ELEC tive electricity irling Aboutl Nucleus. Their pumibers vary from in Hydrogen onto. 2 Pluncer trrvell i se nig Original oo Volume of iInflAant-. ina ble ¢ GOs collide AS Track B Mofion of Atoms violenity accelerated . causing tahid healing ard Combustion id ‘ THE INTERNAL MECHANISM OF THE ATOM, AS DEMONSTRATED AT A RECENT LONDON LECTURE

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308 SCIENTIFIC AMERICAN May, 1924 ur Point of View The Mischievous Pen World War tumbled emperors from their and placed the destinies of nations more directly in the hands of the people. A rable change, provided the masses are instructed on matters of domestic and for kept fully eign policy Under the old order the potentate was well informed, particuianriy on the international situa- tion His embassies und secret service saw to that. Today, the masses, the great body of the voting popu- ‘ lation, are dependent for their knowledge of world affairs upon the press; and more particularly upon the special correspondent and the so-called special writer. In former days the emperor “rattled the saber”; today the press rattles the pen Qur Wwar-stricken vorld understands, oniy too well, What evils may come of saber-raitling: and unless the owners of the great journalistic organs of the day muzzle their correspond- ents, the world will find out, to its infinite loss and agony, that the pen as a breeder of war, may be even “mightier than the sword.” But would you have the owner of a great daily muzzle his staff? Most assur- edly we would, to the extent of his laying it down as a law never to be broken, that the correspondent, special writer, or what-not shall deal in facts only and not in his own sensational and war-breeding interpretation of the facts. Of a vast number of the people it may be said that, mce they have left the public school, their their winches were pulled out of the ship and the two forward gas bags were torn open. The violent rupture of all this metal work must surely have been accompa- nied by frictional spurks and this occurring in the pres- ence of liberated hydrogen would probably have resulted in fire or explosion, or both. Surely it is not claiming too much to say that it was her helium that saved “Shenandoah” and her crew from instant and over- whelming disaster. Against the advantage of safety is to be set the scarcity and cost of helium and the fact that its lifting capacity is about 7 per cent less than hydrogen. The operating losses of the gas may be reduced by recover- ing the water from the engine exhaust, and maybe, though this is at present impossible, by some method of compressing the gas into cylinders instead of venting it into the air. The Good Old Times HERE is a romance about the past which finds expression in the phrase “the good old times.” But, outside of their leisurely ways as com- pared with our modern rush, are we sure that these old times were so very good? Listen to the follow- ing, culled from our contemporary The Engineer, which refers in a recent issue to an address, given in 1864 by the President of the South Wales Institute of Engineers, when that gentleman described the shocking pouring of humanity from your Brobdingnagian build- ings. Whether in play or at work, you swarm as do the bees; and of distinctive individuality I see no very marked signs.” Panama Canal Sufficient s}i2 have had oecasion to point out the fallacy of claiming that because of the recent rapid in- crease in the traflic passing through the Pan- ama Canal, the United States should begin to consider the construction of a second canal, preferably at Nicaragua. It is questionable whether Nicaragua would prove to be the most desirable location. The great length of the route and the engineering difficulties arising from the topographical conditions, to say noth- ing of its nearness to the earthquake zone, combine to east a serious doubt upon such a project. The cost moreover would be prodigious. To tell the truth there is no question of the ability of.the Panama Canal to take care of future tratlic for many decades to come. In spite of the gratifying growth of traflic, the canal as it stands hus a wide margin of capacity. Even under its present limited hours of operation there is room for considerable increase in shipping; and when it is thrown open for night traffic, and is in service for the whole twenty-four hours of the day, its capacity will suffice for any prob- able increase in the near future. When the time comes for enlargement sole source of education is the daily news- of facilities, it will not be necessary to go paper. They read nothing else: unless it be an occasional novel from the nearest Carnegie library. And such people (whose ordered education ceased with the public H school) have a pathetic faith in the in- T fallible authority of the press. “I saw it in the paper”’—and that set- tles the matter. Hence the masses of mankind are made to believe that Japan dreams of capturing our Pacific coast; that France aims at the military domi- nation of Europe; that Germany has se- cretiy re-armed herself with a huge aerial fieet and is ready to drench Europe with WARNING SCIENTIFIC AMERICAN PUBLISHING CO. elsewhere. By building an additional pair of locks, adjacent to those at Gatun, Miraflores and Miguel, and building a E readers of this magazine and the public are again new reservoir at Alajuela, in the upper advised that its publishers have no connection whatsoever with the Encyclopedia Americana Corpora- tion, publishers of the Encyclopedia Americana, or its associate organization The Scientific American Compil- The recent remarkable increase in the ing Department, and this warning is given to prevent the confusing of the SCIENTIFIC AMERICAN with any other publication, periodical or business enterprise. Chagres river, the capacity of the canal of that day may be doubled, and all anx iety for the future removed to a far dis tant day. tonnage passing through Panama has been due, mainly, to the opening up of certain very rich oil fields, mainly in California, and the fact that the oil can be carried to the Eastern refineries via the canal more cheaply than by any other route. These poison gas. The King of Spain pays a friendly visit to the King of Italy, and forthwith your Buroepean correspondent pictures a new European bone of contention—the control of the Medi- terranean. The Caliph is expelled from Constantinople ; next day you @re assured that Great Britain would have an Arabian Caliph, France a Morocean, and that herein lies another cause of friction and ultimately of war. Helium as a Life-saver awe) CORRESPONDENT very properly takes us to A tusk for not having mentioned, in our recent article on the “Shenandoah,” that she uses helium instead of hydrogen. The omission was due to familiarity: to think of “Shenandoah” was, for the writer, to think of helium and, so, familiarity hred not contempt but omission. As a matter of fact the writer considers that the most distinctive feature of the ship is the helium that lifts and supports her. To this remarkable gus she owes her great superiority over all other airships. She cannot be rent asunder by explosion; nor can she suddenly be converted into a fiaming funeral pyre for the whole of her officers and crew. To realize what this means we have only to call to mind the horrible fate of “ZR-1" at Hull, England: of “Roma” at Hampton Roads: and of “Dixmude” off the coast of Ltaly. Lightning destroyed the “Dixmude” ; sparking, of static or broken-wire origin, set fire to the other two; and it is a fairly safe guess that, had “Shenandoah” been filled with hydrogen when she was torn from her mast, there would have been another holocaust to record. For when the ship broke loose, several things happened simultaneously. Not only were a dozen longitudinal girders torn asunder, but the steel landing cables and conditions attending coal mining in Scotland prior to the year 1800. It seems that the collier left home at eleven in the evening and prepared the coals by “hew- ing them down from the wall.” His wife and daughters followed him three hours later, and descended the pit with baskets, which they filled with coal and carried on their backs to the pit bottom, the mother going first with a lighted candle held between her teeth. From the pit bottom these women carried their loads up the steps to the surface, and in eight to ten hours’ time one woman might carry through the mine and up to the surface a total load of two tons, traversing a distance of nearly six miles, and climbing one hundred feet by the stairs, 24 times in succession. Such were the good old times of the middle of the eighteenth century, when a man was hung for stealing a sheep and lesser infractions of the law were rewarded on the same ferocious scale. If the thoughtful among us speak of the good old times, it is because we are conscious of the high pressure and unending strain of our highly industrialized civilization. In such a mood one may long for the comparative quiet and rest- fulness of far-away days. But what would Shakespeare have to say, if we could bring him back to life; take him into the subway jam during the morning or even- ing rush hours; and let him be catapulted by the center rush into a tightly-wedged mass of humanity in an Interborough car? Or let us bring the great Dr. John- son from his London Coffee House, and take him for a stroll down Broadway in the closing hours of the Wall Street district. “Sir,” he would say, “I have turned over many an anthill with my boot, and seen no stream of insects to equal in numbers and density this out- western oil fields have about reached the peak of their production; and future canal traffic may be slowed down by the withdrawal of these tankers. The Oil Delusion HERE is no money in oil (now please do not get excited), except for the very few. Thisis a startling statement and we would not make it except upon the best authority, which in S. Geological Survey. As their lead- this case is the U. ing geologist said to the Editor the other day “Oil pro- ducers, as a class, lose money; though some make lots of money,” and he went on to say, “that, by and large, including the ‘wildcat’ ventures, it costs more to get oil to the customer than the customer pays.” Consider the State of Oklahoma, where, a few weeks ago, oil was sold at $1.75 per barrel. To begin with, the prospective millionaire must pay out on an average $40,000 for drilling his well, and it will cost him about 15e per barrel to raise the oil during the flow. Pump- ing, on an average, will cost him from 80c to $1.00 per barrel. He must reckon in the interest on his invest- ment of $40,000; and the well must pay its share in the general overhead of the company. Also it must pay its share of the original cost of the lease. Finally, all of the above items have to be taken from seven-eighths of the oil, since one-eighth, let us say, of the oil goes to the lessor. This estimate of seven-eighths of the oil to the operator is very liberal; for in some cases the terms may be drawn on a basis of as high as one- fifth of the oil to the lessor. By the time these costs have been deducted from the $1.75 received for the oil, we are prepared to believe that the “money from oil is made from the crude at the well on to the consumer.”

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May, 1924 SCIENTIFIC AMERICAN 369 Here and There pee months ago we saw statistics indicating that the number of cars stolen each year in a group of exceeds the total number in operation in important as Japan and Czecho-Slovakiu—several others were named, but these We decided at the time that this was the most picturesque and convincing demon- stration that ever had the unchallenged place of the United States at the head of the motoring world, and that we should never again this any So in the presence of the latest leading American cities countries as two alone we remember, been or ever could be made of try to illustrate point by other citation of figures than this one. automobile census, as of 1923, we remark merely that there are today, by closest count and estimate possible, 18,241,477 automobiles in use throughout the world. It's a mighty big oak that has grown from the acorn planted two decades ago by Messrs. Ford, Olds, Haynes, Duryea, Rolls, Panhard, et al. Among the foreign na- Britain has 655,000 cars; Canada 643,000 ; 160,000, tralia and Argentine—the totals exceed tions, Great and France In three others—Germany, Aus- 100,000, URING the coming summer, Mars will come within 31,000,000 the earth, something like 20,- 000,000 miles nearer than is his custom, and his closest century. Naturally, the astronomers the details of the Martian geography are preparing to take advantage of the occasion; and a lot of people who cannot discharge miles of approach in more than a who are interested in their minds of the suspicion that Mars may be inhabited are getting as excited as could be expected over the their the question of communication with Mars leaves us abso- prospect of proving case. For ourselves, lutely cold. Whatever the attempt might cost, from ten cents to twenty million dollars, we could very easily spend in a better scientific cause. Ty’ HE dinosaur eggs which occupied the front pages of the newspapers, and one of the inside pages of the ScIENTIFIC AMERICAN, not so long since, are not the only prehistoric things of their kind. South comes to the fore with a collection of fos- Dakota now three miles. Is it any wonder that with such an appa- ratus, Dr. Coblentz can measure the heat which we re- individual stars? We rise to remark that the Doctor carries his fifty years very well, if one may judge from his picture. ceive from LLUSIONS to the siege of Troy are contained in inscriptions on ancient clay tablets dating back a dozen centuries before Christ, according to German in- vestigators who have these tablets in charge and under examination in Berlin. The tablets, brought from the Hittite country by Hugo Winkler, are 11,000 in number; and while not deciphered, given up enough proper lend the theory that they deal with Troy and other Homeric topics. In addition to the famous siege, it is that the tablets include treaties historical matter of prime importance. have support to completely names to believed and Our informant specify, but we presume that the language is that of the Hittites, which up to this date defied all efforts at translation by modern scholars. texts of other does not has NCE upon a time, in tell- ing the tale of modern in- dustrial chemistry to the lay- man, it Was necessary to start explanation of why is one of the most of all manufactured with ap ummonia essential! chemical products, and a cor- nerstone of all chemical in- Today we that the general reader knows tell advance in dustries, assume and we each further so much, story of the production of ammonia on a P ‘ . P ° rt r . its own merits, without refer- vom, Seis © Lamb ence back to the general problem fixation. f nitrogen Prof. Arthur B. Lamb, director of the chemical labora tory at Harvard and of the Fixed Nitrogen Laboratory in Washington, is the the gressing attack upon this preblem. He latest figure in ever-pro has discovered a new catalyst—its chemical identity is HE Lord Kelvin Gold Medal for 1924, has been awarded to Professor Elihu Thomson, one of the world’s most eminent electrical first engineers. Professor Thomson is the American to this award, which is made every three years mark in original re- work in engineering. Professor Thomson got an early start in his profes- sion, and was one of the moving spirits in the old Lynn, Mass., shops which later receive as a of distinction search not yet revealed—which will bring about the direct union of hydrogen and nitro- gen, yielding among other products the precious ammonia, and in larger amounts than by older processes. HE subject of catalysis itself is one of chemistry’s romances. Dr. Hendrick the equally has called chemical go between. analogy would be to call it the chemical the catalyst Perhaps an pertinent lawyer, or even the chemical court of do- formed one of the integral parts of the General Electric combine. Professor Thomson’s inventions in dynamo-electric machinery, electric welding, watt-hour meters, lightning arresters and magnetic are extinguishers funda- and in all, he granted 700 United States patents. He was a pioneer in are light- ing, and innumerable electrical devices have been im- proved through his work. In addition to are mental ; has been about silized eggs, turned up in her “bad lands” his research work, he has always been ac- by Professor H. W. Nichols, curator of geology at the Field Museum, very much than the dinosaur eggs, being the produc- assistant Chicago. These are smaller tion of a small bird, apparently bearing some resemblance to the duck of today. The photographer who supplies Professor Nichols’ picture for mention by informing us these duck eggs qualifies honorable are believed to be older than any other relic of animal life now existing, with the exception of the dinosaur eggs from “Mag- tive in educational circles, having started in the Central High School of Philadel- phia, and being now identified with the Massachusetts Institute of Technology. The Lord Kelvin Medal is merely the latest of numerous similar honors which have come his way. noelia.” As a photographer, however, he is reliable; despite his weak geography, we have no hesitation in presenting his print as really representing the face of Prof. Nichols! NE of the most active inventors among the scien- tists of the day is the sharp-faced individual at the left corner of the page—Dr. William W. Cob- lentz of the Bureau of Stand- ards. If Dr. Coblentz were to be characterized professional- ly, it would probably be as an lower astro-physicist. One of his particular specialties is the study of the heat radiated from the stars and planets; and in this field he has de- vised most of the standard in- struments now in use. The photograph shows him squint- ing into the eye-piece of a radiometer so sensitive that it will detect the heat given off from a candle at a distance of Dr. W. W. Coblentz Prof. H. W. Nichols UMEROUS are the ambitious souls who visualize the immediate commer- cialization of the airplane upon a large scale, so that regular passenger service between New York and San Francisco, London and Australia, Paris and the heart of Africa, may be looked for by nine o’clock tomorrow morning at the very latest. Well, we have the many short lines in Europe, of which those crossing the Channel are apparently the most prosper- ous: but when the distance covered begins to run up into the hundreds of miles, the commercial difficulties of the promoters begin to outstrip even the technical Thus, the British Government has just gone on record as refusing to back a project for service to India and Australia, and as a result the promoter has had Those who have contemplated ones, to abandon his scheme. trusting their money to such projects as well as those who would contemplate trusting them with their lives, can well afford to look upon them more conservatively than is the custom. The plain facts are that we are not ready for long-range airplane service on any more ambitious scale than that now followed by Uncle Sam in his transport of mail, and it will be an indefinite period before we are ready. For long distances, it seems a safe prediction that the airship will precede the airplane in the commercialization of aerial navigation. successful Prof. Elihu Thomson liti- agree may—if mestic relations. Two gants who simply cannot prospe ctive the lawyers are the right kind to agree through their lawyers. lieve it utterly impossible to live together in harmony find, in the presence of the skilled adjuster of domestic entanglements, that it And two chemicals that will one another, under ordinary circumstances, if gether in the presence of a third substance, form a perfectly good union. The lawyer isn’t used up, the judge isn’t used up; both are available to bring about subsequent And used up, either; it stays in the retort, while batch after batch of raw put in, and batch batch of the finished product taken out. Platinum is one of the best known of catalysts, but there are plenty of others, and it is one whose catalytic properties have heretofore been unknown that Professor Lamb has un- earthed. manage Two persons who be isn’t impossible after ali. have nothing to do with brought to- will perhaps reactions. the catalyst isn’t materials are after E ARE rather in the habit of looking upon the modern city as the haunt of man alone, and assum- ing that wild animal life must confined to the rural true that the game animals shun the residence of man; but none the less we necessarily be sections. It is of course animal life in our cities, and this uncensused fauna makes its presence objectionably felt from time to time. Rat Bites Sleeping Infant and Fights Man’—so the headline of the morning paper fine March. The text is not confined te the specific instance of the head, but quotes a Health Department official to the effect that the estimates that New York has a rat population of 3,000,- 000: that no than 22,000 of rodents killed annually by human agency; that next to the fire hazard, they constitute the greatest single source Mice ‘and just two other examples to show that our cities are have a very considerable spontaneous “Huge reads this day in war against rats is hopeless. He more these are and of property loss in the city. tramp cats are not quite so exclusively given over to human habitation habituated to thinking. Nor is it at all unusual for these and other, ordinarily display very keen fighting capacity as we are shy, species, to when cornered, 80 that it is by no means a hyperbole to speak of the wild animal life of our cities.

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310 SCIENTIFIC AMERICAN May, 1924 The Story of Steel—V Bessemer Converter, Where Air Performs the Major Process in Steel Making | zeeeamen scams x |S chapter LV of the Story of Steel, we saw iF $0 that in the blast furnace iron was sepa- i rated from iron ore by meats of the fierce | heat resulting from the combustion of | | coke, through which great volumes of ’ heated air were continually being driven. The resulting metal, as it is tapped from the bottom of the furnace, is liquid cast iron, or “pig” as the fur- nace man calls it. Now, although cast iron is a useful metal in the con structive arts, its range of ust by the fact that, high, its bending and tensile strength ure low. It the ductility, toughness, elasticity, and all-round strength The excessive amount oi that in stituent of household ‘fulness is greatly limited theugh its compressive strength is lacks of steel, ubsence of these qualities is due to the carbon present, us compared with steel. There is ulso an excess of Silica, a con sund and recks; phosphorus, as used on the match, sulfur, which the “kiddies” used to tuke (und may do yet, for all we know) in “sulfur and molasses,” and munganese, And as fire is used to get the iron out of the iron ore, so fire is used to turn the iron into steel. This it does by burning out the in the Furnace. England by 1855 was an epoch making invention industry. By many, be- cause of its revolutionary effect on modern industry, it is regarded as the greatest of all inventions; for with out it the production of cheap steel in unlimited quan tities would wus admirably adapted to all tent. hearth furnace of Siemens-Martin was developed; and that are high Today, s made by the Bessemer and i liearth method. above-named impurities, either mverter or in the Open-Hearth Converter, developed in Bessemer C The Bessemer Henry Bessemer about in the steel been that iow in As the choicer ores became depleted, the open- have impossible. It ores were phosphorus con- in this furnace ores in phosphorus can about 25 per cent of 75 per cent by I be treated successfully. the steel the Open- Steelmaking, spectacular ail the Missabe to the and-one shapes in the mill is highly mines at thousand- but nowhere does it present as the editor recently saw it, the vast open into its way from rolling of the steel such a dramatic and awe-inspiring sight as in the con- verting mill. The converter is from 10 to 16 feet 20 feet in height. Ii bottom, drawn in at the top, a barrel-shaped steel vessel, varying in interior diameter, and from 12 to is closed at the and is as suown in the sectional view on the adjoining page. At its mid- height it is supported on trunnions. An air pipe is led in through one of the trunnions and continues down to chamber in the the The interior is lined with material to protect the from the fierce heat. The bottem is perforated an air base of converter, 12 to 18 inches of refractory steel shell with from 150 to 200 one-half-inch holes, leading from the air chamber to the interior of the converter. Now let us return to the blast fur- nace. Here, at intervals of every four hours, the clay plug which seals bottom of the and the run into a train of drawn by a the outlet from the furnace is broken iron 1s which are through molten steel ladles, locomotive to the mixer, a large hori eylinder, hold The mixer is part of the plant of t Works, Chicago, of the Illinois The obiect of the mixer is from which zontal which can at one time of is lined with firebrick, 1300 tons of metal here spoken he South Steel Company. to form a iarge the hot quired by the converters From the mixer rotating the reservoir, metal can be drawn as re the hot metal is s xer on its into emptied by ixis, and pouring its contents ladles for The converter is turned down into a horizontal position, and a charge of 10 to 25 is poured in from the ladle. The air blast is then turned on and the converter swung back into the vertical position. The air, under 25 pounds to the square inch, iron in from 150 tY insport to the converters tons a pressure of about VO to is now forced up through the molten to 200 separate streams, and its oxygen, combining with the carbon, silica and manganese in the iron, sets up a violent combustion, and raises the temperature of the muss until it reaches the stage known as the boil. The process continues for from 10 to 15 minutes, at the close of which all of the impurities and practically all of the j Section through the electrical furnace shown below. The current passing through the three 20-inch elec- trodes and the metal charge raises the temperature to as high as from 2850 to 3000 degrees curbon have been burned out and only pure iron remains, The oxygen of the air first burns away the silica and manganese and finally the carbon. The color and density of the flame issuing from the mouth of the con- verter clearly indicate to the skilled operator what is going on inside. As the silica and carbon begin to burn, an orange-yellow flame, edged with blue, streams from To the left is a 25-ton electric furnace; to the right a ladle is discharging molten iron into the furnace for treatment the nose of the vessel. Then, as the carbon begins to burn there is a change to a bright flickering flame which rushes violently forth, accompanied with great streams Then the flame down, The from 10 to 15 minutes; but the fierce com- raises the temperature of the metal in that of sparks. dies lasts only bustion process short time from 2000 degrees to us high as 3000 degrees. We have spoken of the spectacular effect afforded by a converter mill in full blast. The agitation of the molten mass, as the air mashes through it, produces a dull reverberation, which mingles its deep note with the steady roar of the hot and brilliantly colored gases, as they pour from the mouth of the converter. Every now and again small particles of white-hot metal are thrown high into the air and fall in a thick rain of brilliant coruscations to the ground. A good impres- sion of these effects can be gained from the colored cover of our April issue, which shows a converter in full blast. But the mere burning out of the undesirable elements does not give us steel; for what we have left in the con verter is merely an unadulterated and “characterless” iron. It must now be changed into steel by putting back into it, with great exactness, a certain amount of carbon, manganese, silica or other substances to pro duce the kind of steel required. Accordingly, after the converter is turned over and before its contents are poured into a ladle, a carefully weighed amount of these substances in the form, let us say, of spiegeleisen. is introduced in molten form into the converter, to give the small amount of manganese, silica and carbon required in the finished steel. The ladle is now lifted and a train of cast-iron ingot molds, with two or three molds to the truck, is drawn beneath the “pouring stand,” and the steel is run into the molds through a nozzle in the base of the ladle. The converter has been replaced very largely by the open-hearth furnace, which is capable of handling satisfactorily iron made from in- ferior grades of containing large percentages of phosphorus. The converter work upon the metal in from 10 to 15 minutes, whereas the open hearth requires from seven to 12 hours, Speaking broadly, the open-hearth permits the metal- lurgist to keep in closer touch with the reactions that are going on within the furnace, and, by skillful treat- ment, he is able to with accuracy the exact amounts of carbon, manganese, etc., necessary to give him the steel which he wishes to produce. Excellent as the open hearth furnace process is, the steel even better results by using the electric are as his source of heat in the fur nace. Much experimental work has been done, and out of this has the Heroult elec tric furnace, of which we show a photograph and cross-section on this page. The Illinois Steel Company have been very accurate and success ful in the development and use of electric refining, and the two 25-ton furnaces shown in our photograph are among the largest and most suc- cessful in existence. The United States Steel Corporation has four of these 25-ton electric furnaces, and the Corporation built two 40-ton Heroult electric furnaces for the United States Navy. which operated very fully during the war at the U. S. N. Ordnance Plant at So. Charleston, Bessemer basic ore Bessemer does its process secure maker has aimed to get come success W. Va. The furnace, 16 feet in diameter, has a plate-steel shell one inch in thickness. The bottom is carried on toothed rockers and tracks, on which the furnace is tilted to empty its con- tents. The large wheels shown are geared to a 140-horsepower motor, which tilts the furnace, by means of a connecting red. The furnace is lined with three different materials: first 414 inches of fire-brick; next to that a lining of magnesite brick 9 to 1344 inches in thickness; and above — the last named is spread about 13 inches of dead, burned magnesite. The dome-shaped roof, 12 inches thick, is of silica brick. In the roof are three equally spaced openings for the electrodes, 20 inches in diam- eter, which are formed of amorphous carbon. They are carried by horizontal arms that project over the furnace from heavy, vertically moving rods. Heavy copper cables and copper bars carry the current from (Continued on page 366)

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312 SCIENTIFIC AMERICAN When, Where, Why? MAY, 1924 How Cennecticut Gathers the Data of Her Automobile Accidents, and the Use She Makes Thereof R consideration of the automobile trattic problem hes been centered, to date, upon the question of uniformity of law. But this is far from the whole story. In the end, the traffic problera is entirely a mat- ter of accident prevention; for if there were no accidents we should be unconscious of any preblem. Now uniform laws would be of great value in preventing accidents; but the accidents that occur are of such various sorts and arise from such various cuuses, that neither this nor any other single measure, however desirable and important, will prevent them all. In view of this complexity, the first step in accident pre- vention is to come to a thoreugh understanding of the ways in which, the circumstances under which and the reasons why accidents occur. If we are thus to attempt the collection of data re- garding accidents, we must get it, in the first instance, from the people to whom the accidents happen. In most cases, one or more of the parties to an accident has a motive for the suppression of facts. By the SCIENTIFIC AMERICAN Staff police. The Commissioner shall take such action as may be necessary to enforce a strict compliance with the provisions of this section.” This statute would be improved by a specific requirement that each driver establish his identity with the other, and a really skill- ful punctuator could distribute the commas in such a Way as not to value personal injuries at ten dollars, up; but in the large rather than in such detail suggestion for betterment goes by default. The necessity and the utility of such close official pursuit of those involved in a motor accident will not often be questioned. If the practice were attacked, however, no better means of supporting it would be available than a thorough examination of the entire procedure in Connecticut—a survey of just how the Commissioner collects these accident data, and of just what he does with the information after he gets it. If you have an accident while driving in Connecticut, the law contemplates that you will so report to the Commissioner; and by return mail you get a blank to railroad train, team, bicycle, pedestrian, fence, tele- graph pole, road obstruction or another automobile as the thing with which you got tangled up. Next, about your own car. Name, age, sex, address, number and date of operator’s license; and did you have it with you? If under instruction, give these de- tails about the licensed operator who was with you. How many years have you held Connecticut license? Did you operate car as owner, or as employee or friend of owner? How long have you operated this particular car, and when did you last test its brakes? Were you operating for hire, business, or pleasure? Give regis- tration number, make, type and year of car, with own- er’s name and address. State condition of brakes and horn, make of lens, and character of lamps (electric, gas or oil). Estimate the extent of damage to the vehicle, and describe said damage. You are not expected to know quite so much about the other fellow’s car. Name, sex, license number and address of operator; name of owner; make, type and registration number; condition of brakes Hence it is obvious that we can get at the facts only under the authority of the law, through agencies established by the law, and with the distinct backing of the law. Reverting for the moment to the uni- formity theme, we find that our several state codes show the widest divergence in the extent to which and the way in which they provide for official examination of accidents. Of a handful of motor-law pamphlets which we select mainly on the ground of the easy accessibility of their contents, these of New Hampshire and Minnesota appear to make ne demands upon the parties to an accident Idaho, Maryland, South Carolina, Nebraska and California require only the giving of any necessary assistance to the other fellow, pilus the exchange of numbers, names, ad- dresses, etc. Oregon demands that the recipient of such information make a written memorandum of it—a useful idea ; Washington is unusually explicit in for- bidding either party to move from the spot before establishing his identity. Numerous states go further than this. To the requirement of identification, Kan- sas adds the demand that, “in case of death or serious injury,” resulting from the accident, report shall be made to the nearest police or peace officer; but one wonders where one’s respensibility for knowledge that “serious injury” has been inflicted begins, and one wonders also how to interpret the provision that the person so far as you know; appraisal and de- scription of the damage to it. Then you are given a place to tell who was hurt, and how, and to estimate and describe property damage other than to the ve- hicle. If a third vehicle was involved, there is space to tell about it, too. Then there is a place to give the name and rank of any police officer present at the scene, to state who was arrested or summoned (the ordinary police jurisdic- tion over the accident itself is in no way impaired by the Commissioner's investi- gating powers), and to record the names and addresses of the witnesses. The text of the blank duly impresses upon you the necessity of getting a complete collection of these names. Finally you are asked to indulge in literary composition to the extent of not more than ten lines, giving the circum- stances surrounding the accident—‘state when you first realized that an accident would happen, and give in detail how it happened and what occurred after it.” Six characteristic road lay-outs are print- ed in outlined diagram—a straight stretch, u curve, a square cross-roads, an oblique one, an offset square one, and a Y-fork; and on one of these, or on a fresh one made to order if none of them applies, you are invited to diagram the accident, using conventional symbols for a car or truck, a team, a motor- or foot-bicycle and a pedestrian, and indicating direction of “causing” the accident do the reporting, Utah’s law is much clearer, making it ob- ligatory upon all the drivers involved to report, in all cases resulting in personal injury of any sort. New York makes the same demand, in very precise language, of all those involved in an accident that results in per- sonal injury or damage to a vehicle. LTllinois attempts the same thing. But where New York explicitly re- quires the exchange of identifications in addition to the report, Illinois seems to give one the option between telling the other driver and telling the police. Massa- chusetts, Rhode Island and Connecticut have substan- tially identical laws which carry the examination of accidents by official action to its climax. We quote the statute of the Nutmeg State. “The operator, whether resident or non-resident, of any motor vehicle involved in an accident resulting in personal injury or damage to property to an apparent extent in excess of ten dollars, within twenty-four hours thereafter, shall make a written report of the circumstances thereof to the Commissioner of Motor Vehicles and shall supplement such report by a detailed statement, under oath, on blanks to be provided by the Commissioner, which shali be as nearly accurate as may be ascertained and shall state the time, place and eause of such accident, the injuries occasioned thereby and such further facts as the Commissioner may re- quire. The Commissioner may make such investigation of such accident as shall seem to him advisable, and for such purpose he may require the assistance of the state fatal accidents. The numbers that represent the accidents occurring at each point are on pins, those up to five : having triangular heads and those beyond square heads; plain round heads show, independently, it to Hartford. Similar maps are kept for all the large cities of the State A year’s (1923) traffic accidents in New Haven, as tabbed in the office of the Commissioner of Motor Vehicles for the State fill out. If you don’t report, the other party to the smash probably will; and then your goose is cooked. For it takes two reports to complete the Commissioner’s file on an accident, and if the second isn’t forthcoming, he goes out and gets it! The police and the casual witnesses afford another means of checking up; and one of the young ladies in the Commissioner’s office clips a large number of accidents from the papers of the State, and every once in so often a failure to report is uncovered in this way. The probabilities of your getting away without reporting, in the end, are very slight; and of course a late report or a reluctant one is a bad one upon which to rest your defense, not to say a word about the fine. When you get your blank, you are confronted with a regular income-tax-return proposition. Under the head of general information you are asked for the complete address and exact location of the accident. You are asked to choose between ice, wet, good, snow, rough, mud, and sand as characterizing the condition of the road surface at the time; between straight, curve, up- hill, downhill and intersection as describing the shape of the road; and between clear, rain, snow and fog as describing the weather. You are asked the date and the hour; and you are given the choice between trolley, travel. Then you sign, swear, and mail Now it is obvious that, from the view- point of fixing civil and criminal liability for this particular accident, there is a big advantage in thus getting a statement of facts upon official record. But from the viewpoint of the Commissioner’s office, such advantages, large as they are, are quite secondary. The thing that makes this reporting of accidents valuable is the complete statistical record which it affords of the accidents that disfigure Connecticut’s highways in the course of the month or the year. This record turns in several direc- tions, and we must follow it a short distance in each of these directions if we are to understand the value of the reporting system in preventing accidents. For one thing; you will recall that the parties to an accident must report the years in which their machines were manufactured. As a result of this, Commissioner Stoeckel is able to state categorically that old automo- biles are more frequently involved in accidents than new ones; and the older, the more frequently. This at once suggests that the new driver is not responsible for so large a proportion of our automobing woes as we have ordinarily supposed; and that we may go too far in harassing him in his efforts to learn. More important than that, it suggests to Commissioner Stoeckel that he will ultimately have to ask authority from his legisla- ture to inspect cars, and to rule off the roads those which are in such condition as to jeopardize other (Continued on page 360)

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May, 1924 SCIENTIFIC AMERICAN Our Abrams Investigation—VIII The Report of a Test on Localization of Abscessed Teeth Through Handwriting Secretary to the SCIENTIFIC AMERICAN Abrams Investigation Committee NE of the numerous startling claims made for the so-called electronic technique is the ability to “localize” diseased condi- tions. That is to say, given a drop of blood or even a specimen of handwriting, the skilled electronic diagnostician should be able to tell not only the cause of the patient's run- down condition, but also the point in his anatomy that is affected. Thus it is by no means By Austin C. Lescarboura tronic equipment is based. BUT— Abrams, we are as- sured, was crude. He lacked scientific training. True, he was a great doctor, but when he made these start- ling scientific discoveries he did not have the necessary scientific training to work them out to the necessary polished state of the present products which you are now beholding. These products are scientifically cor- rect; they work with the utmost precision; they are a vast improvement over the crude uncommon for an electronic diagnosis to include some statement as to the locali- zation of a pathological condition; there may be a specific reference to a certain abscessed tooth, an infected tonsil, a certain cancerous growth, a_ spotted lung, a marked syphilitic outbreak at a definite spot on the skin, and so on. Many are the stories told of wonderful localization of various diseases by means of blood and handwriting specimens; and, if anything, E. R. A. places more reliance on its ability to localize than it does in the high accuracy claimed for its general diagnosis. Abrams apparatus, so we are told. There are today some fifty brands of electronic equipment aside from the simon-pure Abrams apparatus. The genuine E. R. A. men using genuine E. R. A. equipment will tell you that all other brands of equipment are to be taken with a grain of salt. The genuine apparatus of Abrams has many secrets locked up in its admittedly crude cases, and therefore works where others fail. Any test which this Committee under- takes with a non-E. R. A. man using non-E. R. A. apparatus is immediately repudiated by the dyed-in-the-wool E. R. Here again it becomes necessary for the Scientific American Abrams Investi- gntion Committee to seek first-hand proof as the result of tests. Were we to take the testimonials of E. R. A. at their face value, we should be obliged to admit the condemnatory statements of those who have already investigated certain phases of electronic work. Obvi- ously, it would not be fair nor scientifically correct to admit one side of the evidence without admitting the other. Time and again we have been asked by E. R. A. to accept their evidence at its face value, and time and again we have offered to publish their Radiograph extraction teeth of our case B, after A. men. Take the other side of the pic- ture: the non-E. R. A. men using non- E. R. A. equipment will tell you that the genuine EF. R. A. workers are relatively crude and are working with hopelessly inaccurate apparatus. Therefore, any test made with a genuine E. R. A. worker using genuine E. R. A. equip- ment is immediately repudiated by the non-E. R. A. group. And to make the matter still more humorous— if there can be any humor in this huge movement which has enrolled upwards of four thousand doctors through- out the country—any E. R. A. worker who submits to of infected of a tooth employed in any of our tests now or in the future, the essential phenomenon is nevertheless under test just as much as if we were working with a genuine bk. R. A, outfit. It appears that the non-E. R. A. group have been taking keen delight in the fact that so far we have received no tangible co-operation from the genuine EE. R. A. camp. Indeed, the non-E. R. A. group of late have put forth the claim that the reason why no con clusive E. R. A. demonstrations were forthcoming was because the E. R. A. apparatus was defective. In fair- ness to BE. R. A. let it be said here that every demon- stration we have witnessed with the use of non-E. R. A. apparatus, no matter how elaborate that apparatus may be, has failed to prove the validity of the basic claims. All the electronic workers are pretty much in the same boat so far as their ability to prove anything is con cerned — at least up till this writing. All of which is rather off the main track of this particular report on the progress of our Abrams inves- tigation. However, it is quite necessary to settle, at this time, this question of genuine and independent electronic workers and their apparatus. Some time ago a well-known gentleman in Los Ange- les, who has taken a keen interest in the Abrams con troversy, suggested that we make a test with a doctor connected with a Pacific Coast electronic laboratory, for the purpose of testing the remarkable aceuracy of electronic localization. Through this gentleman’s kind offices we submitted two specimens of handwriting as directed, these specimens representing two dental cases with clearly defined abscessed teeth. The electronic worker was to identify the abscessed teeth by means of the handwriting specimens. And so we have the elec- tronist’s report of his findings, as well as the report of the dentist, Dr. Mitchell of the Bronx. who co-operated with us in the selection and prepara- side of the story on the condition that tion of the cases for the electronic each and every bit of their evidence be subjected to proper examination, and that we be permitted to publish evidence supplied by parties who have investi- gated and who are now quite obviously antagonistic to the progress of E. R. A. And so we arrive once more at the con- clusion that the best evidence is that which this impartial committee can gather through its own efforts, and over which it has absolute scientific control so as to have its findings based on cold facts rather than mere hearsay and highly colored claims. So in the matter of localization, we have sought a test with a competent the donor’s state of health? OES a drop of blood give off emanations by which it is possible to diagnose Can the same thing be done with a specimen of handwriting? Is it possible to carry out the most accurate kind of diag- a nostic work with a collection of pseudo-electrical apparatus of the crudest kind, together with a blood specimen and a human “‘detector” or “‘reagent’’? Is it true that numerous cases given up as hopeless by orthodox physicians, have been cured with a machine known as the oscilloclast, which is claimed to give off some form of energy that cannot be detected by normal physical or electrical means ? are some phases of the Electronic Reactions of Abrams technique which the SCIENTIFIC AMERICAN set out to investigate. investigation have appeared in every issue of this journal, beginning with the Octo- ber, 1923, issue. The reader is referred to the back numbers in order that the pres- ent report can be clearly understood.—THE EDITOR. examination. The first patient was our case A. He came to the dentist's office with badly infected tooth. Orthodox dental examination disciosed an in- fection around the upper right second bicuspid. It may be mentioned here that this tooth is the one immedi- ately ahead of the upper right 6th year molar. Reference to the accom- panying radiograph will clearly indi- These Reports on the progress of this eate the infected area within the circle. The light area, within the arrow-head, tooled in on the engravy- ing for reference purposes, shows the diseased root of the tooth. electronic worker, an E. R. A. worker The second patient was our case if possible, but at any rate a competent “electronist.”. By now it should be clear to those who have followed the progress of this investigation that while there are genunie E. R. A. workers and non- E. R. A. workers, the technique is uniformly based on the same broad principles enunciated by the late Dr. Albert Abrams of San Francisco, the founder of the Electronic Reactions of Abrams school of medicine, known as E. R. A. for the sake of brevity. Whatever may be the impelling motive, the fact remains that many of those who have taken the authorized E. R. A. course of instruction and who have started out with authorized E. R. A. equipment, have in short order gone about devising their own variation of the so-called electronic diagnosing and treating equipment. Always, of course, the claim is made that because of the desire to place electronic technique on a more scientific and stable basis, this particular doctor to whom you happen to be speaking has spent vast sums of money and vast funds of brain power to the end of evolving this par- ticular kind of apparatus. Of course, Abrams is given full credit for the basic discoveries — the radioactive properties of blood; the human reactions in the abdo- men, which are detected by percussing, feeling, or rub- bing the abdomen with a glass or vuleanite rod; the different disease wave-lengths or rates, starting with the famous “57” of pickle fame; the treatment of elec- tronic disease findings by means of similar waves or rates, working on the homeopathic theory that like eures like. Always — always, please remember in the future — Abrams is the foundation on which the elec- an official test is immediately disowned on the various grounds that he is incompetent, that he is not using the very latest technique, that his equipment is of an ancient vintage famed for its inaccuracy, and so on. And so it goes, An investigator soon begins to wonder whether it is possible to get together a genuine E. R. A. worker, equipped with a genuine, accurately B, who also reported to the dental office with a badly swollen face due to an infected tooth. Orthodox dental examination disclosed infec- tions in the right central and upper left lateral teeth, the infection of the latter being deep-seated and necessitating considerable treatment and drainage. The circle in the radiogram of this patient shows the infected area after the extraction of the upper left lateral tooth. calibrated E. R. A. outfit, working with a genuine subject or reagent, provided with specimens of blood or handwriting which have not been tainted somehow, and with generally favorable conditions, such as a non- antagonistic frame of mind on the part of the investigators, so as not to upset the delicate reactions. However all that may be, the fact remains that the technique is always Hence in both these cases we had clearly defined abscessed conditions, which were sufficiently developed to make them identifiable beyond the shadow of a doubt by any means which lay claim to even a modest de gree of accuracy. We were assured beforehand that the electronic worker in this case, as well as his electronic laboratory, scored very. high in this kind of work; hence we looked for- the same. The basic principles are the same. The reactions, on which the entire electronic structure rests, are the same. Quoting from a letter from Dr. Jean du Plessis, head of the Chicago College of Electronic iiedicine and one of the leading E. R. A. workers, “You are of course aware of the fact that the type of apparatus makes mighty little difference in proving the existence of the essential phenomenon.” So, here we can put down on record, once and for all, that no matter what particular brand of apparatus is Radiograph of infected teeth of our case A ward to a clean-cut success in both these cases, if electronic localization was to be taken seriously. In due course we received a letter from the Los Angeles gentleman, stating in part: “I am herewith enclosing memorandum of the two teeth which Dr. ————— thinks he has located as being abscessed according to the handwriting you have sent on to me. Dr. made this diagnosis with a machine constructed especially for himself and he (Continued on page 361)

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TT: seetion across the grain. RR: radial surface (“quarter- sawed” or “‘edge-grain’’). TG: surface tangential or parallel to the annual rings (“‘flat-crain’’) NWR: medullary rays. V: ves- sels. F': wood fibers. S, SM: “springwood” and “summerwood” portions of the ring P: pits. SC gratings at longitudinal junctions of vessels Fig. 1. Highly magnified view of a block of hard- wood, showing its cellular structure, from a drawing by the author based upon actual micro-sections S|OES painting actually preserve wood? And if so, how? The question is not so simple as it seems. Ask the timber path- ologist, and the answer is that there is nothing in ordinary paint which is poison- ous to fungi and therefore it does not antiseptic action. prevent decay by any SCIENTIFIC AMERICAN May, 1924 Does Paint Preserve Wood? A Conflict Between Theory and Practice, and How It Is Explained Away By H. D. Tiemann Dry Kiln Expert, U. S. Forest dries will need explanation. Perhaps the most impor- tant of these is the peculiar propensity of wood to become “set” or fixed in the position and dimensions in which it is held while it dries. While wet, and par- ticularly when. warm, it is somewhat plastic and may be distorted to a certain extent by applied forces. If the forces are applied continuously during the drying, the wood will harden and retain the distortion even after the forces are removed. This statement applies not only to the piece as a whole, but also and more especially to the internal structure. Suppose a piece of wood which has been thoroughly moistened is prevented by framing or brac- ing from shrinking until it is dry; it will become “set” in its expanded condition, and will remain enlarged after the bracing has been removed. The internal stresses set up at the start seem to have disappeared entirely. But they have only become latent, as it were; and if the wood is remoistened they will again reappear in full force and effect. For example, if a piece of bentwood be remoistened it will tend to straighten out, particularly if heated. The hardening process is thus quite a different thing from the hardening of cement, where the stresses do not thus become latent, and it should not be thought of in the same way. The actual internal mechanism of wood behavior un- der moisture changes is unknown; but in order to pic- ture what will occur in wood under given circum- stances the following analogy may help. Imagine a honeycomb in which the cell walls are composed of a substance which is plastic and somewhat elastic, like rubber, when wet, but loses these properties when dry, hardening in whatever shape it is held while drying. Furthermore, suppose that the substance itself swells Products Laboratory, Madison, Wis. may be produced by stretching the block originally. Now, to come closer to the main point, let us suppose that we start with a dry block of this honeycomb and clamp it in such a way that it is impossible for it to swell (just like honeycomb in its square wooden frame), but that we exert no external compressive force upon it other than the resistance to its own swelling. Now let it be moistened, and what will hap- pen? The cell walls will swell, but as the block as a whole cannot expand, the walls of the cells will crumple, distorting the form of the cavities. If now the sub- stance be dried it will harden in the new crumpled shape, the stresses becoming latent exactly as in the other case. The cell wall substance will then shrink as before and the whole block will pull away from the box, and it will now occupy a smaller space than it did originally before it was moistened. Upon remoistening in a free condition the crumpled walls will resume their elasticity and tend to return to their original shapes. Fig. 1, which is a drawing of a grain of hardwood sawdust highly magnified, shows that our honeycomb analogy for wood structure is not so very far from actuality. Coming now to the actual drying of a piece of wood, the sequence is this: The outer surface, drying first, tends to shrink but is prevented from doing so by the moist interior. Stress is set up, the outside in tension, the inside in compres- sion. The outside then becomes set (“casehardened” ) in its expanded condition, as explained in the analogy. As soon as the free water has all evaporated from the cavities of the interior cells (“fiber saturation point” passed), the inside of the block tends to shrink but is in turn hindered from doing so by the expanded set exterior. The stresses are therefore re- So far as known, decay occurs and can through the action of fungi. He will say, furthermore, that paint may only oecur even induce rapid decay by keeping the wood damp on the inside, retarding its rapid drying when placed in a situation where it frequently is subject to wetting in other words, introducing a factor of lag in the wet-dry cycle The wood technologist, moreover, will tell you that paint does not prevent the PRS TETE A PU RE TT TP IT” “TO Tey me we ees “ ld he be | aT ‘ m © RE ewe LOTTE Theo ec versed, the inside now being in tension. As drying proceeds still further the inside set” in an expanded condition which, owing to a slight yielding of the exterior, will be of a less degree than the set of the latter, or else the tension will become so great that the fibers will actu- ally pull apart, causing what is commonly designated as “honeycombing” or “hollow horning.” These stresses are easily proved by cut- becomes absorption of moisture from the air. While undoubtedly a retardant, it does not act as a moisture-proof seal; and Fig. 2. nothing but hermetically sealing up the wood will prevent its ultimately absorbing moisture if exposed to a damp condition long enough. Some forms of varnish are better in this respect, shellac is good, and paraffin is better still. Three coats of spar varnish may postpone the final action for a month or two, but linseed oil paint, even in heavy coatings, will only delay the evil a few weeks. Consequently the “working” of wood — its shrinkage and swelling with exposure to dry and to damp air for considerable lengths of time — cannot be prevented by painting or varnishing. This phenomenon is orly too familiar to every householder as well as woodworker through the shrinkage and swelling of floors, doors, picture frames, and furniture. In heated rooms in winter the moisture content will drop to four or five per cent of the dry weight, and in summer, with outdoor conditions in the house, it will rise to 12 or 14 per cent or may even reach 18 or 20, with attendant sticking of drawers and rubbing of doors, Now suppose you go to the builder or the practical man in general and ask him about this matter of paint. His verdict, based on vears of experience, will of course be that.painting is highly beneficial in protecting the wood. Are the technical men wrong? Or can we somehow reconcile these apparently conflicting ideas? The answer lies in the behavior of wood to the influence of not generally understood true, and it is interesting to follow out the way in which moisture, a manner of behavior which is All the statements made are paint actually does prevent or retard the destruction of wood, We need not appreciate paint less for know- ing wood better Some of the phenomena which take place when wood Section of a two-inch walnut plank cut into prongs to stresses which occur internally during drying and shrinks with moisture changes. Suppose we take a wet block of this honeycomb and compress it by an external applied force. The result will be that the cells will become distorted; instead of being hexagonal they will become more elliptical in outline. Now let the substance be dried while being held in this distorted ting a cross-section from a dried block and slicing it into prongs like a fork. The unbalanced stresses cause the prongs to curve, the tension side being concave and the compression convex. By an indirect method the set condition is also easy to show. If the section be sliced into prongs when only half dry and then allowed to dry slowly in the air, the outer prongs will shrink much less than the show the condition. The walls will at first stiffen up and lose their elasticity so that there is no longer any tendency for the cells to resume their hexagonal form, the stresses thus disappearing or becom- ing latent. This is an ex- planation, or a fairly good picture at least, of the “set- ting” of wood in a distorted shape or size when it dries. At this stage a further im- portant effect of drying will occur; the same process will be noted when we come to the actual phenomena of wood. The wall-substance it- self, according to our hy- pothesis, will begin to shrink, and the result will be that the block as a whole will finally reach a smaller size than it would have done had no compression been applied to start with. (A _ similar result of the opposite kind C: piece in original air-dry condition. A and B: steamed and redried: A: prevented from swell- ing by a clamp; B free. Note the end checks on B due to the restriction on swelling imposed by the rest of the board Fig. 3. Oak board showing the result of prevented swelling when moistened — Sateen

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May, 1924 inner ones, owing to their already set condition. This is clearly shown in Fig. 2, which is a section of a walnut plank treated in the manner just described. The internal stress which would have existed had dry- ing been completed before the slices were made is ap- proximately measured by the force which would be re- quired to bring all the prongs to the same length. This is evidently considerable. Can you wonder at a piece of lumber for cracking open or warping under such stresses? Yet this condition is not the exception, but the general rule. In fact, it is practically impossible to dry a piece of wood wihout such stresses occurring to a greater or less degree. If there is doubt about this in the mind of anyone, let him make the test himself. It is very easy. The section should be cut while the board is still damp inside, as explained above. We are now able to predict what is likely to happen to a piece of wood exposed to the weather. If a dry piece of wood is held or clamped in such a way that it cannot swell and it is then moistened, a strong com- pression stress will be set up by the wood itself in itself, which will act in the same manner as an applied external force. If the wood is redried under this re- striction it will become “set in compression” to such an extent that when it finally reaches its original state of dryness it will be smaller than it was before. By repeating this process a piece of wood may be made smaller and smaller. By the method of repeated wet- ting under restriction and then redrying, a strip of air-dry basswood 9-15/16 inches long tangentially to the rings was compressed to a length of 7-7/16 inches, Fig. 3 shows a one-inch oak board from SCIENTIFIC AMERICAN A: normal. B and C: soaked and redried, C having been clamped while drying and B free. All three thoroughly dried Fig. 4. Experiment showing how wood may become set in expanding condition grain board. The length of the strip is tangential to the rings. A, which is ten inches long, was retained in its air-dry state. B and C were soaked in hot water, C being then clamped between two strips of per- forated iron. All three were then thoroughly dried at 200 degrees Fahrenheit. The piece C, held in the clamp during drying, could not shrink appreciably and became “set” in this expanded condition, in which it graph. Now these cracks were not wetting and drying alone, but by the compression stress caused by the restriction to swelling, the subsequent setting of the substance under compression, and further shrinkage as it redried. Repeated wetting and drying causes an accentuation of this condition It is this rroduced by the identical process which causes exposed surfaces of wood everywhere to crack open and become weathered (ne frequently observes its results in hard- which the smaller end section was first eut off and the larger piece cut in two. One-half of the larger piece (marked A) was then clamped in an iron frame so that it could not expand tangentially, was steamed about a day, and was subse- quently allowed to dry again. It soon became loose from the clamps and finally shrank to the size shown in the photo- graph. The other half, B, received pre- cisely the same treatment as A except that it was not held in the clamp while being stenmed and was free to swell as much as it pleased. Notice, also, that the ends of the piece which was not clamped are very much checked. This is not an accident, but is due to the same cause. Since the wood takes on moisture much more rapidly at the ends than in the mid- die, the ends tend to swell; they are pre- vented from so doing, however, by the middle portion of the block. The ends are therefore thrown into strong compressive stress, just as the clamped block was, and when the block is dried they will, in the characteristic manner, shrink more than the rest of the block, thus opening up in wide end-checks. wood window and door sills, flooring and steps, which are subjected to repeated wetting and drying. As dirt enters the cracks the compression is thereby in- creased each time the surface swells; when it dries, the openings become wider and the cracks strike in deeper and deeper. It will be observed that at first it is only a surface effect and is due to the prevention of the swelling of the surface by the deeper portion of the wood which has not yet become wet. It is the abrupt changes in moisture content between the surface and the inner layers of the wood, or between any adjacent portions, which are responsible for the conditions of sur- face ghecking and subsequent deteriora tion. Paint is not proof against gradual ab- sorption of moisture and therefore will not prevent swelling or shrinkage from taking place if given suflicient time; what it does do is to retard the rate of absorp tion or loss of moisture through the sur- face, thus giving time for a partial zation of the moisture and reduction of the moisture gradient within the piece. Paint does not make wood poisonous to equali This is not merely an interesting labora- tory experiment of purely “scientific in- terest”: not by any means. It is one of the most fundamental facts concerning the behavior of wood and applies all the way from the lumberman’s shanty to the finest piece of furniture in the lumber king's palace; but it is not commonly under- stood. The reverse of this action may also be brought about, as in the casehardening of the outer surface of wood, illustrated in Fig. 2. In Fig. 4 are shown three strips of basswood, all cut adjacently from an air-dry flat- Fig. 5. Section of oak, showing compression checks produced by wetting and redrying a small portion now remains indefinitely after removal of the clamp and will so remain until it is soaked again. But what has all this to do with paint? Let us see. In Fig. 5 is shown the cross section of a well dried piece of red oak which showed no checks. The central area was then wet several times with hot water, care being taken not to wet the surrounding portion. Upon redrying, the cracks appeared as seen in the photo- Fig. 6. The checked portion here was unpainted, and subjected to repeated wetting and drying wood-destroying fungi, but by preventing the surface cracks it makes it harder for the fungi to get a foothold and so helps to preserve the wood. The equalization of the moisture distribution through out the piece brought about by the coating of paint when applied to all surfaces, aiso prevents excessive warping of the piece as a whole. Fig. 6 shows an oak board which has become’ consid erably cracked in the central portion. This board, a flushtank cover, was subject to repeated wettings and dryings. ‘The surrounding portion which is not cracked was protected by a coating of paint and oil, whereas the coating had entirely worn off the central portion. The explanation has been suggested, and the result speaks for itself. A New Trade, the Straightener? F Ape piceonper nye suggests that there is one line of repair work that is practically untouched so far as specialization is concerned, yet is peculiarly adapted to segregation and placing in a one- or two-man shop. There is a never-ending volume of straightening to be done, and it can be made to pay much better than or- dinary repairs. The “straightening shop” is badly needed in the automobile repair business and the ma- chinist of ability in that line will be received with open arms. The wear and tear of every-day running, the uncorrected loosenesses, clean breaks, little accidents of driving, and all the happenings included under the name of “wrecks” serve to feed the job list of the straightening shop. An expenditure for equipment that would put in only the gas tank and pump of a garage or would but poorly equip another specialty shop, will fit up the place in first-class shape for straightening work of every conceivable description.

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316 SCIENTIFIC AMERICAN May, 1924 Exploring Within the Steel How Magnetic Analysis Indicates the Presence of Flaws in Rails and Beams and Hoisting Cables ET us imagine that there is a hidden trans- verse fissure in the center of a steel rail, but you do not know it is there. That rail will later be laid down as a part of a railway track and some coid night,

when the ste tleness, there will he ‘| is chilled to increased brit- a complete fracture followed, per- haps, by a disastrous wreck, That thing has happened many times until been no sure way to presence of hidden defects in the in there the because has recently discover the By A. G. Ingalls investigation of the general problem of the relation be- tween the magnetic and the mechanical properties of steel. During that year Dr. Burrows was carrying on an important magnetic research in cooperation with eral foreign magnetic specialists of note. The investi- gation required two short steel bars of identical mag- netic properties. This seemed to be a simple require- Sev- ment but it soon became evident that two bars one- half inch in diameter and ten inches long, having identical magnetic properties do not exist. They cannot and of the War Department as well as of leading uni- versities and several additional industries which had taken up magnetic analysis during the year, were added to the special magnetic analysis committee of the Ameri- can Society for Testing Materials. This Philadelphia society is very largely responsible for our present knowledge of the materials of engineer- ing and for the standardization of specifications and method of testing. Formed in 1902, it has a very large membership among the engineering and allied profes- sions, and it has kept in existence forty

terior of a steel, true of all piece of The same is not only trans slag inclusions and hard But a method for finding impertections kinds of flaws, verse fissures but or soft spots, such has been discovered and recently put to work, and that method happily the output of a steel mill or factory to be investigated just permits entire as rapidiy as it is produced. Magnetic what the name suggests. It analysis is,,in general, just takes advan various magnetic properties of tage of the steel and iron, and it permits of the mak-

standing committees with a total member ship of about 1400 for the purpose of studying the properties of materials of engineering and developing standard specifications, methods of testing, defini- tions and recommended practice. Its activ- ities are intimately woven into our whole industrial fabric. Naturally its work is known to a lesser degree outside of the engineering profession than within it, because it is of such a nature that it does not often penetrate through the fun- damental layer of the constructional world formed by that profession. But its work nevertheless stands underneath the whole structure.

ing of many more deductions regarding the inside of given piece of magnetiz- able metal than would at first glance seem apparent. So successfully have these deductions tallied up with the facts that the new met of testing steel has been

put on a working commercial basis peep into the nature of magnetic which To give a brief analysis before turning to the considerations naturally lead up to the exposition of its methods in detail, Dr. C. W. Burrows, the pioneer in the field of magnetic analysis research, and inventor of the equip- ment that is being used for the analysis, has said, “There is one, and only one, set of mechanical char- acteristics corresponding to a given set of magnetic and conversely there is one, and only characteristics corresponding to a characteristics ; one, set of magnet given set of mechanical characteristics.” Add to this statement the fact that magnetic analysis makes use of all the several magnetic qualities of steel and iron, particularly of induction, coercive force, resid- ual induction, hysteresis and the various per- meabilities, as certain combinations of these qualities; and that it employs two types or phases of mugnetic i energy well as apparatus known respectively as the defecto- and you rough of the question that nearly everyone scope and the magnetoscope, have a general statement asks when first confronted with something new. That is, “How does it work: and why?” Refore taking up in detail how it works and why, two significant considerations must be gone into. If ground for an understanding of ms been commercialized today, we are to get a back “magnetic analysis as i we must know a little about The rod is carried through the solenoid by means of two rolls driven by a small control box, galvanometer and recording device are not shown A laboratory form of rod defectoscope be made. Many thousands of dollars was spent on a fruitless search, while specialists and experts were unable to give any help. Then special furnaces for the preparation of the desired pieces of steel were prepared, while the rolling and annealing were given that would make a royal babe seem neglected. And still the resulting bars, prepared as carefully as modern science could prepare them, showed magnetic differences. This extreme sensitivity of, the magnetic test of bars having identical properties when measured by other methods of testing, whether chemical or physical, seemed highly worthy of further investigation, and the knowledge gained from the subsequent research has turned out to be of vastly greater value than would have been a successful conclusion of the original piece of research. Four years later the Pennsylvania Railroad began an independent investigation of magnetic analysis, which was combined, one year later, with that of the Bureau of Standards. This joint investigation con- tinued at Washington for six years, during which period the value of the new method of analysis as an aid to technical research was clearly demonstrated. In 1918 the American Society for Testing Materials, of Philadelphia, appointed a committee on magnetic steel a care motor. The The great and fundamental importance of testing the materials of construction cannot be overestimated. Not only money and things, but life, depends upon it. Take the case of railway rails. There you have a com- paratively concentrated mass of iron and steel, the loco- motive, weighing up to nearly a million pounds thunder- ing over a pair of steel ribbons that must be free from flaws if they are to withstand the stresses they are subjected to by such great weights in motion. Our railroads buy two million tons of steel rails every year. The great automotive industry uses another three and one-half million tons. Another five million tons go into buildings, bridges and other structural work. All of these things have direct connection with the safety of human lives. This fact furnishes one of the chief reasons why steel must be tested before it is used. Users of steel usually refuse to buy an ounce of it unless they know Yet none its composition accurately. of that which they buy and use has been tested. Here is a paradox! When we state that a given lot of steel has been tested and the analysis returned we mean simply that One hundred tons of steel is made, poured into ingot molds, rolled out and a few Even at best it is a case of testing one piece out of a dozen, or a hundred, and gambling on the hope that the remainder are like this piece which has been destroyed in the process of testing. This is essentially samples of it were tested. pieces chosen at random for tests,

and who has been behind its development. who began it Such knowledge gives a yportion to those sense OL pre have not found it keep in the salient de- who pos sible to infimate contact with velopments of the steel in- dustry We must also try to grasp the great bnper- tunce of the testing of the als of construction,

a hit or miss method, but until the development of magnetic analysis it was the best method known. Not only is the method of basing the quality of a batch or lot of steel on tests and analysis of mere samples fraught with the ever-pres- ent danger that luck may play strange tricks with the choice of samples, but it

and briefly review the tests involves the destruction of that have been used by in- these samples. In order to dustry in an effort to know test the tramsverse strength the nature of the steel and ot niger : “mr . of a structural steel shape iron used The instrument board supports a collection of ammeters and voltmeters, an A. C. indicator and a heavily damped D’Arsonval you must |! 1 it t 0 Fe : : . . nus as atin “ail use of magnetic analysis, a considerable saving to the manufacturer was effected s encouragement of great rail- analysis of a sample you ways, and great manufactur- ing industries. Much of the fundamental work was accomplished in the United States Bureau of Standards, at Washington. Numer- ous university professors of physics and engineering have also collaborated in its investigation. In 1906, Dr. C. W. Burrows, who was in charge of the Magnetic Section of the Bureau of Standards, began an A corner of the Burrows magnetic laboratory analysis, consisting of research engineers from the tool, ball-bearing and rifle industries, together with a rep- resentative of the New York Central Railroad, and sev- eral professors of physics and engineering, all cooperat- ing under the Chairmanship of Dr. C. W. Burrows. In 1919, representatives of the National Research Council, must ruin it. If you wish to examine it under the micro- scope you must cut it up into very thin sections. The piece you test is never the same piece you are to use. It is one of a lot, and your faith must make up for the uncertainty involved thereby. In the early days the judgment of the workman was the chief criterion of steel quality. He looked at

Page 17

May, 1924 the grain of a freshly broken piece, judging it by a “blow of the eye.” Then there was the cold bend test in which he bent a piece flat on itself and examined the stretched fibers, or he broke a piece of the steel and “read his carbon by fracture.” Later tests largely eliminated the human factor. The tensile test is made in a powerful machine which tears the test piece in two, giving a record of its strength. This is necessarily a destructive test. test, where the test piece is crushed, is likewise a de- structive test. The bend test is of a similar nature. One very important test is that for determining the hardness of steel. The scleroscope, which is sometimes used for this purpose, makes use of a little steel hammer having a slightly spherical striking point, two hun- dredths of an inch in diameter. This is dropped a dis tunce of ten inches on the test piece, making an inden- tation and rebounding to a measurable height. The impact corresponds to a pressure of several hundred thousand pounds per square inch, and the hardness of the sample is measured by the amount of rebound. A second test of hardness is called the Rockwell test while a third method which is very widely used is the Brinell test. Here a hardened steel ball is forced into the metal, making a tiny concavity. The maximum pressure applied, divided by the area of the concavity, gives an arbitrary “Brinell number,” or hardness num- ber. This test is non-destructive, but it tells nothing further than the surface hardness of the steel. Hidden flaws are not found by it. Chemical analysis is one of the methods used for learning the facts steel. A _ well-equipped chemical part of all modern. steel plants. only and it The compression important batch of forms a most about a laboratory But it likewise applies runks as a to samples; also SCIENTIFIC AMERICAN Ww po. ~] X-ray apparatus is able to make clear and _= distinct photographs through a thick- ness of one inch of steel in one minute. But a two-inch thickness requires five min- utes; while three inches, the present limit, consumes thirty minutes. Greater thickness than this may be “seen through” by magnetic analysis almost instanta- neously, permitting . long, heavy products to be moved along at a lively rate of speed while they are exam- ined. The fact that the rel- atively slow X-ray study of steel has exposed many previously unsuspected de- fects, such as forging and shrinkage cracks, shrinkage cavities or porous spots and burnt metal favors the use of the far faster magnetic analysis for the same pur- iiinaa 3 : : inalysis 1 7 ta This equipment is designed to test pose. bearings, ete. It determines It must be made clear physical structure after heat treating. that magnetic analysis is means of a polyphase current, not intended as a_ substi- tute for all of the forging methods of testing steel. Rather, it complements them. In addition to telling us by newer methods things we can already find out by defects in hall and roller carburizing, all circular parts, such as pinions, races for machine parts, depth of case The magnetic field is revolved either while the average nature of the piece is tatively after and mechanically or by determined quanti- Analyzer for testing round specimens slowly moving photographic film. Sometimes a colored light is flashed or a bell is rung te indicate that a defect has been located, chemical invaluable destructive test. lLlowever, analysis will always remain an aid to the steel maker. Metallography is a method of examin- ing sections of steel or other metal under The magnetic properties of determined by its past Every detail of its chemical its course of manufacture, ment, and the piece of steel are history constitution, its heat treat which it stresses to has the microscope. Sections about one-half been subjected have united to determine inch square are ground down to a fine its magnetic nature. For steel of a given polish and examined microscopically ; history there is only one set of magneti: then they are deeply etched in order to characteristics. Taking full advaniage of show the crystalline structure. Says Pro- this fact, there are two phases of the fessor Bradley Stoughten of Lehigh Uni magnetic analysis those employing the versity, “In the United States, practically instruments known respectively as the de every large steel works is well equipped fectoscope and the magnetescope. for the microscopic analysis of its prod- The defectoscope analyzes long speci uct. Although only a little more than mens such as rails, pipe, beams, wire, 25 years have elapsed since the first art shafting, rods and cables for flaws such received attention, it has advanced so far as concealed fissures, blowholes, segre as to have become by now another and Left: This form of defectoscope may be kept permanently mounted in shaftways for periodical gations, local hard spots and inhomo very serviceable tool in the hands of the tests of stranded cables. The control and recording apparatus are located at a distance. Right: geneities. It determines whether non expert. tut,” continues Prof. Stoughten, Instead of moving the rails through the solenoid as is done in commercial installation, the rail uniformities exist, but does not indicate “reputations have more than once suffered here remains stationary while the solenoid is caused to traverse its length by means of a whether the specimen as a whole is hard severely because of erroneous deductions : er or soft. It employs direct current. The made from miscroscopic evidence.” Solenoid of cable defectoscope in place in elevator shaft, and the laboratory application of this instrument has been The examination for homogeneity of form of defectoscope developed quite fully. iron and steel by means of the X-rays is becoming common. Yet it is so slow that it can be applied only to thin work or to suspected places. At the Watertown Arsenal a very expensive 300,000-volt the ones that have been in use, it tells us things we have never been able to know. Because its intangible magnetic fingers search within and throughout a piece of solid metal it is able to locate physical defects that cannot be known in any other practical manner. Bet- ter still, these all-permeat- ing magnetic feelers leave no harmful trace of them- selves, When they have passed and done their work the steel remains as sound as before. Magnetic analysis permits the large output of the steel mill or of the factory to be passed in rapid review without the aid of technical experts and without slowing up the process. The exami- nation is sandwiched in with the regular machine-to-ma- chine progress through a factory in such a manner that the steel has merely to be routed through the mag- netic equipment without stopping. If flaws exist in the rails or rods or in any of the long shapes, a record Bucket wheels for steam turbines must be of irreproachable quality and homogeneity. installation a ten-foot disk is being analysed by the defectoscope in a search for blowholes and The disk is slowly revolved while the instrument is steadily moved out- ward from the center, thus covering the whole area in the form of a spiral Magnetic testing apparatus for steam turbine bucket wheels weakening inclusions. is left, either by an auio- matie device which paints the piece opposite the point of defect or by a line which is automatically traced on a In this The other instrument which is employed in magnetic analysis and which is called the magneto scope, analyzes irregular shapes and small parts, as forgings, castings, crankshafts, hooks, and various parts for automobiles and general machinery. Unlike that checks the defectoscope, it is essentially a comparator, in it requires a standard the piece under test. properties such as hardness, grain size, and chemical composition with the standard piece. The magnetoscope uses alternating current, unlike the defec tosecope which uses direct, and the phenomena employed in making the analysis may be either hysteresis energy or magnetic hysteresis. Returning to the defectoscope, this instrument jece against which it ] It compares its general physica! those of con sists of a magnetizing sclenoid and a system of twe exploring coils having the same number of turns These coils are “bucked.” That is, the turns run in opposite directions. The solenoid is energized by direct current and the piece to be tested is passed through from each field as are separated through its interior magnetic well as the two exploring coils which other some inches. Any inhomogeneities in the moving steel will cause magnetic leakage as they pass. That is, the density of the lines of magnetic force set up in the metal will be altered. The changing magnetic flux reacts on the two exploring coils, generating a current in them which is stronger in one than in the other and making itself evident on a sensitive zgalvanometer When using the defectoscope there is in indication of the physical condition of the hardness, grain, size and analysis so properties do not vary too sharply from point to point along the piece under test. So long as it is uniform no indication is given — the spot of light thrown by the galvanometer mirror remains fixed, or, if a (Continued on page 366) general no piece as to long as these photo

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SCIENTIFIC AMERICAN teria” is a serve-self store on wheels capable of serving 400 families per day, with a complete stock of groceries, breads and fruits, green and staple vegetables, meats and drug sundries. It has but one clerk who is also cashier as well as driver. His store is 22 feet long by 714 feet wide, yet so conveniently are the com- cakes, modities arranged, each with its own price tag, and so easy to operate is the overhead-basket carrier device that ten or twelve customers can wait on themselves at one time. If the housewife has babies and no help it is quite impossible for her to go to the store down the street, but here is a well stocked, low-priced “chain store” right at her door where she can get her “items” and be out of the house but a few minutes. That is well enough you say, but these women have May, 1924 The Grocery on Wheels A Self-Service, Motorized Store that Effects Great Economies for Dealer and Customer increased from 3 per cent to 12 per cent even when the retail prices were kept equal to the chain-store prices. Instead of drawing an indifferent trade from a radius of three to five blocks this store visited the families in 35 to 40 blocks every day. Further, it was found that the turnover possible by increasing the number of customers was almost un- heard of in the grocery or meat trade. The turnover of the usual chain store is thirteen times per year, while a ten-cent store turnover averages 24 times. The Mototeria turns its stock 100 times yearly. Daily re- plenishment was found to lighten the load and permitted carrying of a greater variety as well as assuring fresh stocks at all times. The Mototeria carries assorted meats, but mostly cold meats for immediate use, because of lack of cutting facilities. Its meat-order system, however, is a great convenience and saving to both operator and customer. Meats are ordered one day for the next. These are cut exactly as ordered, both as to the particular cut and also as to the weight, in a central, sanitary refrig- erating plant and wrapped and labeled for delivery to the customer. It has been estimated that f meee |t'S A big job that the ladies have to do | 4 | every day. There is being spent today li |} and every day in the United States $49,- | ; 000,000 for food stuffs, by your wife and is _ mine and the 35,000,000 other women who be previde home meais for the tired business men—meaning you and me You could run a mighty big war on that money For each one of the 104 million of us these shoppers spend 45 cents today ind every day. If she does her shopping by phone milady must add 5 per cent to every dollar of your money she spends. Then when the store delivers the order that adds another 10 to 15 per cent to the price for the dealer must charge for this service or lose money on your business. On the other hand, if the housewife goes to the non-delivery or chain store she saves the phone and delivery items, but spends an hour or more, depending on the listance which she must go, to get the groceries and meats, Even though her time has never been valued in dollars and cents—it is, nevertheless, an expense and often an inconvenience to her to spend an hour a day “at the store.” Let us look at i marketing situation from another standpoint It has been carefully estimated that fifteen cents out of every dollar of yours spent for food- an operator with eighty such stores could save $60,000 per year on efficient meat cutting alone, and another $60,000 for truck hire for trucks now used in sup- plying the regular stores. A plate glass “show window” in the rear of the Mototeria provides display of green groceries and fruits. Potatoes and other bulk vegetables are sacked in vary- ing quantities in bins all ready for the cus- tomers. In winter the Mototeria is heated by a novel system utilizing the hot water from the engine. This eliminates the “gas smell” noticeable with the use of exhaust heaters. The store is ventilated by a de vice for that purpose in the roof. It is also planned to have a laundry pick-up with one or two day service in connection with the Mototeria. Large compartments are provided in the body for this purpose. A banking system which stuffs must go towards running expenses ds into overhead. of the store in other wo This is not for wholesaler’s profit, nor transportation—but just for rent, heat, light, clerk hire, hand bills, advertising and waves to the producer, a other necessary expenses. These items, which you pay for when you buy groceries or meats at the store, con- sume one-seventh or a little more of your monthly food bill. These are facts, ft they should be of vital interest to every man and ken from proven statistics; woman. In a typical neighborhood there are five grocery stores—three of them are chain stores. Each one of these stores draws trade from a radius of three to five blocks. The average chain stores sales in large cities are $475 per week and the average net profit is be- tween 2 and 5 per cent ind that 2 per cent plus, is hard to get; it requires scientific management to do it. More than this, few stores turn their stock more than thirteen times per year, and they have to turn it 8% times per year to keep out of the bankruptcy courts. You will wonder that anv of them can make money when we tell vou that there are 457,000 grocers and butchers for the 24,000,000 families in the country—or one tradesman for every 54 families. Is it anything to be surprised over then, that only five grocers out of e hundred succeed in business? Fifteen out of every hundred stagger along the financial edge, barely making living, and eighty out of every hundred last only seven years or less. Yet, fighting against all those odds, and with al! this apparent inefficiency and expensive distribution we do have groceries and good groceries too, and we also have many good business men who have studied the condi tions of the sale and distribution of foodstuffs with the worthy object of making the business less hazardous he proprietors, and increasing the convenience and for lowering the cost to the customers. Taking the store to the customers is not particularly a new idea in itself, but the store on wheels, as con- ceived by L. B. Watson and worked out with the assis- tance of M. L. Pulcher, is a long step towards solving many of these questions. In the first place the “Moto- General appearance of the grocery store on wheels to pay extra for this service, don’t they? Well that is just what Mr. Watson determined to find out. The result was much thinking and a study and planning and a thorough analysis of the field which it was intended to cover. The first unit was built and stocked complete, including everything that a chain store would carry, but having several features borrowed from the old neighborhood shop thrown in by way of good measure. The first unit was put to is done by a stamp and card system has also been worked out by the designers of the new store which has many interesting phases. The taking of coal orders with one day ser- vice is still another plan which may have many eco- Indeed it is well within the probabilities that this system of household service with its many attractive features may revolutionize our whole scheme of food and household necessity distribution, and it is within reason that the bulk of the purchases for the household will be done in future right at the door. nomic sides. work in Detroit last August. To the gratification of Mr. Watson and Mr. Pulcher the shoppers took it up immedi- While they had ap- store ately. preciated the chain with its lower prices, yet they had had to carry the goods some distance which was usually a bother. Here was a which was lighted and heated, neat, clean and sanitary—but best of all with everything need- ed for breakfast, lunch or dinner and with good sav- ings on each item. Natur- ally the women liked it- and the operators were both store surprised and pleased over it. Where the average chain store receipts were under $500 per week the Moto- teria started doing a $1,000 business per week before it had been long on the route. Further, by a reduction in clerk hire, savings in rent, light, heat, window displays, and other items, the profit The man in charge is really a chauffeur-cashier, rather than a clerk ee

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May, 1924 Washington Memorial Bridge at Wilmington To handsome monumental bridge across the his- torical Brandywine Creek in the City of Delaware, herewith illustrated, constitutes a memorial to the Delaware soldiers and sailors of the Nation’s wars, and especially of the World War. Situated in the North central part of the city, this bridge, enhancing the beauty of the natural scenery in a locality that was the theater of stirring events during the war of the Revolution, and which is inseparably associated with the name of General Washington, not only commemo- rates the patriotism of the citizens of the State of Delaware, but also serves to carry the important vehic- ular traftic of the Washington Boulevard. The new bridge is 720 feet long and 72 feet wide and consists of five reinforced concrete arch spans; two 70 feet in length, one 250 feet, and two 85 feet in length; together with the necessary approaches. Each span consists of three arch ribs, 11 feet, 16 feet and 11 feet wide respectively. The deck of the bridge consists of a 40-foot roadway paved with sheet asphalt; two side walks 14 feet, 914 inches in width; and two balustrades or railings 1 foot, 24%4 inches in width. The piers of the bridge are on a 30-degree skew, and the large 250-foot span of 40-foot rise is probably the longest, low-rise, skew arch span in the United States, if not in the world. While the character and design of the entire bridge is of a decided memorial nature, the distinctive me- morial features are embodied in large bronze tablets placed on four monumental pylons or shafts. There are four of these large bronze tablets, all 9 feet high by 5 feet wide, and each with a different inscription. One tablet commemorates the Revolutionary War, one com- memorates the War of 1812, the Mexican, Civil and Spanish-American Wars, and two tablets commemorate the World War, one having the names of the great battles in which Delaware Troops fought, and the other bearing the names of all those service men from the entire State of Delaware who made the supreme sacri- fice in the last Great War. There are eight of the large, ornamental pylons or shafts placed on the bridge in line with the railings. Four of the larger shafts are placed over the piers of the large central arch and two of the smaller shafts at each end of the bridge. The large shafts extend 40 feet above the sidewalk level and the smaller shafts 231% feet. The bronze tablets are placed on the inside faces of the shafts where they can be viewed by pedes- trians on the sidewalks. On the inside faces of the smaller shafts are placed bronze nameplates measuring 3 feet by 4 feet. On each side of the large shafts and on the approach sides of the small shafts SCIENTIFIC AMERICAN City, assisted by Mr. Vance W. Torbet, Architect. Davis informs us that the cost of making a purely utilitarian bridge further serve as a war memorial was, in this case, approximately $56,550, this being less than 8 per cent of the entire cost of the structure. morial bridge daily serving the needs of a community yet at the same time commemorating the unselfish services of these citizens who rallied to the aid of their country View below the 250-foot arch, showing the three massive ribs which carry the floor of the bridge in her hour of need, offers to cities and towns a fitting Human Behavior and Reflexes HE basis of nervous activity is formed by so-called The instincts are complex associations with stimulators—correspond 319 had nothing in common with feeding, is repeated many times with the feeding, after a time it begins to stimnu- late the food reaction when used alone. Thus, if we produce some distinct musical sound at a given rate of frequency of vibration per second—and always at the same time feed a dog, after a while this sound, used alone, will produce the sume food reaction as the food itself. Such stimulators may be formed from any agent of the outer world and with any other instinct. In this way, besides the reflexes or instincts which are inborn, some reflexes are acquired during the life of the individual. The first, or inborn, reflexes we call unconditioned reflexes, and the second, or acquired, reflexes we call conditioned. It is clear that the conditioned reflexes play a very important part in our behavior, as they are being ac- quired during the entire life-time of the individual. Conditioned stimulators serve as si from the unconditioned stimulators, but, like any other signals, they may not signalize properly. Then they ure to be corrected. For instance, in the experiments mentioned, the sound produced by one thousand vibra tions per second was made a conditioned stimulator. If the sound is repeated without the simultaneous feeding of the dog, then for some time the sound loses its stimulating action. But this need not destroy the conditioned reflexes, for sometimes the stimulating ac- tion returns again. Secondly, if the conditioned stimu lator is combined with another agent-——any other agent —and is not at the same time combined with feeding, then the conditioned reflex loses its stimulating action. In both these cases we deal with inhibition In this way the process of inhibition always accompanies the activity of the highest nervous centers. The process of inhibition exists, also, for another end. It helps to differentiate the various stimulations from the outer world. For example, let us form from the sound caused by one thousand vibrations per see- ond a conditioned stimulator for the food reaction, which means that this sound always produces the ordi- nary food reaction or the secretion of saliva. After this secretion reaction is formed te sound all the sounds of the neighboring frequencies, say, 960 vibrations or 1100 vibrations, will also produce als separate this particular the same effect; that is, all the sounds of nearly the same frequency acted as stimulators for food reaction. If, however, we always produce only sounds caused by one thousand vibrations with the feeding of the dog, carefully excluding all the other sounds, after a time all the other sounds will lose their stimulating action and only the one sound will act as a stimulator for the food reaction. It is in this way that the limit of the differentiating ability of the dog or of any are placed large ornamental bronze lan- terns, which are illuminated by a single incandescent Mazda lamp of 250 candle- power. On the inside and outside faces of the large shafts are placed carved On- ondaga Litholite eagles and shields of a monumental character. At the center of the span of the large arch a refuge bay was provided on both sides of the bridge by extending the side- walks slightly beyond the line of the rail- ing, thus forming a vantage point from which pedestrians might pause and view the park below. Refuge bays were also provided at both ends of the bridge. Large ornamental precast stone urns were placed on the end posts of the railing of the refuge bays at the north end of the bridge. The lighting system of the bridge was arranged so as to harmonize with the pylons and railings from an architectural stundpoint, as well as to give the proper lighting effect to the sidewalks and road- way at night. The main lighting system consists of twenty-eight luminous are lights supported by cast-ifon light poles placed on the curb line of the bridge. The secondary lighting system consists of the incandescent Mazda lamps in the other animal may be very easily found, Conditioned reflexes and differentiation make up the whole activity of the nerv- ous system. It is also interesting to point out that recently we have preved that the process of inhibition is exactly the same process as that of sleep. The differen tiating inhibition in sleep is divided into small parts, and sleep is diffused continu- ous inhibition. Thus there is no marked contrast between the normal, active state and the sleepy state.—Abstract from arti cle by Prof. I. P. Pawlow of Petrograd, Science, November 9, 1923 Farmyard Manure and Artificial Fertilizers ; YIR JOHN RUSSELL, in discussing J Agricultural Science as studied at the Rothamsted Experimental Station, said, in a lecture before the Royal Institution on February 9, 1923, concerning the difference between farmyard manure and artificial fertilizers: “Farmyard manure and also plant residues (which are sub- stantially the same thing) decompose in the soil, giving rise to many substances of different types. The plant foods are twelve large bronze lanterns placed on the among the end products; indeed, in nat- ural conditions, and, to a lk extent, in shafts and the two bronze standards at The Washington Memorial bridge at Wilmington, dedicated to the Delaware farms and gardens also, it is in this way the stairway. The two lighting systems soldiers and sailors of the Nation’s wars from the founding of the Republic that plants obtain their food. In usin to the World War are on independent circuits. The bridge was designed to carry the heaviest modern highway traffic, and liberal provision was made for impact and possible future increases in traflic requirements. The assumed loads used in the design were 60-ton electric railway cars placed on the double tracks, a line of 20-ton motor trucks on the roadway at each side of the tracks and a sidewalk load of 100 pounds per square foot. The designs for the bridge were prepared by Mr. senjamin, H. Davis, Consulting Engineer of New York this basis are built time with the action of an instinct, and if the action of For example, food stimulates the food reaction, which consists of some movements of the animal, and secre- But if some indifferent agent, which previously “ artificial manures we supply these end products at once instead of waiting for them to be liberated gradually by the natural decom position. Further, we do not by any means know the whole of the processes whereby plant food is made. But there are certain intermediate products, and it is quite possible that some of these may have a special effect on the growing plant. Curious stimulating effects are produced by substances formed when = soil is steamed, or when oxidation is accelerated by addition of charcoal, and smal! quantities of picric acid.”

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SCIENTIFIC AMERICAN May, 1924 Post-lreaty Standing of the World’s Navies The Urgent Need for Additional Unarmored Craft to Round Out the U. S. Navy see L1E Washington Treaty of Naval Limitation [ i} Vs | will always be regarded as one of the | SAF | me | | greatest works of constructive statesman- | | ship in the world’s history. At a single I : mar £ | stroke, it killed «a vicious and mendacious a propaganda, which was producing that combination of suspicion, fear and hatred whose natural and inevitable child is war. By the terms of the treaty, the United States, Great Britain, Japan, France nd ily agreed to avoid any ruinous competition, und reduce their enormous and cost battleship fleets to ratio of strength of five for the United States, five for Great Britain, three for Japan, 1.7 for France and 1.7 for Italy. Under the treaty, the tonnage allowable for the United States is 18 battleships of 525,850 tons total displacement, for Great stroyers allowed each power should be: United States and Great Britain each 450,000 tons, Japan 270,000 tons. The allowance of submarines was for the United States and Great Britain, each 90,000 tons, and for Japan 54,000 tons. Of aircraft carriers the United States and Great Britain were each ullowed 80,000 tons and Japan 48,000 tons. Because of the fact that Naval aircraft may be readily adapted from special types of commercial aircraft, Congress did not consider that it was practical to prescribe any limit for these. Unfortunately, in the discussions that followed the proposals as to cruisers and other auxiliaries, the re- strictions as to these auxiliary craft were abandoned. On the adjoining page is shown the present unar- mored strength of the Nations that have signed the rather old as vessels go. Japan has 23 ships; France has three, and Italy five. When we come to destroyer leaders, we are hard hit; for we have not a single vessel of this most important class; whereas Great Britain has 18, France seven and Italy eight. In the class of 800 to 1500-ton destroyers, we have a most impressive lead, all of our ships being newly built during the war and showing a speed on trial of 34 to 35 knots. In submarines of 500 to 1000-tons displace- (Continued on page 367) Our Latest Battleship—the “Colorado” HERE are many facts connected with the United States battleship “Colorado” which make her of special interest to the American public. In the first place her displacement of Britain 20 battleships of 32,600 tons (normal) renders DS2.725 tons, (to be early re duced to 18 ships and 525 850 tons) and for Japan 10 world in unarmored ships. buttleships of 318.300 tons All armored ships, both dreadnaughts and preareat naughts, not included in the above totals, were to be de sire ved, us were also all ar mored ships that were being built and were not yet com pleted. Furthermore, no new United States, Great Britain, Japan, France and Italy. destroyers it was proposed that the United States be allowed 450,000 ions, Great Britain 450,000 tons, Japan 270,000 tons and France and Italy proportionately. a were 90,000 tons, 90,000 tons, 54,000 tons and so forth. mored craft were abandoned. 25, HE drawing on the opposite page represents the relative strength of the leading Navies of the No battleships or battle cruisers are shown; the Washington Con- she shares with her two ference having determined a ratio in these ships of 5-5-3-1.7 and 1.7 respectively for the Of light cruisers, flotilla leaders, and In submarines the proposed totals Ultimately, these restrictions on unar- and indeed is so listed by It will be seen that the United States Navy suffers from a very great ' shortage in light cruisers and possesses not a single flotilla leader. her the biggest battleship afloat, a distinction which sister-ships, the “Maryland” and “West Virginia.” The British “Hood” is larger by 9800 tons; but she is more battlecruiser than battleship the British themselves. Not only is the “Colorado” the largest, but she is among battleships were to be built the gnost heavily armed bat for a period of ten years Subsequently, at the urgent request of the Japanese, the battleship“ Mutsu,” as the“Marvland”) which was practically completed, was f about the same size and power permitted to remain on the Japanese lists, on condition that. the United States be permitted to complete two ships of the “Maryland” class, and that Great Britain he allowed to build two battleships up to the limit of 35,000 tons imposed by the treaty. In order that the total limitations of battleship displacement be not ex- ceeded, the three nations were required to destroy cer- fain of their older battleships as soon as these addi- tional ships were complete Most important in its effect on the cost of Naval armament was the reservation regarding the size of future capital ships, which as we have said, was placed ut 35,000 tons. The rapidly increasing size of the battle- ship and battlecruiser, was Naval Treaty. It serves to show at a glance where the United States is strong and where it is weak in the various types of vessels dealt with. The most impor- tant ships are those in the upper half of the page, which are grouped under the caption “first-line ships.” Of equal importance, perhaps, (Admiral Sims and a few others of our Naval officers would say of greater importance) are the ships shown with the caption “air- craft carriers.” The second-line ships, because of their uge, are of minor importance. Frequently during the past twenty years, the ScreNn- TIFIC AMERICAN has urged that our Navy is top-heavy, in so far as we have put our displacement into battle- ships to the neglect of other types. The most serious weakness of our fleet is our shortage of fast light cruisers of S000 tons and over. Unless we include the tleships, since she carries eight 16-inch 45-caliber guns. This is a more powerful battery than that of the “Royal Sovereign” and “Queen Elizabeth” classes, which mount eight 42-caliber 15-inch guns as their main armament. Another point of su- periority is the defensive arrangements of the “Col- orado,” both as regards heavy armor and under-water subdivision. The armor plan includes 13%4-inch side urmor, 18 to 9-inch turret armor, and heavy armor around the bases of the smokestacks. The under-water protection is superb; the hull between the engine rooms and the water being made up of no less than five separate water-tight shells (longitudinal bulkheads) designed to receive the blow of the torpedo and dissi- pate the disruptive power of its gases before they can get through to the engine rooms, the boiler rooms, the inuguzines, or other vitals of the ships. The speed of the “Colo- one of the most alarming f facts of the Naval problem | Under the spur of competi tion each Navy aimed to out build the existing ships of other Navies in speed, power, protection, steaming radius, etc.: with the result that the: displacement had moved up in ten to twelve years’ time from the 20,000 ton “North Dakota” to the 28,000-ton “Queen Eliza beth,” the 82,606-ton “Mary land” and = the 12,000-ton “Hlood,.” Henceforth pre ponderance of power can no ionger be obtained by large increases of displacement The most effective battleship rado” in her recent trials over the official measured mile at Rockland, Maine, Was 21.37 knots. Before un- dergoing these trials, she was sent on a shaking-down trip to Europe, where she at- tracted wide attention and was a subject of very favor- able comment. She is in- deed a very handsome and imposing ship. With her long and lofty spar deck, towering bridge structure, and formidable looking housed-in tops, she presents a truly majestic Naval pie- ture. If we have any criticism to make of the “Colorado” and her sisters, it is that built under the treaty will be the one which combines in the best proportions the various elements of, power ahove enumerated It was the aim of the sponsors for the Naval treaty to make it apply to all classes of fighting craft: but hecause of certain opposition that developed, the limita- tion clauses were not made to extend in any such sweep ing measure to unarmored craft or as they were termed eraft.” In the agreement, the last “auxiliary fighting named were divided under three heads, auxiliary sur face craft, submarines, anti-aircraft carriers and air eraft. Under surface fighting craft are included cruisers exception of battle cruisers), destroyer flo- (with the tilla leaders, destroyers and all other surface types (except existing monitors and unarmored surface craft under 3000 tons) fuel ships, supply ships, tenders, re- pair ships, mine sweepers and merchant vessels readily converted into vessels of war. It was proposed that the total tonnage of cruisers, flotilla leaders and de- inch ; torpedo tubes, 2 submerged Our latest Battleship “Colorado” ten vessels of the “Richmond” class, which, although they were designed to be of 7500 tons displacement have been so greatly increased in armament (50 per cent increase) and in strength of hull, that they displace to- day about 9000 tons—we have no light cruisers of the first class. However, we have put these ten ships in the class of light cruisers of from 3000 to 8000 tons, and this leaves us without any in the 8000 tons plus class, in which the British have six ships, Japan four, France three and Italy two. In the 3000 plus class, we have these ten ships, and it is some consolation to know that in speed and power (each carries 12 six-inch guns) they are incomparably superior to ships of the sume class in other Navies. Great Britain has 35 ships in the 3000 plus class; including many fine and modern vessels; but a considerable proportion of them are Displacement, 32,600 tons. Speed, 21.37. Guns: Eight 16-inch; twelve 5-inch. Armor: Belt, 1314-inch; turrets, 18-inch to 9- too much of their armor is vertical and too little of it horizontal. A few inches taken from the side armor und judiciously placed above the magazines, would render these ships better protected against the steeply falling shells of a long-range bombardment. Similarly a few inches taken from the port plate of the turrets and placed upon the roofs, would render the sixteen- inch guns more secure than they are now against turret penetration. However, all existing ships in any Navy of the world are open to the same criticism. Another interesting fact about the “Colorado,” is the fact that she is the last battleship that we shall build for some years to come, that is to say, until the Wash- ington Treaty Limitation has expired. The limit of size of that treaty is expressed in displacement, and it stands at 35,000 tons. Great Britain, as an offset to our completion of the “Maryland” class, was permitted to build two battleships.

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May, 1924 SCIENTIFIC AMERICAN 321 UNITEDSTATES GREAT BRITAIN JAPAN FRANCE ITALY aa yy 4 " 4 af he. vee: b-,-,*. | Wi) LAE Corti aia 2 — ; S n r a ae rs NE ey . _ 2 ~~ —— 7 - . _—— snes - " €- 2 ES. eee ee? es a O-SHIPS O-TONS” 6 SHIFS 7620 : | PS Ee =e 5 SHIPS 23619 TONS 2 SHIPS "20,000 TONS | LIGHT CRUISERS - ~ B00 TONS + ¥ wid ’ + ; PR ‘ d = afl oa ve ; T) ge =SSHIPS 14,600 TONS *~ SSHIPS 21,000 TONS a OSHIPS. O-TONS sage aN 7 7 i IPS > DESTROYER LEADERS - TONS JSHIPS 16885 TONS BSHIPS I5,SOOTONS | 1500. TONS + j dines wee Fey Pr a oat ang “52 SHIPS 35,658 TONS 41SHIPS 35,5!3 TONS | —e 183 SHIPS og 290 TONS» "Oo arn PS 102 980T ON DESTROYERS ~ 800- 1500 TONS 6 SHIPS 9,692 TONS -* 8 SHIPS 16,200 TONS ; 24SHIPS 30,785 TONS O-SHIPS O-TONS LEET SUBMARINES |}, FIRST LINE SHIPS - eles. ah on ate inden, at Seg es aaa 3 4 SHIPS 24,830 TONS O-SHIPS O-TONS | FC ae 3SHIPS 99,700 TONS 4SHIPS 67300 TONS SSHIPS 96,500 TONS ——_ AIRCRAFT CARRIERS 4 = —epione cars > “ h ° / 1 " aa is oe a + oo’ ee iy = 4 ain te rh | dled : | a Part Ad hs. i PT) Re ee f- @ ; N i Fi) cm ; . tian * “ ond —— a —— = — ~ ~ — — na 8 = = 23 SHIPS~ ~~ 182,625 TONS” 2: Ss 8 1 5E a ONS wie 10 7356 TONS» ~ QSHIPS 56,300 TONS ~¢C RUISERS Mhesih 4 —stah ; pce \ Sige i “2 dae a z ‘ ar) ee : 4) MA Na oe " -—— a —_ — - _— ZISHIPS. 15,562 TONS Ss @ SHIPS 4,200 TONS 12 SHIP. "7,850 TONS: 24 SHIPS 16,397 TONS ia She 10,240 TONS LEADERS AND DESTROYERS ——— | nei “27 SHIPS. 10645 TONS “| sEcons't NE SHIPS [ . YOR ESM TI, > rn BL a

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SCIENTIFIC AMERICAN Insular Irrigation May, 1924 Hawaii Finds It Necessary to Control Her Water Supply By Arthur L. Dahl ¥ wet area a constant supply of water is ob- tained and carried to the drier region be- low. Practically all of the ditch line is made up of tunnels, which are cement lined, and cost over half a million dollars to construct. To supplement the water supply during the periods when the rains fail, the company has developed a system of pumping plants to take water from the many subterranean reservoirs which lie under the fields. In the process of bringing irrigation waters to the low lands, some of the com- panies have found it necessary to con- struct long trestles to support the flumes across canyons or low depressions, and throughout the islands visitors can see \—emmees |ELISN we think of Hawaii we iD a) | are apt te msider it the + A () | garden spot of the world, a A here Nature has arranged L eA | erything to roduce the —— most luxuriant growth with the slightest effort of man This is true to a limited extent, for imatic conditions it deal for most tropi rop but the ingenuity of man has been called into pla; Oo insure in inv parts of the islands, the necessary irrigation waters for the fields of sugar cane, rice vr other native products, for while copious rains fall in the high mountains some of the iow lands do not get a ‘lent supply of water throughout the ¢ season to supply the ecroy with moisture There fore, the plantation engineers have gone into the recesses of the mountains and have built flumes and conduits to carry the surplus waters to where they will do the most good. Hawaii is a country of contrasts, for at many points towering mountains rise almost out of the sea, while at others the sandy shore rises slowly from the ocean level, and vast fields are available for growing crops, if a sustuined water supply is provided. A number of sugar companies on the island of Maui formed a cooperative company and at an The flume in one of the leading Hawaiian water developments difficulties had to be overcome, owing to the rugged and almost inaccessible character of the country. In build- ing this ditch it was also possible to generate electric current, for one of the ditches reached the plantation far above the area of cultivation, and a generating plant was installed to utilize the power drop without interfering with the use of the water for irrigation. The town of Lahaina is lighted from this hydroelectric these frameworks that support the life- giving waters that are brought from the rainsoaked slopes of the mountains to the dry areas below. One of them is illustrated. While natural reservoir sites are scarce, yet in some instances these have been found and have been devel- oped to regulate the flow of irrigation waters through- out the year. In one district the construction of a reservoir high in the mountains enabled a plantation to cultivate an additional area of cane land, and thus more than pay for the cost of the reservoir system. Nature, through her trade winds blow- expenditure of over a million dollars developed a water system for the sugar fields that brings the rains from the mountain slopes of East Maui through a system of canals ind tunnels over 40 miles long to irrigate the cane fields. The more available of these sources were tapped by the old Hamoakua ditch and by the Huiku ditch over twenty years age, but as the need fer more water increased, the ditch system penetrated many miles further into the mountains The latest Kauhikoa ditch consists aimost entirely of tunnels through the solid rock, for out of 23,500 feet of this new construction only 700 feet consists of open ditch, the remain- ing 22,800 feet being beneath the surface. The ditch°s are six feet wide and the tun- nels are seven feet high The water in the great Mal- iko guich through an inverted siphon this ditch is passed across pipe 22 inches in diameter and 85 feet in ing almost constantly against the high westward sides of the mountains, sup- plies an excessive rainfall to those re- gions, while on the low lands protected by the shoulder of those same mountains, the sun shines without interruption during the many months of the dry season. Man, by harnessing the rainsoaked slopes, and bringing into captivity the lifegiving waters, has made the low lands blossom with sugar cane and rice, and the other things which furnish food for people, and the work is still going on, so that event- ually every drop of water will be put to beneficent use. The Sense of Time N the Proceedings of the Society for Psychical Research (British) for July, Mr. S. E. Hooper has an article with the title “An Experimental Study of the Ap- preciation of Time by Somnambules.” It length. The longest tunnel on this ditch is over 3000 feet in length The mountain slopes of Hawaii are so precipitous that very little of storage facilities is afforded, and during the middle of the dry season it is often necessary for the sugar companies to supplement the water supply obtained from the mountains by pump- ing water frem wells sunk at various points throughout the fields. One plantation has installed pumping plants eapable of raising 30,000,000 gallons of water a day, and the same company installed a hydroelectric plant in connection with its mountain ditch sy# Irrigation ditch through a field of sugar cane power plant, and there is plenty of current to spare. The cane fields of the Hawaiian Commercial and Sugar Company, the largest sugar company in the islands, are watered principally by a great canal and ditch which brings water from the mountains of East Maul, a distance of over 50 miles. The upper reaches of these mountains are rain-seaked practically all the time, and by a system of four ditches heading into the is known that some hypnotic subjects dis- play what appears to be a supernormal power of appreciating the passage of time. If, for example, such a subject is told during hypnosis to perform some simple act at the end of 5000 minutes he will do so, at or about the correct time, although in the period intervening between the hypnosis and the ~ performance of the act he has had no conscious knowl- edge of the suggestion that has been given to him. Experiments demonstrating this peculiarity of the hyp- notic state have been recorded by Gurney, Delboeuf, srumwell, and Mitchell, and Mr, Hooper takes up the inquiry at the point at which tem capable of generating 875 horsepower, which power was used to operate pumps that elevated 6.500.000 gallons of water daily to a height of 574 feet, and then released to irrigate the cane fields. Another sugar company on the island of Maui has harnessed the waters from the mountains back of the ane fields, and in the process of bringing 5,000,000 galions of water each day to irrigate the s generated innd, sufficient electric powel by the falling waters to light all of the plantation buildings and supply power to pump 1,500,000 gallons of water from wells. The Honokahau ditch in West Maui supplies about 50,000,000 gallons of water daily, which is brought from the Honoka- hau Valiey, a distance of seme seven miles. The canal consists of 6% miles of tunnels, 400 feet of open ditch, and 1200 feet of 86 inch siphon pipe. The entire ditch and it was left by these observers. Two main problems are presented by the results of these experiments: (1) the subliminal ealculation by which the subject comes to know the time at which the suggested act is to be performed; (2) “true time-appre- ciation,” by which the subject knows when the time so calculated arrives. When a long time-interval is given in minutes the subject usually calculates subliminally so as to find out when the suggested act falls due. Mr. Hooper’s experiments cor- roborate this; but one of his subjects maintained that as soon as the suggestion was given she began to count rhythmically and continued to do so until the suggested number of minutes had elapsed. It is to such a capacity for accurate counting of seconds by a subconsciousness on which the pendular rhythm of the clock has been faithfully inscribed that Mr. Hooper tunnels are concrete lined and in the con- struction of this system many engineering Sugar mills at Hakalau, deriving their cane from irrigated fields looks for an explanation of “true time appreciation.”

Page 23

May, 1924 SCIENTIFIC AMERICAN Three views of the celluloid model of the “Shenandoah,” used in the novel stress tests. Polarized light is passed through the various members while under stress, and the nature and magnitude of the pull or push which they must withstand is shown by the rainbow colers of the resulting image Translating Stresses Into Color for Visual Observation HE Bureau of Aeronautics of the Navy Department has made a study of a celluloid model of the air- ship “Shenandoah” by means of photoelastic meth- ods. The work was done in the laboratories of the Massachusetts Institute of Technology. No. definite statement of the results of the tests can be made but Navy Department officials have expressed themselves as well pleased with the data obtained. It is believed that these tests will be of “distinct value” and of material aid in the design of airships to prevent a repetition of the “ZR-2” and “Roma” disasters, The model consists of several thousand pieces of celluloid machined precisely to scale and fitted together in a miniature duplicate of the airship. The testing was performed in the photoelastic laboratory of the Depart- ment of Physics by Dr. Paul Heymans and T. H. Frost, of the Technology staff, under the gen- lation of the information obtained experimentally by vision, touch and movement. The acquisition of greater skill affected not merely the hands but also the cerebral mechanisms that regulate all movements; and one of the ways in which this was expressed was in the attain- ment of a wider range and an increased precision of the conjugate movements of the eyes, and especially of a more accurate control of convergence. This did not oecur, however, until the flattening of the face (reduc- tion of the snout) allowed the eyes to come to the front of the head and look forward so that the visual fields overlapped. Moreover, a very complicated mechanism had to be developed in the brain before these delicate associated movements of the eyes could be effected. The building-up of the instrument for regulating these eye-movements was the fundamental factor in the evo- lution of man’s ancestors, which opened the way for the wider vision and the power of looking forward that are so pre-eminently distinctive of the human intellect. Our common speech is permeated with the symbolism that proclaims the influence of vision in our intellectual life. The first stage in this process seems to have been the expansion of the prefrontal cortex and the acquisition of the power of voluntarily extending the range of con jugate movements of the eyes and focusing them upon any object. Then came the laborious process of build ing up in the mid-brain the instrument for effecting these complex adjustments automatically, so that the animal was then able to fix its gaze upen an object und to concentrate its attention upon the thing seen rather than upon the muscular act incidental to the proc- ess of seeing it. This represents the germ of attention and mental concentration in general. But the power of automatically moving the eyes with such accuracy that the images of an object upon the two retinm could be focused with precision upon exactly corresponding spots made possible the acquisition of stereoscopic vision, the ability to appreciate the form, size, solidity, and exact position in space of object eral supervision of Professor Charles L. Norton of the Department of Physics. The phenomena of photoelasticity have been known to science for some time, but have been employed only recently to settle troublesome problems of struc- tural design, many of which cannot be mathematically determined. By this method polarized light is passed through the celluloid of the model under differ- ent loading conditions, and the stresses appear in rainbow colors. Since cellu- loid acts structurally as do metals used in construction, it is possible by varying the loads on the laboratory model, to determine just how the airship itself will act under various conditions. As Prof. Heymans states: “By this photoelastic method we can look into the vast and intricate network of the dirigi- ble and see exactly what is going on when it is laboring. We can see how she is carrying and distributing the load. We have made an analysis of the ‘Shen- andoah,’ saying exactly how the stresses are taken up by the members of the frame and the wires. When we hear of new forces which the ship must meet in its ventures overhead we can try them out on the model here at Technology.” Vision and Man’s Mental Powers HE first step in the evolution of man’s mental powers was taken when, in a very primitive and unspecialized ar- boreal mammal, vision became the domi- nant sense, by which movements were guided and behavior was largely deter- mined. One of the immediate results of the enhancement of the importance of vision was to awaken the animal's curiosity concerning the things it saw around it. Hence it was prompted to handle them, and its hands were guided by visual control in doing so. This brought about not merely increased skill in movement, but also the cultivation of the tactile and kinesthetic senses, and Hence, at this time probably for the first time in the history of living crea- tures an animal acquired the power of “seeing” in the sense that we ussociate with that verb. The attainment of these new powers of exact vision fut ther stimulated the animal's curiosity to examine and handle the objects around it and provided a more efficient control of the hands, so that acts of in- creasing degrees of skill were learned und much more delicate powers of tac- tile discrimination were acquired. Out of these experiments also there emerged a fuller appreciation of the nature of the objects seen and handled and of the natural forces that influenced the course of events.—Abstracts from address by Professor G. Elliot Smith, Ff. R. 8., be- fore the British Association, September, 1923. Under-Water Photographs from the Air HE airplane has opened up new worlds. One of them is a subma- rine world. Aviators flying hundreds of feet above a body of water can see submerged objects far beneath the surface. That is why aircraft were the deadly enemies of submarines during the late war, and why airplanes are now used to locate shoals of fish. And the camera, when equipped with the right kind of plates and ray filters, can penetrate the water even more suc- cessfully than the human eye. Objects submerged more than fifty feet have been photographed from an airplane. Hence it is now possible to make a_ rapid photographic survey of shoal waterways. Rivers like the Mississippi, with ever shifting bars, will hereafter be made safe by monthly or weekly mapping from the air. In earthquake regions such as southern Italy and Japan, the changing coast line, shallows and har- bors can easily be photographed after the building up of an empirical knowl- edge of the world around it by a corre- Submarine photograph taken from high in the air each new quake, thus keeping naviga- tion open and conserving lives.

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324 SCIENTIFIC AMERICAN May, 1924 Making High-Tension Cables By Francis A. Westbrook, M.E.

-ECTRICAL strung on poles along city conductors

| streets are often the object of condemnation by shade tree commissions, improve- ment societies and others and that is about ali the thought that is

given to the subject of electrical trans mission and distribution by the general From Old Rope and Oil Waste to Leak-Proof Conductors of Current P PUP eS SS Ce a product of the refining of crude oil; but the degree of refinement and the method of refining employed are of great importance. Not only is the insulating quality of the compound itself affected thereby but also the amount of it which can be absorbed by the paper. Further more, certain kinds of paper and certain kinds of compound go best together and public, except when something goes wrong . ae ee the problem is to find the combination and the lights go out When once the ET L,I TS ee which will give the best results for any conductors are placed out of, sight be Left: The sector stranding machine, which coils the individual strands of wire into cable. specified set of operating conditions . : . 3 Right: Winding the paper insulation off its spools and on to the cable. Below: The impreg- -_ low the surface of the ground everybody) These petrolatum compounds, as well as 4 me ¢ nating tanks < heaves a sigh of relief and forgets about i ~~" ; the paper, vary a great deal from time thei except the engineers who have to Three stages in the manufacture of paper-wound, oil-impregnated, electric ¢¢ time even when there is no apparent transmit the power over them and the cable for underground transmission of current reason why there should be any difference. manufacturers who have to make them, The engineers worry because it is becoming more and more of a problem how to carry etticiently the immense blocks of power which must somehow be con- veyed from the generating stations to supply the con- tinually increasing demands of industrial and domestic consumers. When one of the very new modern gene- rating’ stations is put inte service, it is not so difficult to build a sieel tower transmission line on private right of way as far as the city limits, but from there on to necessity located in thickly populated areas, it is a very different matter. As no city will permit very high voitage overhead lines it is the various sub-stations, of The character of the paper used is the subject of much attention—it must be strong enough so that it will not tear when wrapped around the copper con- ductor with adequate tightness, or when the finished cable is bent as during the process of reeling or un- reeling, or’ when being pulled into underground con- duit. Furthermore, it must be capable of absorbing the proper amount of oil, or “compound,” as it is gen- erally spoken of, not only between the fibres of the paper but also within the fibres themselves. It must be free from injurious impurities, and have the nec- essary electrical characteristics such as low capacity, high dielectric strength, and low dielectric loss. Paper suitable for a certain voltage may not be suitable for

imperative to install the conductors underground, and this greatly complicates the problems of insulation. It is not yet possible to make insulated eables for very high voltages when com 8 pared to those used for open wire lines. On the other hand, the voltage'(must be kept up reasonably high because it is not nossilile to transmit electrical power eco i nomically at low voltage. Consequently the central station engineer are clamor 4 ing for higher and higher voltage cables Fi and the manufacturing engineers are wrestling with the problem of how to make then : The highest voltage underground cables n ommercial service are for 45.000, and r some at 66,000 will soon be in operation : hut even this is not very high when com z

ee ee rd ¥ w— Lead Sheath Belt /nsu/ation Filler

mared to the 220,000 volt aerial transmis

sion lines now giving satisf: results outer ones. in California. In contradisti to this the making of even 25,000 volt under ground cables requires the greatest care

md involves constant electrical and chemical research, not to mention the attention which must be given to the technique of actual manufacturing and testing be- fore shipment. urious fact that the insulation for these eables is made out of old ropes and refuse from oil refining. To be mote specific it is a rather heavy Manila rope paper wrapped tightly around the copper conduetor in strips or “tapes,” and saturated with heavy mineral oil that is worthless for ordinary uses. Te ‘ At iS a ELS PF MY a Ee FEE OT RLY Bre It will be seen that with this shape of stranded conductor, the inner wires are larger than the Usually the strands are crushed together more than here appears. paper or jute “‘fillers”’ Cross-section of sector cable a higher voltage. It must also be capable of with- standing a high degree of heat without charring or “carbonizing,” as the cables become hot when carrying a heavy load. All this must be determined before the paper is used for every roll received from the mills, because it seems to be very difficult to make it of uni- form quality and there are continual variations of one kind or another. It is the same story with the impregnating com- pound. The material used is principally petrolatum—

Note also the for taking up the space between the insulated conductors Consequently these variations also have to be carefully aseertained by continual laboratory tests. Five tests on the paper, four on the oil, and three on samples of impregnated paper, made unre- mittingly, are the least number which will suffice to ensure good quality. At least twice as many tests have to be made at less frequent intervals. The heating of cables while transmitting power has been mentioned. This is partly due to the number of amperes of current being carried and can be kept within reasonable limits by providing sufficiently large con- ductors. There is another cause of heating from the “dielectric loss’ which occurs in the insulation and depends on the voltage and the nature of the insulating material. It is due to the electrical stressing of the insulation and the absorption of a certain amount of power. The temperature at which a cable can be operated is limited by the amount of heat which the insulation can stand with- out charring. That is, no cable can be successfully operated continuously above a definite temperature. The heating caused by the current which is flowing is to be expected and is unavoidable, but that caused by the “dielectric loss” in the insulation, which has nothing to do with the current, but nevertheless reduces the number of amperes which can be earried, can be controlled to a consider- able extent. The “dielectric loss” depends on the electrical properties of the paper and impregnating compound and knowing these from laboratory tests, it is possible to predict its magnitude. The insulating strength cannot be predetermined so easily but it is not entirely unpredictable. As regards the highest permissible temperature, this is limited by the properties of the oil and the paper. Consequently in designing a cable it is necessary to see that all the desirable characteristics will be attained with the ut- most economy both from the standpoint of cost of raw materials and the facility with which they can be put through the manufacturing processes. Having these requirements in mind let us now see how the cables are actually made. In the first place EAL, +

Page 25

May, 1924 there are two kinds of high tension cables—single con- ductor and triple conductor. Commercial transmission circuits are almost universally three phase and require three conductors. The three conductors may be twisted together and be placed within a common lead sheath so as to take up only one duct in an underground con- duit line. This has very definite electrical advantages as the magnetic fields surrounding each current-carry- ing conductor are neutralized by their close proximity. But for very high voltages, say 45,000 between conduc- tors, the insulation has to be so thick that, even if the proper manufacturing machinery were available and if the cables would not be too stiff to handle, it would still be impossible to group the three conductors under one sheath because the diameter would be so large that there is no conduit line in existence with big enough ducts to receive them. Consequently for volt- ages above 33,000, single-conductor cables are used. The conductors themselves are of stranded copper. In three-conductor cubles they are generally ‘ shaped,” as shown in the drawing; for it is possible to have a smaller diameter in this way. With single con- ductor cables the conductors are, naturally, round. The sizes of the conductor of course vary depending on the amount of current to be carried but 350,000 circular mils is used more frequently than any other for three conductor cables and it is about the largest size prac- ticable for very high voltages because, taken together with the thick insulation required, the final diameter will be the maximum which will go into existing duct lines. The stranding operation for round and sector con- ductors is carried out by different machines but they both follow the same principles. Take for instance a $50,000 circular mil round conductor... This is made up of thirty-seven No. 9 A. W. G. soft copper wires, that is, three layers wound in reverse directions around the center wire. The stranding machine is very long and consists of sections which revolve in opposite directions. The proper number of coils of wire for each layer is mounted in each respective section of this machine. There are six for the first layer, twelve for the second layer and eighteen for the third. The six wires or strands are twisted around the center strand, then the twelve wires over it in the opposite direction by the second section of the machine, and the third layer is formed by winding the eighteen strands over this with the direction of winding again reversed. This is known to the cable manufacturer as “concentric” stranding. The sector stranding ma- chine, shown on p. 324, also @ ‘sector consists of parts revolving in opposite directions and in which coils of wire are mounted but in this case the strands in different layers ure of different sizes, as the drawing indicates. This is simply because it is better for mechanical reasons to have the inner strands larger than the outer. That is, they shape up better and re- tain the sector form more securely than if they were all the same size. The application of the paper insulation is by means of a rather simple machine, which we show, but, as in almost any manufacturing operation, is accomplished with the help of a good deal of technique acquired through much practical ex- perience. As shown in the photo, the conductor passes through a long machine and as it does so the rolls of narrow paper tape revolve and wind the insulation " about it. of tapes are usually wound on in one direction and are then reversed. AS many as fifty layers can be applied at one passage through the ma- chine, sometimes more if the machine is very large, and if a greater thickness of insulation is required, it will have to go through again. As the paper generally used is five thousandths of an inch thick, one passage through the machine means one-quarter inch of insula- tion, which is enough for about 20,000 volts. For very high voltages it may be necessary to run through the machine three or four times. The technique comes in in winding on the paper with sufficient tension to ex- the machine. Above: SCIENTIFIC AMERICAN clude uir spaces between successive layers without tearing it. Another fine point is to have the spiral of “ach single tape with the specified uniform overlapping. After the copper conductors have been covered with the required thickness of paper they are taken to the “cabling machine,” if they are to be made into a three conductor cable. This is where they are twisted to- gether, as shown below. It works on the same prin- ciple as a simplified stranding machine where there ON te Pe LB la My o> The press through which the cable passes, after impregnation, to receive its coating of lead. Fed in at the back, it emerges at the front with the sheath- ing applied is only one layer. Three large reels of insulated con- ductors are mounted on the revolving part of the ma- chine together with spools of jute or paper strips, called “fillers.” which are fed into the spaces between the conductors as they pass through the die, thus giving a solid round cross-section to the assembled cable. The twisting of the conductors is accomplished by the turn- ing of the machine. Here again the question of tech- nique is encountered in the necessity of so operating the machine that the points of the sectors will actually A certain number Below: The reels, each carrying a single insulated conductor, and the spools of filler, in place on Cables and filler converging into the die at the extreme left, just beyond which the first layers of the “belt” are being applied The cabling machine, which twists the three conductors together, with the “fillers” for taking up the spaces between which would otherwise be void always point toward the center. After passing through the die at the end of the machine, and as a part of the same operation, the assembled conductors are given, just as on the insulating machine, one or two windings of paper tape to hold them in place. This is the be- ginning of the “belt,” or “jacket,” insulation which may be completed at this point but is sometimes finished on another machine just as already described for the in- dividual conductors, 325 The mention of the belt insulation brings up a sub ject which we have not yet considered. Each conductor has a certain thickness of paper around it so that the effective thickness between any two is twice that umount. This, of course, is designed to be adequate for the difference in voltage between conductors But the amount of insulation between a conductor and the lead sheath of the cable, or ground, is only that around the individual conductor and as the voltage to ground is more than half the voltage between conductors, it is nee essary to provide additional insulation. That is the fune tion of the belt, common to all of the conductors, Of course, an equivalent thick- ness of paper could he wrapped around each con- ductor but that weuld in- crease the diameter of the cable and use up much more paper and consequently more impregnating material—that is, the cable would cost more to make and would also re quire larger diameter, there- fore expensive, conduits. In fact, where cables are to be pulled into oid conduit lines this question of keeping down the diameter is vital. Of course with single con- ductor cables the “cabling” and “belt” operations are eliminated. The cable is now ready for the impregnating department but before actual impregna- tion is begun certain pre liminary steps are necessary. It must first be thor oughly dried. Even the driest appearing paper retains u surprising amount of moisture which if not removed very seriously diminishes its insulation strength. Dry looking paper contains, according to careful laboratory tests, about 4 to 5 per cent of moisture and ordinary paper as much as 7 or 8 per cent. Consequently the cable, on the reel as it comes from the insulating de- partment and weighing perhaps five tons, is placed in a hot air oven where it is left for several days. This long continued heating, called “preheating,” under con ditions where the air in the oven is kept dry, removes most of the moisture. The cable, still on its reel, is then moved into the impregnating tank, shown on p. 324, where the heating is continued for some time longer in vacuo. This re- moves whatever moisture remains along with the air from even the innermost strands of the conductors as well as from the tuberous fibers of the paper. The duration of preheating and heating in vacuo have been the subject of a great deal of experimentation, as a result of which sufficient data have been obtained to determine the proper periods for both treatments for the different kinds of paper, thickness of insulation, et« The impregnating compound is intrdduced into the tank while the cable is still hot and while ¢ is maintained. After giving the compound an oppor- tunity to soak into the insulation, a matter of from 12 to 30 hours, a high pressure is applied to drive it * " ? ne vacuum against capillary force into the channels of the paper fibers It seems almost incredible that the compound should penetrate through all the layers of paper and even in between the strands of the conductors but it is a fact that this does happen and it is very important that it sheuld do so. As already explained, air ionizes under the electrical stresses in high tension cables and causes deterioration of the insulation, so that it must be entirely removed and kept out. The only way to do this is to fill completely every pore and fiber of the paper, and every other bit of space between layers of paper and between copper strands, as well as all other unavoidable minute voids, with compound The application of the lead sheath is the last step in the manufacturing process. The cable is taken directly) from the impregnating tanks to the “lead press. It is important that the oil should not be allowed to drain out at this stage. The lead press, although a machine of great power operated by hydraulic pressure, is not at all compli eated. Pigs of lead are place in a tank to one side ef the press where they are melted but not heated more than enough to allow the lead to flow into a large eylinder where it cools down to a pl below the eyvlinder, as Shown above, is a sort of chamber into the back of which the cable enters through a closely fitting gland and out of which it emerges in (Continued on page 367) istic state. Just

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SCIENTIFIC AMERICAN For Faster Seeing May, 1924 Tests that Show How Better Lighting Makes Us See Faster as Well as Better By M. Luckiesh Director, Nela Park Laboratory of Applied Science 326 r wee | LEING an ol é ject involves time, inten sity of light character of lighting and many other factors. There- fore, in our industrious lives where seeing is linked with doing the question of light is very important. It was long ago recognized that improper lighting low- ered production, increased spoilage, and decreased safety but not much consid- eration has been given to the infinence of intensity ing black print on gray paper. Here the increase is very marked. Dr. P. W. Cobb is con- ducting investigations de- signed to be more analyti- cal. Up to the present time he has used parallel black and white lines as a test- object, as illustrated. In some of his experiments he has introduced confu- . sion patterns respectively before and after the pres- : entation of the test-object. ot pene arn ht bh | : / | These investigations are too | complicated for a detailed aceount here. Dr. Cobb found an increase in speed of light. That this is a fact but how much of a factor r the aperture FE, is a matter for careful and as desired. The head rests at tedious research. Everyone has had the experience of reading when twilight was falling. A careful observer would have noted thai it became to the eves as the intensity of light necessary to hold the printed page closer t diminished and that the reading became slower and less certain But this condition obtains at very low inten sities Nevertheless other factors, such as the ever present time element in seeing, suggest the possibility that even at higher levels, intensity of illumination plays a part in any act depending upon vision. Further more, light is enlivening and perhaps we may react more quickly under higher intensities than under lower illuminations. In order to convince ourselves that intensity of illu mination plays a prominent part in what may be termed the speed of seeing it is only necessary to provide a test-object containing various sizes of type and of Uilumination. C. H. Stickney de moving change the intensity vised a striking experiment shown in the lower picture The drum, containing letters of various sizes, is placed on the turn-table of a modern phonograph When it is n see only the larger illuminated to a low intensity we « letters at a certain speed but on suddenly illuminating it to a much higher intensity the ease of recognizing the smaller letters and even the large ones is very apparent. This strikingly illustrates the influence of intensity of illumination on the speed of vision but gives little idea of the magnitude of the-effect In order to determine the magnitude a number of tions were begun in Nela Research Laborator- gues chose first the very investigat ies. The writer and his coilea common process of reading. fter considerable experi- mentation an Old English type was chosen as best suited for the purpose. Owing to its complicated letters if familiarity with such type, the reader and to a lack « must scan all words more carefully than in the case of type. This is a desirable feature. A belt of a carefully governed common this printed matter was driven by mechanism (upper photograph and drawing) having a direct-reading speedome The printed underneath a slit wide enough so that ; er attached. matter passed several lines were visible. The observer controlled the speed of the mechanism so that he could have the lines matter pass at the maximum speed for which he could read aloud accurately. The intensity of illumi of reading nation could be varied within wide limits f tests on many observers show conclu The result of sively that reading can be done faster and faster as the intensity of illumination is inereased. There is evi dence that the speed of reading continues to increase as the intensity of illumination is increased far be rtificial light now in use. The yond iny intensities of bene print on both white paper results for reading b (reflection factor 80 per egnt) and gray paper (reflec- tion-facts per cent) are as follow: Tiiumination in foot-candies 2 4 8 16 24 Relative speed of reading; black print on 17m) 111° «121 23 18 100 125 160 188 204 white paper gray paper The black print on white paper represents usual read ing matter: however, much of our seeing is a matter of distinguishing lesser contrasts, hence the test involv- K matter The apparatus for the speed-of-reading test, shown diagrammatically and in use is easily determined C is a drum containing the printed matter, which passes under of recognition as the in- D is a white or gray screen; G an opal glass cylinder containing a lamp; F a screen. The light can be varied tensity of illumination was increase rr » 00 and the eyes see the printed increased from one to 1 at H foot-candles with no indi- eation that the increase would not continue for even higher levels of illu- mination When the illumination intensity was in- creased from 5 to 20 foot-candles, for example, the speed of recognition of the test-object appearing out of a clear field increased over 100 per cent. Over the same range the speed was increased about 75 per cent when the test-object was preceded and followed by Y These three patterns were presented in the order indicated, the first one remaining on the screen three times as long as the second, while the third was left on at the end of the test. The purpose is to measure the interval necessary for recognition of the presence of the intermediate object. It is found that this interval is longer when the “confusion pre-exposure and post- exposure” objects are used with it, than when it is used alone Another test for quickness of seeing confusion patterns. The latter case approximates the condition of a continuous visual process such as read- ing. Such work as Dr. Cobb is doing may eventually make it possible to appraise the increase in production likely to result from a proposed lighting installation. Now let us consider tests in factories. D. P. Hess and Ward Harrison have just reported an investigation in the inspection depart- nature of the work and the change in character and intensity of illumination. Recently a large factory re- ported an increase of 10 per cent in production in the daytime resulting from cleaning the windows. In all cases the cost of better lighting is such a small part of the value of the increased production that the better lighting appears to be eminently worth while economically. Iurthermore, these higher intensities and better light- ing make work-places safer and more cheerful. Much work remains to be done in order to establish accurate figures of the economics of better lighting in various activities but the data already available indicate that the entire lighting bill of this country would be more than paid for by the increase in production in the in- dustries. In other words, if factories were lighted to higher standards the entire lighting of this country could be accomplished at a net cost of less than nothing. Ammonia from the Air N 1899 Sir William Crookes pointed out that the world’s food supplies are dependent upon a supply of nitrogenous fertilizers to the soil. Each crop takes so much out of the soil that unless this essential ma- terial is replaced the yield per acre steadily drops. There is an inexhaustible store of nitrogen in the air, but nitrogen as such is one of the most inert of mate rials. It is only when it has been made to combine with other elements, such, for example, as hydrogen, that it becomes available as plant food. The problem in this case consists in taking from the two abundant sources, uir and water, the constituent nitrogen and hydrogen and combining them in the form of a new substance, ammonia, At the beginning of the present century there was no known method for any such fixation of nitrogen, but as the result of applying pure research there are already many industrial methods of fixing nitrogen in actual operation on a very large scale. This great result has been achieved in the important instance of the synthesis of ammonia. Thermodynamics supplies two of the most funda- mental laws of science. The first law is that we can not get perpetual motion, we can not get work for nothing. The second law is that all spontaneous pro- ceeds (and these only) may be utilized to give work. On applying these laws to chemical reactions Willard Gibbs, followed by van’t Hoff and others, obtained a mathematical relationship called the Mass Law. This law revealed the fact that it was within the power of the chemist to make the reaction 3H, plus N,—2NH, go in whichever direction desired, since the effects of changes in such factors as pressure and temperature could be predicted. The first problem was to find the most suitable equilibrium. This was done when it was found that the production of ammonia is increased by the application of 200 or even 1000 atmospheres’ pres- sure. The next problem to ment of a well-known fac- tory. They found an in- crease of 12 per cent in the production (number of pieces inspected of 44 work- ers) as the illumination intensity was increased from 5 to 20 foot-candles, The increased cost of light- ing was equivalent to only 2.5 per cent of the payroll of the workers involved so that there was a gain in production of approxi mately 10 per cent with- out additional cost. W. A. Durgin a few vears ago re- ported various increases in different departments of a number of factories. In his eases usually the system of lighting was greatly im- proved at the same time that the intensity of illu- mination was increased, be solved was the regula- tion of the temperature to give the most satisfactory yield. The ammonia must be produced at a practical rate and to bring this about substances termed “cata- lyzers” are employed to hasten the reaction and in addition materials called “promoters” have been dis- covered which increase the catalytic efficiency. By applying all these principles the Germans have already succeeded in producing ammonia at the rate of over 1000 tons a day. Thus, from the knowl- edge obtained by pure theo- retical and laboratory re- search, there has _ been achieved a result which is vital to the existence of the white population of the His increases in production varied from 8 to 100 per cent depending upon the speed of vision Apparatus, and manner of use, in a simple test for showing the influence of light intensity upon the dress by Professor J. W. world.—Abstract from ad- UcBain. ti si dy ro de in, po eV th eff po thi to by dr the ho wi Ka ani dy) wil an ste stu use

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May, 1924 SCIENTIFIC AMERICAN

The casing of a Kaplan turbine, showing the extreme sim- plicity of the guide vanes The rotor of a Kaplan machine of 1000 horsepower, and the tiny experimental model (below) A modern Francis turbine, showing the extreme weight of this part of the machine New water turbine designed by Prof. Kaplan of Czecho-Slovakia, showing how it contrasts in fundamental structure with the existing standards Speeding Up the Water Turbine By C. A. Oldroyd ORE power—more speed—at less cost: along these lines in one way or another, all modern power generators have been developed. Miles Standish.” This vessel is as nearly an exact copy of the original as the builders could make it, ex- cept in one important respect. The hull was entirely of steel. Her length was 102 feet, her ample beam was 24 feet, and her molded depth was 14 feet. The copied hull was mounted .by means of a

The slow steam engine gave way to the high-speed steam turbine of SHAFT. immense power; the huge water-

& wheel was superseded by the Fran- cis turbine, and here development nee ae seemed to stop. With the steam ot turbine the high-speed dynamo was /

introduced; and engineers longed y/ ay for a water turbine of correspond- GuiDE VANES. 4 ing speed

ball-and-socket joint on the top of a heavy concrete column, in such a manner that the director of the film could have it rolled in any way he desired. This work was performed by steam generated by two 25-horse- power boilers, and whether it was necessary to produce a gentle ground

/ oTop_ VANES. swell, a heavy beating-to-windward LROTOR_ Ae pitch, or a hurricane, or even to

After lengthy research, Prof. Kap- lan, of Brunn University, Czecho- Slovakia, hus now succeeded in designing a high-speed water turbine, a machine of extreme simplicity. In the Francis turbine, the water enters the rotor through a set of guide vanes surrounding the rotor; in passing through the latter, the water transmits its energy to the rotor. Such turbines have very large and correspondingly heavy moving parts; weighing many tons In the Kaplan turbine, the guide vanes lie at right angles to the rotor blades. The heavy rotor is here re- duced to a kind of ship’s propeller, having either two or four blades. Through such a turbine, the water can pass at very high speed, so that the diameter of the rotor can be reduced to one-half that of a similar Francis turbine. Chunks of ice, timber fragments, ete., which might wreck a Francis turbine, can easily pass through a Kaplan turbine. As a general rule, the Kaplan turbine rotates four times as fast as a Francis turbine under Section through a Francis turbine throw the “Mayflower” on her beam ends, the result was accomplished the instant the director megaphoned the signal. To carry the illusion further, a wall and bed of con- crete large enough to hold an acre of Sharpening a Thousand Chisels a Day By Francis A. Westbrook N those mills known as “granite cutting plants,” where blocks of granite are brought in from the quarries to be made suitable for building and monu mental purposes it is necessary to use a great many small cutting tools, which require frequent sharpening to insure a good quality of workmanship and efficient production. In a large cutting plant it is necessary to sharpen something like 1000 of these tools every day, so that unless proper means are employed to keep down the cost this might very easily be a serious item of over head expense. Very effective means have, been found in the adoption of the sharpening machine associated with the power hammer and carborundum wheel, as shown in the accompanying illustration. The arrangement is simply an adaptation of the moving platform idea with the other machines located with a view to maximum efficiency. however,

water was constructed. This minia- ture sea, when agitated, gave a very realistic representation of the At- lantic Ocean. The imitation was assisted by many sorts of ingenious water towers or “breakaways” by means of which hundreds of tons of water was hurled against the sides and over the decks of the little Pil- grim ship, quite after the fashion in which the ocean must have

The sharpening machine consists of an oil-burning furnace and two small moving platforms—one_ to carry the dull tools into the furnace and one to bring those which have been sharpened back again <FUioe Vanes Phe oil furnace, operated by compressed air under 95 pounds pressure, power hammer, and carborundum wheel are shown in the background of the picture. The left hand meving plat SROPELLET.

LAO.

handled her prototype in = 1620. If the shades of John Alden and Miles Standish were hovering about, we wonder what would have been their perplexed opin- ion of the performance! form, or chain, which is flat, carries Section through a Kaplan turbine’ the tools into the furnace where they are heated. A man sitting in’ front of the power hammer with his back toward the observer of the picture and with the carborundum wheel at his right hand, takes the tools

similar conditions, so that the high-speed dynamo can be directly coupled to the rotor, and belt and gear transmissions are done away with. From the photograph showing the cas- ing and guide vanes for a 1000-horse- power turbine, their extreme simplicity is evident. The Kaplan turbine has a fur- ther advantage, it shows no falling off in efficiency when running at less than full power. The rotor blades are adjustable, their inclination can be varied according to the load. The inclination is controlled by the large lever shown above the casing. The old “umbrella” type of dynamo driven by a Francis turbine impressed the laymen very much, but gave anxious hours to the station engineers. Now it will be superseded by fast turbines of the Kaplan type, with lightly loaded bearings and compact rotors. Standard high-speed dynamos, as used with steam turbines, will be employed, and in general appear- ance, such a plant will greatly resemble a steam turbine installation.

out of the furnace, hammers them into shape, grinds them while still hot, and then drops them back upon the right hand chain. This chain consists of a series of buck ets which are at first filled with brine to temper the chisels when they are dropped in hot. As the chain moves along and away from the operator the brine flows out and cool water flows in, so that by the time they have reached the end of the chain, in the foreground, they are cool. The chain then drops them into a recep tacle standing on the floor, which carries them back into service. Where Water Pumps Itself N Oregon mine, well up in the moun- tains, has taken advantage of its lo- cation to pump the water out of its gal leries, though its mean depth is about 600 feet, without any cost save that of in stallation. The water literally pumps it self. The secret lies in the fact that the mine location is such as to make possible the construction of a power flume, carry

A Movie “Mayflower” of Steel REPRODUCTION of the “Mayflower” re has been set up in Charles Ray studios in Hollywood, California, and was used in the filming of “The Courtship of The left-hand platform carries the dull tools into the furnace; the other, consisting of a series of small water-filled buckets, brings them back to the operator after a session with the hammer- ing and grinding machines in the right background The chisel-sharpening machine that keeps a big granite-cutting shop supplied with keen-edged tools ing the water off into one of the nearby valleys, and giving a 1500-foot head. Once the thing is started, it runs on indefinitely, the power from the flume being ample to run the mine pump.

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The boldest of all birds attacking a-red-shouldered buzzard, when the latter sought a roosting place uncomfortably close to the nest of the former The standing feud between the screech owl and the larger hawks peacasy | HE nature writers, some of them unfortu- | nutely fakers, have derived much sensation s from the imagined inclination of wild ani a | mals to engage in deadly struggles. Most ot readers enjey a fight, in the telling and especially so if the moral responsibility —_—_—— RY ae te ~ pte... for the lack of humanity happens to be wanting. *itched batties for the mere SCIENTIFIC AMERICAN May, 1924 Animal Animosities Fact and Fancy Regarding the “Deadly Hatreds” of. Wild Species By S. F. Aaron Drawings by canines. The deer and the hog have a similar but prob- ably a less purposeful enmity for all snakes. The well- known animosity of the kingbird toward nearly all birds which it must regard as potential egg stealers, the similar warfare declared by the purple martin against hawks and crows, the battles between robins and thieving grackles and the suspicions directed toward the jay by all small birds are merely develop- ments of self-preservation. The feud between the sparrow falcon and its much larger relatives the red-tailed and red-shouldered buz- zards is not so easily comprehended, for the big hawks cannot readily reach the young falcons in the narrow tree cavities and where the nest is always guarded; it may be mere suspicion and the knowledge on the little faleon’s part that the buzzards might enjoy fat voung falcon. The animosity shown is, nevertheless, out of proportion to its cause; the falcon, giving evi- dence of a wing power equal to that of any bird of its size, swoops from far above sake of fighting, or long con tinued contests for any causé ire rare, or may never occur \ among the highly organized ‘ creatures. Despite the contin tual struggle for existence be- tween those that prey or are preyed upon and the rivalries during the mating seasons the inhabitants of the wilds are generally prone to avoid hos- tilities that can gain them J nothing but wounds Most " ereatures fully comprehend their cwn powers and those of others capable of inflicting injury and they are unwilling to risk possible hurt or even engage in violent effort to little purpose. Thus the puma and the bears, though un- doubtedly possessing a hatred for each other due to their seeking similar came, hold a truce rarely if ever broken, the stories to the contrary be- ing pure invention. The bobeat ind the Canada lynx, in those regions where their habitats upon the back of its enemy, sometimes striking and tear- ing the feathers away, but rarely if ever disabling the larger bird so that its retreat is checked. Among the reptiles certain feuds exist that are more dif- ficult to explain; such is the king snake's desire to destroy all poisonous and some non venomous species larger and seemingly more powerful than itself. Nor is it understood why the rattlesnake shows a readiness to inflict its horri bly aggressive defense upon dogs, cats, larger birds and humans and regards with in- difference the nearness of horses and cattle, unless trod- den upon. Its enmity for the hog is natural enough. It may seem strange also, considering the small intelligence with which we credit reptiles in general, that the skunk and some snakes readily distin- guish herbivorous from carniv merge, fully respect each other, even when one is hun The flies generally begin these fights, vainly trying to pierce the beetle’s chitinous orous animals, fleeing from the latter and approaching coat of mail; then the PI gry and the other has made bestle seizes the marauder’s lee, and the latter usualls deer and cattle to feed upon a kill: and that these most escapes only by sacrificing that member the flies that they attract. grouchy carnivora, avoiding Robber fiy and tiger beetle It is among the insects and their own kind except during the breeding urge and at odds with all other creatures, keep from personal encounters is sufficient evidence of common inclination ‘The fighting of males over mistresses of a common choice is a usual thing among the mammals and birds, but these are individual affairs upon the spur of the moment and they rarely mean more than a brief scrap, y getting the worst of it, one contestant either quick! or the two backing off with mutual respect and each going its way. However powerful and possibly blood- thirsty the opponents, they are commonly too sensi tive to injury and pain to continue receiving it. This is also the ease among domestic animals, except when they have been especially bred to overcome fear and hurt, as the hbull-dog and the came-cock. With some species, as the flocking migratory birds, these rivalries are forgotten and the former scrappers mix amicably with each other Among the polyga- mous, continually breeding species of warm countries or that originated there, as the domestic fowl and the peacock, these rivalries continue end thus also with the herding mammats where the weaker males are per- petually driven off by those stronger. Feuds between different species, one or both of which threaten the safety of the other’s young, are not un common and this is the chief cause of such hatreds as exist between the wildeat and the wolf, the mink and the fox, the raccoon and the weasels. The enmity that the crow displays toward the hawks is an example and it is shown also by the suspicion with which all herbivora regard members of the larger felines and their allies that specifie ani- mosities are most bitterly expressed, though many of the more highly developed six-legged banditti know their peers and decline to mix with them in the strug- gle for existence. Others exceed the mammals in daring and pluck. The social hymenoptera with their stings as weapons for the defense of the colony habitations are examples of the highest development in the expres- sion of that which may be called nothing less than patriotism. The animosities these valiant little crea- tures show toward any enemy that may encroach upon the paper nest or the hive are endless. It may appear strange that the solitary bees and wasps do not show this same spirit generally in defense of their nests, but this is explained by the fact that the larger creatures give the diggers and mud daubers little concern and it may be assumed that the encroachment of moles or shrews or earth-boring beetles would be resented. A digger wasp that only preys upon spiders has been seen to attack and drive away a large grasshopper from the vicinity of the burrow. Whether fighting in defense of the nest or because of the desire for food the arthropods present the most daring and valiant warriors and the battles that re- sult are the most prolonged and vigorous. Often the size and prowess of the attacked cut no figure in the determination of the attackers. Thus the robber-flies, the assassin bugs, the tiger beetles and certain spiders eagerly seize upon creatures far larger and more powerful than themselves and those also capable of inflicting injury or death. The wheel-back bug, the cone-nose and the flat stink-bug, or any one of their the Author ussassinating relatives, commonly attack whatever may come within reach of their deliberate, but no less sure grasp and the puncturing power of their sword-like probosces. The intended victim may be endowed with sting or severing jaws, but the assassins do not hesti- tate and occasionally a yellow-jacket or a polistes wasp may be seen with its vitals pierced, effectively apply- ing its sting to the bug, one dying of enforced anaemia, the other of injected venom. Swifter of wing than most predacious hexapods, the robber-fly represents among insects the position of the hawk among birds; its attacks are often made in mid- air. It does not hesitate to pounce upon wasps or bees, generally seizing the victim from behind with its long, strong legs and in such a manner that it cannot be reached by the sting. Occasionally it risks too much, as when attacking the digger wasps; the extended and flexible abdominal petiole permits the sting to pierce the fly. The big, black robber-fly also sometimes clashes with the queen of hornets, the beautiful big sand-hill digger and there is either an instant separation of the contestants, om the robber drops lifeless to the ground before its stiletto-like proboscis can stab its opponent. In such cases, however, all the animosity is on the part of the robber-fiy. Tiger beetles also are willing fighters, often when they do not seem to gain food thereby, though this may result from error in picking the victim, which may make a victim of them. The Cicindela does not hesitate to come to grips with an assassin bug, the awful odor of the latter, which effectively warns away the verte- brate insectivora, having no terrors for the beetle. This is an affair that any lover of a good scrap will delight to witness: crushing jaws and a coat of mail against a piercing sword and if there is not too much differ ence in size and strength the more agile and better pro- tected beetle always wins by pinching off the probos cis, or the entire head of its adversary and then feed ing upon it. In like manner the tiger beetle’s armor serves a needed purpose when it attacks or is attacked by a robber-fly and this occurs not unfrequently. The beetle can seize only a leg of the fly and the robber cannot thrust its dagger into the beetle, but both are exceedingly persisent, rolling over and over in the effort to gain the fight, the robber’s wings keeping it gener- ally on top and eventually aiding it to get away, though often with the loss of a leg. A very certain animosity of long standing is evident by the contests between colonies of ants: notably the hig blacks and the equally large red and brown species, both common in our woodlands and fields. This is war with mob-like management, no drill nor general- ship exhibited, but none the less a combination of ac- tions and a determination that is worthy of patriotic emulation on the part of humans. For defeat only comes by total annihilation. Let the two colonies of these ancient feudists but chance to be established within ranging distance of each other and war is cer tain, one tribe as though at a signal making an on- slaught upon the other, perhaps coveting its stores of food, but it may he there exists an ancient hereditary enmity. The bug is the aggressor ; but occasionally it bites off more than it can chew. Against the wasp the assassin is very likely to perish by poison; though sometimes he is able to hang on and take out enough of the wasp’s internal organs to produce mutual death Assassin bug vs. mud-dauber wasp ~ nh ot . oe A Th an th ro mi sw th op The ha tre the int vel vel the the its the dui pre of is 1 thi to rea is cla

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May, 1924 Rotary Car-Dumping on a Giant Scale UMPING a fifty-ton car of coal in 1 minute 10 sec- onds, with only one man, unskilled, and a 35- horsepower motor—that is the feat being performed daily by a recent installation at St. Louis. With only the first unit of the Cahokia power plant completed at the present time the SCIENTIFIC AMERICAN turn movement by a limit switch and the rails are held in correct alinement by a solenoid brake. The outstanding feature of this car dumper is its fool-proof construction and its simplicity of operation. It is impossible for the operator to perform the cycle in any other than the correct way. 329 at the rate of twenty grams in twenty-four hours, the conditions for forest fires are approaching the danger line. This is a tentative standard, subject to correction as further data ure accumulated. Other conditions are taken account of in determining tire hazard such as the green or dry character of grass and weeds, the number of conifers in the for coal consumption aver- ages but eight cars a day. Under the burden of eight cars a day the continued operation of the dumper seldom ex- ceeds twenty minutes. The completion of addi- tional units will, of course, place a greater burden upon the dumper, but it is interesting to know that with this minimum load, the con- tractors feel the dumper pays for itself in time and labor saved. They contrast the rotary ests and se forth. In October the hazard is greater than in June with the same rate of evaporation. If some times happens that the evaporimeter absorbs a slight amount of mois- ture and actually be- comes heavier, At such a time there is no dan- ger of fire. The particular evap- orimeter in use at the Fremont Forest Experi ment Station is the standard with which others used elsewhere dump method with the bottom-dump method, which usually requires the labor of two men for thirty minutes to unload one complete car of coal. From the mechanical standpoint, the mechanism, as is the case with any rotary type of car dumper, has three distinct functions to perform, viz.: the rotation of the car through an angle which will permit the dis- charge of the material; support of the car on its tip- ping side; and the clamping of the car at Two views of the gigantic jaws of the rotary car-dump at Cahokia (St. Louis) power plant. Twenty minutes’ are compared. operation of the dump takes care of a day’s fuel—and in this brief interval the big machine more than pays for itself Determining the Fire Hazards in a Forest HE principle of the evaporimeter is applied in an interesting way in the inner-cell evaporimeter in- vented by Mr. C. G. Bates, Director of the Fremont Forest Experiment Station near Manitou, Colorado. In this special form of evaporimeter a round wick leads Others are made as nearly like this one as possible and calibrated. The cali- brating is done by placing the standard evaporimeter and those under test on a table which is exposed to the sunlight and rotated slowly and at a uniformi rate by a water motor, so that the conditions are exactly the same for all the instruments. Each evaporimeter is carefully weighed at the beginning and at the end of the test and the rate of evaporation com- the top. In spite of this multiple and seemingly complicated action, the oper- ator, in this case, has but one controller handle to operate. This controller is of the drum type, similar in design to a street-car controller. And while it pro- vides speed control its primary function is the starting of the rotating motor. All other operations are cared for automat- ically by limit switches. With the car in the normal position on the dumper the controller handle is in the neutral position. To begin the cycle of operations, the operator moves the con- troller handle into the extreme forward position. Rotation of dumper and move- ment of the transfer table start immedi- utely. Upon rotating ten degrees, a pro- pared. In making the comparison the ratio is carried to the third decimal place. Recovering the Weight from Burnt Fuel se maintain the equilibrium of an air ship inflated with either helium or hydrogen gas, it is necessary at times to “valve” or, in other words, permit some of the gas to escape in order to compen sate for the weight of fuel consumed by the engines, or to overcome the expansion of the gus caused by the heat of the sun’s rays. How to compensate for the weight of fuel lost and also to maintain the lifting fas aut an even temperature so as to con serve the costly helium, which in the fu jection (built on the side of one of the roller rings) operates a track limit switch, which in turn, starts the top-clamp motor, This motor pulls the four top-clamps downward simultaneously, until all four clamps have become firmly seated upon the top of the car and have exerted a predetermined pull on the operating cables. When this predetermined pull has been reached it dis- places an idler, operating a load switch, cutting off the motor and setting a high torque brake. With the car then firmly held to its dumping side and clamped at the top, Airship equipped with condenser for recovering water from the and thus compensating for the weight of the fuel burned up from a reservoir holding about a pint of water and connects with a flat wick spread over a disk about 44% inches in diameter. The flat wick represents the sur- face of a leaf. The disk on which the flat wick rests is perforated with a number of holes which may be con- sidered to represent the stomata of a leaf. Evapora- tion can, therefore, take place on the under side of the exhaust gases ture is destined to supplant the dangerous hydrogen gas in lighter-than-air craft, presented a difficult problem for Govern- ment engineers, Although the experiments were financed and sponsored by the Air Service, credit should be given to Bureau of Standard scientists for developing a really successful device. The condenser consists of a series of long slender pipes or tubes, .022 inches in wall thickness and one inch in diameter, comprising some 300 feet, through the inside of which gas is conducted on its Way from the exhaust manifelds the dumper continues to rotate until the rotating motor is automatically stopped by limit switches at the end of the rotating movement Up to this time all the opezator has done is to move his controller handle from the neutral to forward position. He now moves his con- troller handle through the neutral position and into the extreme re- verse position. This re- verses the direction of the rotating motor and the dumper returns to of the engine to the at- mosphere, The air, sweeping over the out- side of the pipes as the airship is in motion, cools the guses and the condensed water vapor is drawn off from a separator through ap propr iate! v located drains. The efliciency of the device is such as to produce enough water to weigh approximately the same as the fuel consumed, The apparatus, which of necessity had to be built as light as possible its normal position. On the return, when the dumper is within ap- proximately ten degrees of its initial position, the top-clamp motor limit-switch is tripped, which automatically reverses the direction of this motor; and counterweights raise the top clamps to their initial position. When the top clamps have reached their uppermost position the clamping motor is cut out by a limit switch operated by one of the clamps. The rotating motor is also stopped on its re- Assembled and disassembled views of the evaporimeter, and their susceptibility of the moment to fire wick. The metal cover above and in contact with the wick is blackened to absorb sunlight. The instrument is placed in an exposed position so that the wind can blow over it. The conditions of evaporation from vege- tation are, therefore, approached very closely. It has been determined that when water evaporates from the evaporimeter which we have just described which tells the moisture conditions of the forest trees in order to permit its use on airships, weighs only ebont 450 pounds, complete, is made of aluminum and aluminum alloys, and is ‘sufficient to take care of the exhaust from two 150-horsepower engines. The efficiency of the apparatus was evidenced by the recent successful trial flights of the Army Air- ship D-3 at Langley Field, Va., and the Aberdeen Prov- ing Grounds, Md., and it is quite likely that same will be installed eventually on all service airships

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adequate fruit because they are held back 330 (_o 1% progress of ideas depends | ef Al | much upon cross-fertiliza- ie | \ , | i tion Mans ideas never bear | | | —— j by present standards of scholarly presen- _ _——— tuti oe = on We need a more informal and unverified presentation of suggestive ideas, in order to speed up the fertilization process. ~“Some scientific jour- nals already approach the idea here suggested but do not, it is thought. official y recognize it. Among thinkers are those whose minds pursue a thought straight to its conclusion, with no difficulty in concentration, and perhaps with some difficulty in sup- plying illustrative and corroborative material. Opposed to these is the man whose mind strikes a subject like i dum-dum bullet \ im-dum spreads out at once, It tears a big hole, but it doesn’t get very far. The dum- dum mind finds difficulty in finishing what it starts, because the impact starts associations laterally in all directions instead of straight ahead. It is distracted by the push and pull from ail sides, and perhaps has an unconscious resistance against going ahead. Its results ire apt to be bulky but fragmentary, uncorrelated, not clean cut; in extreme cases, incoherent and ineffective, The dum-dum mind is less likely to produce com- pleted achievements of accepted merit. The “armor piercing” mind, however, would frequently fail to get its initial impetus and direction if it were not for some explosive, variant idea, originating in this or another mind. Very often such a stimulus comes from the combination of two widely different and previously separated elements. It is among such elements that the dum-dum mind is at home, If it be not fetching the metaphor too far, the dum-dum mind is then also like the explosive bullet or the secondary charge in the projectiles which reached Paris from the supergun; it sets in motion new forces, new lines of thought, by combining old elements To adopt a less crude metaphor: is it not true that | many minds secrete valuable ideas faster than they can a =sIEVERAL vears ago, AAS : experi in some ments conducted with high rotutional speeds, the attention of the Riverbank Laboratories of Geneva, [ll., was called to the relatively large amount of power required to maintain such speeds. As is well known, the head resistance of the air against 1 body moving through it is proportional to the square ol the speed with wl ich the body moves, and conse quently the power required is proportional to the cube of the speed. This means that doubling the speed of body quadruples the air resistance and calls The importance of this fact a moving for eight times the power, is well recognized in aeronautics. The fact that air- plane speeds have now been attained which are practi eally double the maximum attainable at the close of the war, and this with only a very slight increase of motive power, tells how successful aeronautic engineers have been in reducing the head resistance of aircraft. This naturally suggests the question of power losses due to air resistance in flywheels and line shaft pulleys. Of course, anybody who stops to think for a moment realizes that a certain amount of power is wasted in stirring up the air about the revolving spokes of a machine pulley While the conditions prevailing in the ease of a body moving through the air may not hold in the case of a revolving wheel, yet the facts cited above indicate that power losses, due to air resistance, yav be considerable ms The two practical questions that arise are. first, how much power is thus wasted, and second, how can this waste be prevented by means that will not cost more than the saving effected. The an- swer to these questions has been found by actual mea- surements only within the last year. One naturally thinks of trying the experiment of running pulley in the ir and in a vacuum and mea suring the power required in the two cases. Such a procedure is direct and scientific, but it is a fussy ex- neriment to perform, and offers no practicable means of eliminating the aste once its magnitude has been measured Stream-lining the spokes of pulleys is also a possibility, but it is an open question how effective such a method would be itn the actual case. The method finally ermploved will appear in the following description of the actual experiment performed at River- bank Laboratories. rhe power expended in producing a rotational mo- tion is given by the well-known formula §.OES32 H.P oe 6 M.. F SS000 in which Tis the torque on the driving shaft. The torque required to drive the pulley was measured by a SCIENTIFIC AMERICAN possibly be worked out in the form which standards of scholarship demand for reputation? Are not such ideas largely lost, like the spores of mushrooms or the myriad spermatozoa? The minds that give them birth are in many cases communicative but shy or isolated. Where they have been willing to give their .excursive specula- tions to the world they have been greatly appreciated even tho greatly criticized. Such, in widely differing Ways, were Nietzsche, Pascal, Amiel, Aurelius. Such a contribution, in a sense, is Jung’s “Psychology of the Unconscious.” Even where there is some interchange of ideas be- tween scientists of a given field, there is comparatively little cross-fertilization between academic departments. In lieu of compulsory continuation courses for all in- structors, or super-seminars, there should at least be informal interdepartmental discussion groups in every college faculty. May it not be possible to find some common channels through which valuable associations of ideas—flashes and glints which may or may not stand the assay of verification—may be put into currency and made per- manently available? This idea is itself an unverified inspiration, advanced for criticism, perhaps for experi- ment. It comes to us, in the first instance, from Prof. Thomas I), Eliot, of Northwestern University. It is proposed that the scientific quarterlies introduce an exchange and discussion department whose editor would seek for and select from the best commentary material secreted from time to time by readers and associative thinkers. Furthermore, reviews of other periodicals should in- clude occasional excursions into widely different fields, and might well be included in the same department from time to time. For such a department the name “Marginalia” is ten- tatively offered as suggesting the type of idea which simple, but very effective torque dynamometer, devised for the purpose. For the working out of the details of this instrument, credit is due Mr. B. E. Eisenhour of the Riverbank Laboratories. A standard % h.p. vari- uble-speed motor was nicely mounted on trunnions so as to be free to turn about the armature shaft. The test pulley was mounted on an extension of this shaft. The reaction of the load on the motor case tends to turn this. The force required to balance this reaction was measured upon a sensitive spring balance. The product of this force by the length of the lever arm on which it was applied gives the value of T in the equation for computing the horsepower. The speed was measured with a stop watch and a tachometer applied to the shaft. A wood pulley with a 6-inch face, 12 inches in diame- ter, with four flat spokes, each 414 by *%¢ inches, and a rim 7/16 inch thick, was mounted on the shaft. At a speed of 1840 r.p.m., the force on the balance at the end of a 2% inch lever arm was 3.375 pounds. The computed horsepower expended was .246, a very ap- preciable fraction of the load which such a pulley might be expected to carry. Two cardboard discs were then fitted to the two sides of the pulley thus enclosing the spokes. Under these conditions, the force was reduced to .25 pounds, at a speed of 1850 r.p.m., and the horsepower to .O18. The saving thus effected by the simple expedient of enclosing the revolving spokes was .228 horsepower. The process also materially increases the safety of such a pulley. In the following table, the results of a number of similar tests on pulleys of various types run at differ- ent speeds are given. These tests were made by Mr. J. J. Gibbens, Engineer for the Calumet and Hecla Mine. Type of Pulley Size R.P.M. Saving in H.P, with Discs, Steel, 6 arms........24" x 2” 550 -00375 et WOGG. .cccccceme S44” 1760 .029 Split Wood......... So” x 614” 300 0007 fh eee 12” x64” 100 00124 Split Wood soeeesde ae 500 .00149 Split Wood......... 12” x 64” 600 .00223 Se 8 ke 12” x64” 900 00536 Split Wood vscdaschee Or 1000 00756 Srey 12” x 3” 1000 .00372 It is to be noted that the power loss increases rapidly with both the speed and the size of the pulley. At first glance, these losses seem negligibly small. However, the operator who cares to apply these figures to his own power costs, taking into account the number of pulleys in an entire plant that are wasting that power throughout the year’s operations, will find that this May, 1924 A Scheme to Salvage Lost Ideas _ irsin"Cintatins might be mien in length to one paragraph; might be limited in each issue to one general field but the sub- jects announced some months in advance; might be made anonymously when desired, in order that no question of scholarship might inhibit the exchange of ideas, Tests of Natural and Culture Pearls A SIMPLE optical method of distinguishing the Japa- nese “culture” pearls from wholly natural pearls is described by Dr. FF. E. Wright in the Journal of the Washington Academy of Sciences, 1923, vol. 13, p. 282. In a bead of mother-of-pearl, such as is always used for the nucleus of the “culture” pearls, the nacreous layers are not concentric to the surface, but are approximately plane, being parallel to the surface of the shell from which the bead was cut. Now normal to this surface the reflecting power, and consequently also the opacity, is at a maximum); whilst at 90 degrees from this direc- tion (that is, looking along the lamin) there is a minimum of reflection and of opacity. A “culture” pearl when viewed in a strong reflected light (for exam- ple, with the observer’s back to the sun) shows at the opposite poles of one diameter a small bright spot due to the light reflected from the laminz of the enclosed bead of mother-of-pearl. In a strong beam of trans- mitted light (arranged in a closed box with lens and mirror, the pearl resting in a circular aperture) the “culture” pearl shows two positions of maximum opac- ity, whilst the natural pearl is the same in all positions. A third method, which is applicable also to “culture” pearls containing a real pearl as nucleus, is given by an examination of the walls of the hole drilled through the pearl. The pearl is illuminated by a strong side light and a minute bead melted on the end of a gold wire is inserted in the bore to act as a reflector, which is viewed under the microscope. The behavior is then substantially as in the other tests. wastage will represent the in vestment. Thus the total cost at eight cents per horsepower hour of the power loss in the 24 inch steel pulley given above will amount to about a dollar a year. The simple plan suggested of converting the wind-throwing pulley into a revolving eylinder will result in a saving of considerably more than it costs. The Use of Waste for Building Materials [* a lecture delivered before the Royal Academy of Arts, London, on Wednesday, November 21, Profes sor A. P. Laurie discussed the manufacture of build ing materials from such waste materials as blast fur nace slag, cinders, clinker, and, in the neighborhood of Edinburgh, burnt shale, the residue from the stills of the oil industry. There are three ways in which these materials can be utilized—for the production of bricks, for the production of cement, and as aggregate mixed with Portland cement or plaster of Paris. The general method adopted for the production of bricks is known us the sand lime process. Briefly, this proc ess consists of mixing the aggregate with a certain proportion of lime and water, squeezing it into a brick Saving Pulley-Power With Cardboard Discs siete intinsiderabie in under a pressure of some two hundred tons to the area of the brick and then steaming under high pressure or in open, steaming chambers. Bricks are now being manufactured by this process from sand, blast furnace slag, granulated by being run while hot into water, clinker, town refuse, slate dust, and burnt shale. Cement is being manufactured by two Scottish steel companies from blast furnace slag granulated, mixed with lime, and then raised to a high temperature so as to form a clinker in the same way as ordinary Port land cement was manufactured. This cement, known in Germany as iron cement, can be sold in this condition, or can be finally ground with a mixture of a certain proportion of raw blast furnace slag. The uses of these materials as an aggregate opens the question of how far it is possible to reduce the content of Portland cement, and at the same time, get sufficient strength for building purposes. The objec- tion to the usual building slab made of cement is that, in order to be able to remove it from the machine as soon as made, the content of water has to be kept low and, consequently, the crushing strength of the finished slab is also low. Two interesting methods of getting over this difficulty are the Crozite method, in which the cement bricks were sliced off from the bottom of a column of cement and aggregate, and the method in which a heavy compression is put upon the bottom and top of the slab at the moment of completion. The Crozite process is being carried on in America, = -_e-— Ne AE Ahem a re O* ery the The mar] by a and

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May, 1924 SCIENTIFIC AMERICAN outside the Tutankhamon by the Metropolian Museum of Art. View 2 is a small Gree} are mad of lightly fired soft pinkish els ptian discov- bronze horse which is given a place of high honor at the painted and pro ly date from the eightt 92 B. C. 3 head of the great staircase at the Metropolitan Museum of Christian era They may be egarded Art. It is only about 16 inches high, but appears almost of than pottery; there is so much expression heroic i i 25% pounds. It dates from about are relics of a time when the art of the We 480-460 ‘ It t Yr e seulpture. Views still, and they speak volumes of the i i of the East. All these figures are in the the ()NE of the most interesting finds Tomb, the most g jus and important ery is the tomb of King Seti I. (about 13 the XIX dynasty, in the famous Valley of the King’s To The ceiling in the sepulchral chamber is adorned with markable astronomical chart or list, which is now being studied by astron ers as well as arcl rists. View 1 is the hall 5 ¢ 5 Thi nat . ] i i anc Tr ians of Art, to which we are indebted for and views 3 and 4 show star li The tomb was excavated and the single B TO CHINESE STATUETTES ae

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SCIENTIFIC AMERICAN May, 1924 Terfezia leonis, one of the Terfa o highly The “Italian sometimes weighs twelve pounds usually projects out of the truffle,” Tuber magnatum, which The “white truffle,” Tuber album, which The “Perigord truffle’ or “French truffle,” ground Tuber melanosporum Four varieties of truffle, shown externally and in cross section; with, in three instances, a microscopic view of a single spore-sac with its contents Truffles and Truffle Hunters Some Details About One of Europe’s Lesser Known Crops and Its Harvesting By William Alphonso Murrill, Ph.D. New York Botanical Garden JEW native Americans know much about truffles because they hever saw any—except perhaps in siices on an oc- casional dish of meat served in a restaurant; but many of our foreign-born population know them intimately, because they are abundant in Italy and France and occur in smaller quantities in northern Eurepe and Eng- iand. The truffle gets its name from the Latin word Tuber and it oecurs singly or in smali clusters in the soil beneath cer- is rounded or irre gular, about the size of a walnut, tain kinds of trees. In shape, i devour them with the utmost enthusiasm. As the human nostril is not usually sensitive enough to detect this odor at a distance through several inches of earth, the prices of truffles would obviously be considerably higher were it not for the trained truffle-hunting pigs and dogs, which enter into the sport with great zest and are able to locate truffles under favor- able conditions forty or fifty yards away. The choice between pigs and dogs is one of economy, companionship, and the area to be covered. Dogs do not tire so quickly, but they are subject to more distractions. Water spaniels and pugs are frequently and varies in color and markings accord- covered with coarse warts. The color of Spore-sac and spores ing to the species, often being black and of Tuber known in Europe as used, being trained at an early age by hunting for food mixed with truffle peel- aestivum, : Q , 2 ings and buried in the ground. rhe the interior also varies, but it is always the “summer truffle” animal is never allowed to taste a truffle, solid like a potatoe and usually mottled or “English truffle.” any more than a setter or pointer is with white veins. Its most important It strongly resembles allowed to chase a rabbit. characteristic, by which it is detected and by reason of which it is valuable, is its decided aromatic odor This odor is sometimes offensive when mature, freshly gathered truffies are brought into a room in quantity; but in the young stages or when cooked it is always agree- ible, though sometimes rather weak When one hunts truffles in the woods in France or Italy, one goes first of all to the oak trees, the “Perigord -truffle” externally, but only so from four to eight large spores, which are beautifully and characteristically ornamented. The common hard-skinned puffball, which occurs so abundantly during summer and autumn on the top of the ground in thin woods, is not a trufie. There are other “false truffles,’ however, which are really good, such as the “red truffle’ of England, Welanogaster var- iegatus, which, although little larger than a marble, has a strong and agreeable odor and is *uten in the raw state with keen relish. Among the various species of truffles known to science, the following may be mentioned and_ briefly described : The Terfas, highly prized by the ancients, are well represented by Terfezia leonis, which is found in Italy and elsewhere in the Mediterranean region during the spring months and was reported from Louisiana in ISST as occurring plentifully in red sandy land near au river. It is smooth and pure-white when fresh, be- coming pale-reddish-brown on exposure to the air. The sacs contained eight spores, which were A well-trained truffle dog sells for from forty to” a hundred dollars. Truffles are also found accidentally when digging or ploughing; or a hunter of long experience may use his judgment and with some confidence dig in favorable bare spots under trees of the proper kind and age; or he may allow ) : 3 . conspicuously warted. This species resem- bles a potato externally and is eaten raw at times, being sliced and dipped in oil. thought it is without odor and its flavor is rather insipid. Several kinds of Terfas occur in Asiatic Turkey, Persia, the Lib- yan Desert, and Algeria, where they form an important part of the diet of the Arabs. They grow under species of Cistaceze in ind afterwards looks under beeches and hazel trees. They are alse to be found under chestnut, birch, willow, poplar, elm, ete., but not to the same extent. An old saving in France is, “if you want truffles, plant acorns:” and this has been done on a large scale in many of the truffle dis- tricts with great success where the drain- age is good and truffle-eating animals are excluded It would not be effective out- side of the truffle districts because there would be no spores or spawn present to himself to be guided by cer- tain small flies that appear In preparing freshly dug truffles for the market, the soil is first removed by the use of water and brushes made specially for the purpose and they are then graded by size and quality and preserved in cans, boxes, glass jars, ete. The best grades are peeled and the par ings sold separately at much lower prices. Truffles are used chiefly for dressing and start a crop, unless these were introduced in some form The time required to produce a crop of truffles after planting Oak trees varies with the sell and climate. Some truffles usually appear in five or six years, more in eight or ten, and a maximum harvest may be ex- vetween fifteen and thirty-five years. The soil should be light, well-drained, shaded, free from stones, jh ected and contain a certain percentage of both lime and clay. Warm weather and copious rains are essential, espe- cially in late summer. In dry seasons, truffles remain small and are liable to rot or be destroyed by insects. They are also ruined if the frost reaches them Most of the species are mature and ready for har- vesting in the autumn or at any time during the early part of the winter when the ground is not frozen, the full season extending frem August to March. They are found from a few inches to nearly a foot below the surface of the soil and are located by means of the strong aromatic odor which emanates from them. Squirrels, hogs, and other animals dig them up and Spore of Tuber canalic- ulatum, a new truffle recently found growing in Michigan As a food, truffles are wholesome and garnishing. As they do not keep well after being exposed to the air, it is wise to buy them in small containers and use them soon after opening. easily digested, while their aromatic qual ity undoubtedly promotes the digestion of foods with which they are served. The ancients dedicated the truffle to Venus as encouraging love, and in more mod ern times it was a current saying that “those who wish to lead virtuous lives should abstain from truffles.” Even in quite recent years, Elaphomyces variegatus, a fungus resembling a truffle in shape and habit, was commonly sold under the name of “Lycoperdon nut” for its supposed aphrodisiac qualities. False truffles may resemble the real ones externally and grow in similar places, but they can always be readily distinguished by their spores, which are borne free on the ends of minute threads instead of being enclosed in sacs. True truffles when examined micro- scopically are found to contain, imbedded in their flesh, numerous, minute, transparent sacs filled with Spore of Tuber unicolor, sandy soils containing lime, which are found near New York to frequent the truffle beds. City enriched by the overflow of streams after the heavy spring rains. As they develop very rapidly in favorable seasons, the soil above them becomes cracked or slightly raised, which betrays their presence to experienced eyes. Although classed with the edible truffles, they are so different (Continued on page 368) Spores and spore-sacs of Tuber Shearii, a new Ameri- can truffle from Maryland wa , a | in pk de t to

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May, 1924 SCIENTIFIC AMERICAN 333 Inventions New and Interesting A Department Devoted to Pioneer Work in the Various Arts and to Patent News The bumper that does not interfere with parking The Bumper that Is Never in the Way UMPERS are a very fine thing al- Ways, and a necessity sometimes; but every driver who carries them must have had occasion to curse the extra length which they add to the effective wheelbase, and the very lirge addition which they make to the difficulty of parking and unparking in crowded quar- ters. A “bumperette” of novel design is now offered, which protects the rear fenders and lamps satisfactorily, with- out making any material contribution to the difficulties of parking, and without interfering with free access to the spare tire, A Condenser for the Automobile | apm than a few automohilists have had the sad experience of discover- ing that the aleohol in their radiators has quietly stolen away on the wings of the wind, leaving their cooling system filled with a supposedly non-freezing mixture which is demonstrated, by the first real snappy night that ensues, to be aqua pura, pure and simple. The result in one instance that we know of was singularly fortunate—a weak cylinder- head gasket was the part that gave way before the push of the freezing fluid, insuring that no damage was done the casting itself; but everybody whose en- gine freezes up solid in this way is not so fortunate, We illustrate a little attachment that insures the permanency of the several parts of the cooling mixture. It is a con- denser, which in appearance and location is simply a radiator cap of rather large Radiator-cap that serves as condenser to prevent loss of fluid from the cool- ing system of the automobile size and unusual design. The saving of alcohol and the prevention of unexpected freezing are but two of its advantages. It prevents the evaporation of the water, even more effectually than of the alco- hol. This makes it possible to run in- definitely without the nuisance of re- filling; and it also makes practicable the use of soft or even distilled water in the radiator, thus eliminating the source of the major part of the dirt that clogs the average radiator so badly. Again, with the radiator always full, the solder is seldom or never exposed to the air, and hence its crystallization is prevented; and here is avoided the source of most of the spontaneous radiator leaks that are so annoying. Better Riveting Hammers OS features of the new riveting hammer illustfated here- with include bolted construction for holding the handle to the barrel; heavy- section valve with liberal bearing sur- faces; combination poppet- and piston- type throttle-valve; power in excess of all ordinary requirements; low air con- sumption; and exceptionally easy oper- ation. Three alloy-steel bolts of sub- stantial size, fitted with lock washers, hold the handle to the barrel, and enable the tool to be taken down for inspection or cleaning with the use merely of a a certain point, towards which a stand- ard car and the new all-weather cycle travelled. The distance at which the vehicle was first heard was carefully measured. The car became audible at a distance of 154 yards from the ob- servers: the motorcycle, which is fitted with a three-horsepower sleeve-valve en gine, was first heard when 70 yards away. The engine is completely enclosed, also the chain transmission. The frame is triangular and of a new design giving great strength and rigidity at low weight. The saddle is supported by a link and two long and powerful springs. Legshields .of ample size protect the rider in bad weather, while the engine and its working parts are quite as well protected as in a motorcar. Vaporized Metal [per yee statues, copper-cov- ered shingles, concrete piles or rail- road ties, are some of the possibilities ensuing from a process for spraying metals, which after years of study is approaching perfection at the U. S. Bu- reau of Standards. The essential of the process is that the metal is first vaporized by the use of electricity, and then sprayed on to the surface to be coated by means of a powerful blast which congeals it to the Newly designed riveting gun wrench—no vise, crowbar, or other tools being necessary. The throttle valve has the nicety of control of the piston valve, with the freedom from leakage of the poppet type. The throttle lever or trig- ger is made in one piece from special heat-treated spring steel, and has a long bearing in the handle which enables it to withstand a lot of abuse. The valve operates in a box of strong construction, located in the head of the barrel. It has a solid end, which makes it possible to take it apart without recourse to a serewdriver. This construction also per- mits a compression chamber in the valve box, which cushions the piston on the return stroke and prevents it from strik- ing the handle. The exhaust is through the side of the barrel near the handle, and can be steered in any direction by the operator. The All-Weather, Noiseless Motorcycle N three points the motorcar scores heavily over the motorcycle: in com- fort of travel, in protection from the weather, and in silence. But a new type of motorcycle recently brought out in England affords all the comfort and silence of a car; while also great strides have been made in protecting the rider from mud thrown up by the wheels. To test the silence of this new ma- chine, two observers were stationed at with outstanding advantages solid form as quickly as it strikes the surface. Applications of the method, which results in a firm coating of metal upon any surface to which it is applied, are many and varied. Stone, wood, metal and glass are all equally suitable basic surfaces. Pottery may be success- fully coated with metal, pointing to im- portant developments in ceramics. An important application is in the use of the metal coating in building con- struction. Shingles may be made fire resisting by coating them with copper, which weathers well and produces an artistic green color on the roof. Experi- ments are already being made along the lines of copper-coating other roofing ma- terial and stucco. Soldering of metal to glass, a difficult problem, has been easily accomplished by means of this method. first coated with a layer of copper and the metal connection is then soldered to the copper. Processes somewhat similar are used in the soldering of aluminum. On the decorative side the uses of the method are many. Statues or other sculptured designs may be hewn from soft and easily worked stone and then coated with bronze, giving the effect of a bronze statue and weathering equally well. Gold and silver plating or decora- tion may be applied in the same way to furniture or table ware.—Abstract from Science for November 9, 1923. The glass is British motorcycle that possesses several features heretofore obtain- able only in a regular automobile A Protecting Cover for Shallow- water Cables UBMARINE cables lying in the neigh- borhood of the coast must be pro tected in the water as well as on land against the chafing influence of the movements generated by the waves. Till now there has been used a flexible ar moring of thick steel wires, which pro- tected the inner parts of the cable very well. But this kind of armoring has the drawback that it cannot be made flexibie enough to follow the forms of the cliffs and stones on rocky coasts. Such a steel-armored cable, when lying on rocky shores, was partly on the ground, and partly hanging in the air. quently the stresses on the cable were far from uniform; one part was vio lently moved by the waves, the other one remained absolutely quiet To a new cable, laid recently on the Norwegian coast by the Siemens-Schuck ert Works, a new kind of protection was applied, which enables the cable to con form closely to all unevennesses of the ground, under water as well as on land This new armoring consists of link boxes of cast iron which overlap each other and are arranged in the manner of ball-and-socket joints. In consequence of their great flexibility these link boxes follow with the utmost accuracy the topographical formation of the sea ground as well as of rocky coasts. In order to avoid all movements, the cable armored in the manner just described is fixed on the rocks and on fitting parts of the coast with iron clamps The eable is arranged in the ship's hull with- Conse Not the latest sea-serpent——merely a scheme for protecting cables at and near their landing places

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Electric washer that clamps in place upon any tub out the link boxes and it is also laid out without them After the end of the ible is brought to lund these link boxes are installed Qn the dry rocks of the coast, this i shuple enough, In the not-too-deep parts of the sea the laborers tuke the cable after being laid out into af and install here he link boxes: installation of the clamps is made during ebb-tide. On the deeper parts this work The Hose-Holder for Fire- Fighters N° longer is it necessary for the fire- 4 fighters to struggle with a big hose, filled with an unruly snake of water that whips and struggles te get away from ther, and ills for the heaviest kind of handling in keeping it under control An Atiantic City inventor has put out a big. beavyv. nozzle-holder which holds the most powerful stream of water steady 1 rock. Not alone does if save the display of brute strength hich we are ecustomed to see at a fire it saves the services of three firemen to each nozzle mynd releases them for more active work, Also. it means that once set, the stream will be directed withont deviation or un- certainty upon the spot at which it is timed. The hose-hoelder comes in two models There is the type that clamps upon the side of the fire truck, as illus- trated: and there is a ground stand, for independen Use vithout inv further support At recent demonstration in Atlantie City twelve strenms ere shot fron : single ladder-trus without be ing touched by human hands after they h id once been set An Umbrella for the Spark Plug SHE little device illustrated, it is 1 claimed by its manufacturer, catches the flying oil and prevents it from foul ing the spark plug it attached by sliding it over the ground electrode, after closed hy bending the upwards over the electrodes. which the slot is shield Keeping the oi! and soot off the spark plug SCIENTIFIC An Electric Washer for Any Tub DECIDEDLY ingenious cylindrical LA electric washer that. clamps upon any tub or washboiler is different from others now on the market. Inside the eylinder is a little motor that water does not hurt. Neither does it drip oil. The motor runs a four-blade fan situated a few inches from the base of cylinder. This fan does the work by shooting out jets of water showing five pounds to the square inch by test. Water enters the cylinder through small holes surrounding the orifice of the jet When the water is thrown out it strikes along the sides of the tub, swirling the clothes with it in the process of cleansing. *aring the Phonograph Needle Without Removing It HERE is more than one good reason why a fiber needle should be used when records on phonographs are being played. There has, however, been the tiresome task of removing the needle from the tone arm in order to cut it off after once having been used on a record. A Chicago manufacturer has now per- fected a small metal cutting device that cuts the needle without removing it. It is run under the needle as shown in our illustration, and the lever pressed down by the first finger. This operates a cut- ting knife. Back of the cutting knife a small receptacle catches the discarded part of the needle. New But Simple Method for Changing Cast Iron Into Steel ‘7; of the most interesting develop ments in the realm of iron foundry practice which has been announced in several years, is the result of extensive experiment in research, largely during 1928. The findings are somewhat sensa- tional and revolutionary. A method has been discovered of heat-treating gray or white cast iron so as to render it much more easily machinable and at the same time to bestow upon it greater strength Rigid hose-stand for the fire brigade, which releases the firemen for better work than holding the hose than it has ever been possible to develop heretofore. Not only have the machin- ing qualities been greatly increased or benefited, but the strength and pliability of the iron has been strikingly aug mented. Tensile strengths as high as 98,000 pounds per square inch have been obtained together with a limited amount of pliability and also marked resistance to shock and fatigue stresses. The most interesting and notable fea- ture of this new process is the conver- sion of white iron into a product not only equal to but superior to malleable iron, in a period of time much shorter than that required in the regular malle- able process, The inventor of this process is Alex- ander K. Schaap of Brooklyn. The proc- ess, as thus far developed, is exceedingly simple and consists in heating cast iron AMERICAN to a temperature shortly above the tem- perature of 1600 degrees Fahrenheit, pro- tecting it in a muffle surrounded by a gas flame and opep at the top. In the eage of gray irof, as soon as it has reached the proper temperature, the muffle and its contents are removed from the furnace and allowed to cool in the open air, the casting being protected from drafts by placing a cover on the top of the muffle. The muffle itself is made of wrought iron and it has been found that this is the only material that can be used to obtain the results de- sired, muffles made of clay, graphite, steel and other metals being used with- out success. By this method it requéres only about fifteen minutes for the iron to cool to a black heat after which it is cooled in the air. The method as outlined above has been in continuous use for more than a year, chiefly for the purpose of softening gray iron for machining purposes and The fiber needle may now be used without the necessity of removing it from the machine to trim off the blunted end particularly for making automobile pis- ton rings. It may be stated according to the claims of developers that either gray or white cast iron is not only converted into a product similar to malleable iron but into one which has many of the properties of steel. If the results turn out to be as favorable as now appears probable, the process will mean the shortening of the time of converting white iron into malleable iron to less than an hour instead of 72 hours. The Magnetic Susceptibility of Gases HE method used in an interesting in vestigation by A. P. Wills and L. G. Hector was that of balancing the gus magnetically against an aqueous solution of nickel chloride. By varying the con- eentration of the solution it could be given a susceptibility approximately the same as that of the gas; then by varying the pressure of the gas or the tempera ture of the gas and soution, both could be given the same susceptibility. A man- ometric balance of great sensitivity enabled the observer to tell when the susceptibilities of the gas and the solu- tion were the same. For both paramag- netic and diamagnetic gases, formulas ure derived from which the susceptibility may be ecaleulated from pressure and temperature observations on the gas when it is magnetically neutral against the solution. The volume susceptibility under a pressure of the atmosphere at the temperature 20°C was found to be 10.1447 « 10-* for oxygen ;—1.64 « 10-” for hydrogen, and —0.81 x 10-" for hel- ium. The result found for helium is about 25 times less than Tiinzler’s value, but when substituted in the formula de- rived by W. Pauli, Jr., for the diamag- netic susceptibility of a monatomic gas, it yields a result bearing on the dimen- sions of the atom which is compatible with our knowledge from other sources. May, 1924 i ep — Ice saw that works directly off the motor Sawing Ice in a New Way YS away with the usual counter- shaft transmission of the conven- tional motorized ice-saw, the latest ma- chine of this description uses the small- cur engine, direct-connected to an _ in- serted-tooth buzz-saw. The resulting elimination of weight is a factor of im- portance, and in addition the cutting capacity, it is said, is increased. The frame of the apparatus practically sur- rounds the rapidly revolving saw, pro- tecting anybody who might come _ too close to it for comfort. It is entirely self-propelling on smooth ice, and has a cutting speed of three feet per second with a nine-inch cut. New Automatic Enlarger A PROPER darkroom is no longer re- quired for the use of the enlarger illustrated here; any room can be used after having been durkened. The special feature of this apparatus is a ruby lamp mounted to the foot of the second col- umn; this lamp is controlled by a double switch, which also controls the main enlarging lamp. A first pressure on the switch lights the ruby lamp, so that the sensitive paper can be placed in position, when the switch is pressed once more, the ruby lamp is cut off and the main en larging lamp thrown into the circuit. A few seconds suftite for the exposure, if fast bromide paper is used then the ruby lamp is switched on again, and by its light the enlargement is developed. The vertical column of the apparatus earries scales which indicate tie neces sary extension for the camera and its distance from the base plate. Once the scales have been properly adjusted, no further adjustment is required. Enlarging without a special darkroom > Wage > ae

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May, 1924 This vacuum-held rubber hook will support a twenty-pound overcoat The Vacuum Hook REAT holding power is claimed for this rubber vacuum-cup with flexi- ble rubber shank. Up to weights of twenty pounds it will firmly support whatever muy be hung on it—it is even used as an overcoat hanger. In window- dressing displays it should be found of great utility. It is claimed to provide a perfect adhesion to glass, marble, en- aumel, metal, polished wood, or in fact uny non-porous surface, without the use of glue, paste, stickers, or any adhesive substance. The Self-Sharpening Lawnmower \ HEN a lawnmower is sharpened in this device it is necessary to re- nothing but one wheel. In the place of this wheel a clutch pulley is fitted and this serves to turn the blades of the mower while they are being sharp- ened. Powdered emery dust or carbor- undum is placed on a piece of thin card- board and a thin paste is formed.by the use of a little machine oil and the reel draws in the compound as the mower is in motion. This compound on the cutter blades of the reel serves to sharpen the blades and the cutter bar at the same time. The motive power for running the device is furnished by a one-quarter horsepower electric motor. move A Bigger, Better Bath-Spray N this bath spray through holes in the metal container, back of the applicator portion, instead of from rubber prongs as in so many sprays. Six rubber prongs are arranged in a circle around the out- side of the container while in the center a round piece of sponge rubber is placed for use as a sponge. A sanitary feature of this spray is that the applicators may he removed for cleaning behind them. the water sprays groups of af Bath spray that gives a more effec- tive shower of water SCIENTIFIC AMERICAN New Wood-Drying Process by Ozone HERE are actually two principal methods for dryiag wood; open air and steam kilns. The open air requires from four to ten years, while modern industry requires a prompt supply of material. Moreover it entails the constitution of an enormous stock and the tying up of large capital. The steam kilns produce a dried wood but the amylaceous and the resinifiable substances undergo slow oxidation which is accompanied by contraction in the contents of the cells; as a result the wood gradually shrinks, the starch which still remains unaltered in the cells attracts parasites and gives rise to the formation of mold. Moreover, these unchanged components of the cell-sap are distinctly hygroscopic, consequently the wood absorbs moisture again from the air. The general effect is to leave the cells empty, thus rendering the wood brittle and lifeless. The process process of seasoning wood by Sharpening the lawnmower without taking it apart ozone produces a material well dried and seasoned. As a matter of fact, no process is capable of producing the same results as natural seasoning unless it provides fer the oxidation, without elimi- nation, of the organic components of the If an artificial oxidizing agent is employed for this purpose, it must act rapidly ; it must penetrate to the inner- most portions of the wood without affect- ing the ligneous tissue, diluting the sap, or discoloring the wood, and it must leave no residue. The oxidizing agents employed in chemical industry cannot do that. Ozone, on the other hand, ful- fills all these conditions and is capable of reproducing exactly the phenomena of seasoning by exposure to air, but at a rate many hundred times more rapid. The ozone wood-drying process was invented by Mr. M. P. Otto, a French Civil Engineer, Doctor of Sciences, who has devoted his studies to ozone and its results in all kinds of spheres. After a long course of experimental work Mr. Otto has now established it industrially. There are now in Paris and near Paris two plants which dry wood for all kinds of industries, the demands of which are so extensive that those two plants can- not meet the requirements of the manu- facturers. Some more kilns are to be erected in the near future. In Italy, at Seregno near Milan, there is another plant, and England is about to adopt the process. In the ozone process the wood is sub- mitted successively to the action of hot air, or ozonized air and of a mixture of ozonized air and hot air. The duration of the treatment varies, according to the nature and the thickness of the wood, from four to twenty days. In that period green wood is converted into seasoned wood possessing all the characteristics of wood exposed to the action of air for ten years. There is no case hardening, checking or warping. It must be pointed out here that wood brought green to the kiln comes out ready for use; therefore it is not necessary to stock before or after the process. cell-sap. The manufacturers using the process in France are unanimous in declaring that, after being finished, all articles show a perfect polish .equal to ivory, which proves that the wood is a com- pact and unalterable body. The “Con- servatoire National des Arts et Métiers” has examined the process in its experi- mental laboratory and fully confirms the results claimed by the inventor. A Bulldog Splice for Wire Rope HERE are legions of splicers, but most of them are larger than the wire. It has remained for a Mansfield, Ohio, manufacturer to produce’ one which when applied is no larger than the wires spliced. This simple little ap- pliance is made of bronze and has a number of teeth on the inner surface, whose purpose is to grip the stranded conductor and hold on tightly. It is closed by means of a hammer, and no solder is needed. The finished splice is covered with tape. There has been a long-recognized need for just such a thing as this, where work must be done in a hurry, and with portable tools. Measuring Strains by Electricity HE measuring of the strains of bridges, skyscrapers, airships and structural material in general has been made possible by electricity through the use of a device recently perfected by the U. S. Bureau of Standards. The device has the great advantage that may be read or recorded anywhere, although the gage itself may be in a difficult and inaccessibie location. The principle employed by the inventors, Messrs. B. McCollum and O. 8. Peters, is that of the varying electrical resist- ance of many closely adjacent’thin car- bon plates when subjected to a compres- sion or pulling strain. Heretofore there had always been insuperable difficulties in the way of practical application of this principle. The gage is now in use results The machine that runs through the entire catalog of woodworking oper- ations in a series of tests of impact strains on highway bridges that are being made at the Iowa State Agricultural College. The gage has also been tested on rail- way bridges. The device is small in size, being about 10° inches than tive inches wide, and about an inch and a half thick. The reading apparatus is a specially constructed voltmeter. By connecting wires from the instrument to an oscillograph graphic records of stresses have been made. The invention is not only very sensitive but it recovers itself so quickly after the strain has passed that it may be used in the meas- urement of vibratory or transient strains with a duration no greater than one long, less thousandth of a second.—Abstract from Science for Oct. Tth, 1923. The Woodworker’s Jack-of-All- Machines W E illustrate a clever new wood- working machine-of-all-work, which will do cross-cutting, ripping, mitering, bevelling, matching, molding, irregular shaping, dadoing, routing, sanding, bor- ing, turning, fluting, tenoning, and panel A wire splice that is no larger than the wire yet holds like grim death raising—-on any rake or bevel. It sounds like a large order, but the machine looks capable of filling it. There is a base casting, ports a sliding vertical column, and lowered by with crank attached. Ons crank raises the column one-eighth inch. The column horizontal arm, machined on the inside to receive a slide-block which carries a which sup elevated screw and bevel gears turn of the rigid Supports a one-piece yoke-and-motor assembly. This horizon- tal arm is thirty inches long.and swings right or left in a complete cirele. Grad uations at its point of contact with the column enable the i ¢ operator to set it quickly to cut any angle. The yoke is suspended from the slide block by a square-head shaft which seats in a milled way in the top of the slide block, The motor may be turned to right or left and seated in any of four 90-degree positions. The motor is pivoted in the yoke, swinging from horizontal to ver- tical and being held in either, or «any intermediate, Clamp nut. Ready means is provided for quickly de- termining the horizontal, vertieal, and 45-degree positions. with any stock up to twe inches position Dy The machine works Fountain Pen for Public Places EN service for lave no pen of their own is furnished by this recently patented writing The illustration shows the pen removed for writing. After use, the chain to which the pen is attached is pulled taut and run back in the base. It can be locked in any position for convenient use. A pull of the chain to the side between the small pulleys catches the those whe device. Fountain-pen service for the public writing-station

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296 vo Vith this simple combination of am- meter and variable resistance, any desired rate of battery charging may be obtained chain and holds it till released, while Within the base is a weight which pulls the chain back into the base after the writer releases it from its position be- tween the rollers Its operation is much the same as that of a windlass, Hoisting by Air F7HMHE air-moter hoist illustrated on [ this page employs a balanced three- eviinder air-motor which operates in either direction and at any speed or SCIENTIFIC hoist at any speed. A safety stop lever prevents over-running the top or bottom of the travel of the hoist. The automatic brake holds the load at any point for any time, regardless of the air pressure. The new hoist is marketed in five sizes, from five hundred pounds up to five tons. Variable Charging with Minimum Fussing NY user of constant potential, with 4 the aid of the simple connector illustrated, may enjoy the use of modi fied constant potential without the bother of buying a lot of vuariable-resistance connectors. The appliance consists of a special clamp fastened to the bus bars, into which is built a special carbon-pile resistance, together with an accurate- reading ammeter showing just the rate of charge going into the battery. By turning the knob below the meter, prac- tically any desired rate of charge may be obtained The connector is marketed with eighteen inches of Ne. 4 rubber- covered cable, and special battery con- nection, A Novel Pump of Fine Perform- ance MONG the interesting experiments A which come to our attention, a high place goes to the novel pump assembly which is now being tested out in the laboratory of Detroit University by Charles W. Jackman The left-hand member of our series of five photographs shows the set-up which has been used in AMERICAN Centrifugal Extractor of Interest- ing Design N the electrically-driven centrifugal extractor shown herewith, all belts, countershafts, ete., are eliminated. The motor is mounted directly upon the spindle of the machine—a_ distinctly modern tendency in the effort to get away from driving complications, and one to be observed in a very wide variety of electrically driven apparatus. The machine may be brought up to speed under full load in ten seconds and stopped in twelve. By means of a novel compensating feature in the assembly of the motor with the chip-pan unit, all the vibration so common to this sort of machinery is transferred to the base, where it is easily controlled. The lower motor-bearing carries radial loads only; the upper bearing carries radial loads, as well as the thrust load of the pan assembly, spindle and chip load. The weight of the entire assembly is carried by a pivot bearing in the base of the machine. The machine is equipped with a safety cover which automatically locks the drum control whenever it is raised. Not only is safety obtained by thus preventing the operation of the machine except when the cover is closed, but splashing of oil is also prevented. The chip pen has a capacity of two bushels, in the size now being marketed; but the same application will be made to other sizes in due course. The machine has an obvious availability for a large range of extraction work. May, 1924 Electrically-driven centrifuge of un- usual simplicity in design and oper- ation characteristic of the plant in this con- nection is that, unlike many alge, it ean flourish in water in excess of ten feet deep. An Electric Hand-Shaper LLUSTRATED herewith is an_ elec- trically operated hand-shaper of inter- esting design, shown at work. A specially patented cooling device permits the entire The complete test installation (left) and load within the rated capacity of the machine. The manufacturer emphasizes that this is not a direct-acting hoist. consisting as the latter do, essentially of only a plunger and a case. It com- prises an air-motor, geared through a mechanical train toe a hoisting drum. Throttle graduation is very fine, insur- ing instant and complete control of the Hoist driven by air-motor in a novel and better way four views showing the these tests. A trunnion has been brazed to the gear cover and a ball bearing (not visible) fitted to it. A second ball bearing is fitted to the shaft of the pump, and the whole affair including the short pipe-connections pivots on these bearings. A large tank is placed below the pump and the inlet is through a short vertical pipe. The discharge is from the top through the venturi meter and throttling valve. The pump is on its side to accommodate the connections The motor power available is a horizon- tal steam-engine, much larger than nec- essary, but giving a steady though flexi- ble flow of power. As for the pump itself, the present model is fitted with balance pistons on the impeller to eliminate end-thrust. The large out-swept annular volume is dis- placed twice in each revolution, giving a big output for the size of the pump. The discharge is perfectly uniform and pulse- less. The pistons are in constant con- tact with the casing, making the leakage small. There is no contact between pis- tons and abutments; and that between impeller and abutments is a true rolling contact on circular surfaces. The gear timing may vary within wide limits. The rubber covering of the abutment segment (shown in the final view) elimi- nates leakage between the abutments and the impeller during the period of rolling contact, the rubber being then com- pressed slightly. As a result of this, the volumetric efficiency is something like 90 per cent. working parts of a pump which has run under test with New Discovery in Mosquito Sup- pression oper discovery that a certain kind of alga growing im still or stagnant water has an important use in partially limiting the growth of mosquito larvze in such waters, announced in 1919 by a Spanish professor, has been supple- mented by another Spanish scientist who has now found a new and more effect- ive species of water plant, identified as Chara Hispida, which keeps the water in which it grows completely free from these pests. This plant was found grow- ing in the swampy regions near Valen- cia; pools in which it occurred were found to be completely free from the larvie, while other pools from which Chara Hispida was absent were found to be well populated with the wigglers. These observations made in the swamps were later confirmed by small scale experiments, in the course of which the larve of Stegomyia were introduced into water in which the Chara plant was growing. They all died. Further obser- vations in the laboratory and in nature have confirmed the essential antagonism between Chara Hispida on the one hand and the different kinds of mosquitoes (Stegomyia, Culex, and Anopheles) on the other. The hemp retting ponds near Valencia were later found to contain a rich growth of Chara, and to be entirely free from mosquitoes. Further work is being done with the view of enlisting the aid of this plant in mosquito eradication. A valuable volumetric efficiency of ninety per cent ussembly, motor and all, to be thus held in the hand while developing a speed, under load, of 8500 revolutions per min- ute. Without the load the oneeighth- horsepower motor attains as high a speed as 18,000 revolutions. The tool is obviously an extremely convenient one for a wide variety of small shaping jobs. The motor develops 8500 revolutions under load, but can be held in the hand without discomfort al h: to th a | su T! su en ha irt tic th: pre wi of ica sit pla ple sho bot tior at nal may at

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May, 1924 SCIENTIFIC AMERICAN _or 33 a The Heavens in May, 1924 Some Details About the Transit of Mercury, Occurring this Month HE present month is noteworthy for an unusual phenomenon, visible throughout the United States—namely, a transit of Mercury across the sun’s disk, on May 7th. On this date the planet comes di- rectly between us and the sun, so that it is visible as a small black spot upon the solar disk— too small, however, to be seen with the unaided eye, us it is only twelve seconds of are in diameter. A good field glass, equipped with a suitable shade to diminish the sun’s glare, should show the planet—and this may be a good time to remind ourselves that an old, fogged photographic plate, developed until it is so black that the sun can just comfortably be seen through it, makes an excellent shade for this purpose. The smallest telescope should show the planet dis- tinectly. The shade-glass should in this case be placed between the eye-piece and the observer’s eye, as any home-made affair will inevitably be of such optical quality that, if placed in front of the objective of the telescope, it would spoil the image com- pletely. The planet, as seen from New York, begins to enter upon the sun’s edge at 2:42 P. M., Eastern Standard Time. For points on the Pacific Coast the moment of entry is not quite a minute later, by Greenwich time (though obviously three hours earlier by local time). For all American stations the point of first con- tact is very near the uppermost point of the sun’s edge, as it appears in the sky at the time. Three minutes later the whole disk of the planet will have entered upon the sun’s face; and from this time until sun- set it will be visible as a black spot mov- ing slowly downward and to the right. The planet’s track takes it almost cen- trally across the disk, and the full transit requires about eight hours; but long be- fore that time the sun will have set for the western world. The end of the tran- sit will be visible in Europe, just after sunrise on the 8th. With a field glass, little more than the existence of a tiny black spot can be de- tected, and it may be hard to distinguish it from a sunspot, if there happen to be many of the latter—which is unlikely, as we are near the time of minimum. By making a sketch of any that are visible before the planet enters upon the sun, identification of the invader can be made certain—as also by the planet’s mo- tion. The observer must remember, how- ever, that the sun appears to turn, rela- tive to the horizon, as the day advances; and that a which is on the right- hand edge of the sun at noon will seem to shift about 40° toward the bottom of the disk before sunset—and be on his guard against confusing this apparent motion of the sun and his spots with the real motion of the planet. The changes in the distance of the planet from the sun's edge, of course, afford a safe guide. With the telescope it can be seen, if the air is steady enough, that the planet is perfectly round, with a hard, sharp edge—unlike the sun’s spots, which are irregular, and show less contrast. Under good condi tions, too, one may note that the planet looks darker than the spots—black, while they are brownish—a proof that the spots are not perfectly dark, but shine with a light of their own, fainter than that of the rest of the sun. The most important observations, from the astronom- ical standpoint, which can be made during the tran- sit are determinations of the exact times when the planet first invades the sun’s limb and when it is com- pletely projected upon it—and perhaps also photographs showing the planet in front of the sun; the object of both sets of observations being to find the exact posi- tion of the planet in the sky, compared with the sun at a known instant. In these days of radio time sig- nals, good observations of the time of internal contact may be made by amateur observers (with telescopes of at least six inches aperture, and good seeing), pro- spots spot At 11 o'clock: May 7. At 10% o’clock: May 15. At 10 o’clock: May 22. The hours given are in Standard Time. Bv Professor Henry Norris Russell, Ph.D. vided they have reliable watches, and compare them with the radio signals both before and after the tran- sit, without attempting in any way to regulate them between times. The Schedule of the Transits Mercury goes around the sun four times every year, and catches up with the sun three times. Why then are these transits so rare? As everyone knows, the rea- son is that the plane of Mercury's orbit is inclined seven degrees to that of the earth’s, so that the planet usually passes far above or below the line joining us to the sun. Only when a conjunction occurs close to the intersection of the two orbit-planes (the line of nodes), can there be a transit. The earth reaches these points in its orbit upon May 5th and November 7th, and all transits must occur within a few days of the one date or the other. The law of their repetition has been worked out in In 46 years Mercury beautiful detail by Newcomb. At 914 o’clock: May 30 must be made one hour later: 12 o'clock on May 7, etc. NIGHT SKY: MAY AND JUNE goes around the sun very nearly 191 times, and there- fore catches up with the earth 145 times. At only six of these conjunctions is he within the limits just men- tioned, so that the average interval between transits is about eight The actual interval between suc- cessive transits may be either 314, 7, 914, or 13 years, according to circumstances; but it never exceeds the latter value. November transits are about twice as numerous as those in May; because in the former case Mercury is much nearer the sun and may then be a greater number of miles from the plane of the ecliptic without getting out of the line between us and the sun’s upper or lower edge. The 46-year interval is not quite exact, though series of May transits succeed one another at this interval for about 400 years, and of November transits for more than 800. A longer cycle, of 217 years, during which Mercury makes almost exactly 901 revolutions, is much more precise, and transits, under very similar circum- stances, succeed one another at this interval for thou- sands of years. The last transit of Mercury was on November 6th, 1914, and was visible in the United States, as were those of November 13th, 1907, and November 10th, 1894, in whole or in part; also that on May 9th, 1891—the years. At 9 o’clock: June 7. At 8% o'clock: At 8 o’clock: June 22. When local summer time is in effect, they last previous May transit. The next transit, on Novem- ber 9th, 1927, will be invisible in this country, the op posite side of the earth at this time facing the sun. The four following transits, on November lith, 1940; November 13th, 1953; May 5th, 1957; and November 7th, 1960, will be at least partially visible in this country. One further interest attaching to these transits may be mentioned. Since Mercury moves much faster near its perihelion than near its aphelion, the ‘times of the transits are altered when the perihelion and aphelion move, giving us one of our most accurate means of determining such motion. It was in this way that the peculiar motion of Mercury’s perihelion was first dis- covered—to be a puzzle to astronomers for a genera- tion, and to be at last accounted for by Einstein The Heavens The Milky Way sweeps far along the eastern horizon —too low to be conspicuous itself, but marked by many bright stars. Scorpio is in the southeast, not fully risen. To the left is now brightened by the presence of Jupi- ter. Then comes Aquila, and Cygnus, in the northeast, with Lyra above. Cepheus follows, and last Cassiopeia, low in the north. Ursa Minor and Draco swing high over the pole, and Ursa Major is far up in the northwest, extending al- Ophiuchus, due east, most to the zenith. Auriga and Gemini are setting, far below. Hydra stretches along the horizon from west to south, with Corvus and Crater just above and Leo and Virgo higher. overhead. Far below on the southern horizon is Centaurus. The brighest stars of the constellation, Alpha and Beta Cen tauri, are visible at this hour from south- ern Florida and the West Indies; and the Southern Cross, also low on the hori- zon, an hour or two earlier in the night todites is almost The Planets Mercury is an evening star before his transit, and a morning star afterwards; but he is visible only near the-end of the month, when he rises at 4:45 A. M. Venus is extremely conspicuous as an evening star, far north and very bright, remaining in sight until 10:10 P. M. on the 3ist. Mars is past quadrature, and steadily getting brighter and slowly eastward through Capricornus. By the 3lst he rises at midnight and nearly twice as bright as Arcturus. Jupiter is in Ophiuchus, approaching opposition, and rises at 9 P. M. in the middle of the month.. Saturn is in Virgo crossing the meridian at 10 P. M. on the same date, Uranus is in 2 A. M.; and Neptune is i shortly after midnight. The moon is new at 6 P. M. on the 3rd, in her first quarter at 9 P. M. on the 11th, fuli at 5 P. M. on the 18th, and in her last quarter at 9 A. M. on the 25th She is nearest the earth on the 23rd, and farthest on the 5th. As she makes her circuit of the sky, she passes by Mercury on the 4th, Venus on the 7th, Neptune on the 11th, Saturn on the 16th, Jupiter on the 19th, Mars on the 24th, Uranus on the 26th, and Mercury again on the 3\st. nearer as he moves looks June 14. Pisces, rising Leo, setting awa\ Distribution of Brightness on the Sun’s Disk NCHWARZSCHILD and Defant’s ! Ss work, developing Schuster’s investigation of the decrease in | right ness from the sun’s center to limb, seemed consistent with the supposition that the sun consists of which radiates like a black body, cooler gaseous atmosphere which scatters this radiation But St. John’s work, developing Evershed’s discovery o radial motion in sunspots, assumes that the sun is gaseous throughout, the Fraunhofer lines ) duced by absorption at different levels. A paper by R. Dietzius (Akad, Wiss., 131, 2a, 1) is now o show that Schuster’s law of decreasing brightness can be explained quite as well, or even better, on this theory of a completely gaseous sun. 1 HUucieus surrounded by e being pr offered to

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290 vv

In the Dead of Night In the dead of night a fire breaks out—the alarm must be given. A child is taken sick—the doctor must be called. A thief enters the home—the police must be located. In the dead of night the American turns to his tele- phone, confident he will find it ready for the emergency. He knows that telephone exchanges are open always, the operators at their switchboards, the wires ready to vibrate with his words. He has only to lift the receiver from its hook to hear that calm, prompt “Number, please.” The constant availability of his telephone gives him security, and makes his life more effective in wider horizons. Twenty-four-hour service, which is the standard set by the Bell System, is the exception in the service of Continental Europe. An emergency may occur at any time. Continuous and reliable service has become a part of the social and economic fibre of American life. AND ASSOCIATED COMPANIES ae >) AME (a) BELL SYSTEM rae, Qe LO” One Policy, One System, Universal Service Send ~ FREE BOOR , " NG- WHAT BAITS WHEN * RICAN TELEPHONE AND TELEGRAPH COMPANY

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Every fisherman should have it. Inter- esting angling hints. Tells what baits ’ Bach of these sure sag raising to use for every kind of tishing @ comple ruction ver lectricity Auto ~mobile Mac nine st op. Carpentry Postal gets it! neering, Railroading and twenty SOUTH BEND BAIT CO. cateiogue F ‘REE A postcard 1558 High st, other trades. "Pull b nes yours rahe « > , . 77 , > : « = ‘ ‘ wave lengths used by the British broad- | Plibrico is delivered only in steel con- casters. The Pittsburg concert, via London, | tainers of distinctive appearance as was picked up in Caleutta, India, and held shown below. Warehouse stocks in 70 cities—see ‘phone books. thirty-two minutes. This system short-wave transmission and repeating enabling the British audiences to listen to American radio programs, and even the| Freneh, Belgian, Dutch and German listen- ers-in may have an opportunity of listening to the fascinating strains of American jazz for of | is FURNACE LINING 4

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via the British repeating stations. Doing Away With the “Pick-Up” Wires The possibilities of short-wave transmis Get the sion penetrate even deeper than this — FREE book the future of radio broadcasting. Broad : wit end dee easters from time to time find it necessary trouble; no obliga- to transmit directly from some point out- tion. side the studio. It may be a banquet, a baseball or football game, the ringside, the theatre or opera, the convention hall; but whatever it is, the usual studio microphone

is replaced by a microphone in the field, so Jointless Fire Brick Co., 24 | to speak. The “pick-up” equipment, to use i 1159 Clay Street, Chicago, Ill. radio parlance, has heretofore been con | Please end us the free book. | nected with the broadeasting station by means of telephone or telegraph wires. Such Firm ad | means have been ample for the purpose, | although, truth to tell, there have been} Address soseenneeeetnnnnnnneenee many times when the broadeasters have 7 found it difficult and, sometimes, impossible to obtain the proper wire connections, with | ; | |the result that the radio audience have emenenans le ¢ | missed important events. And now we have ee ee ee ee ee ee ee oe a (Continued on page 354) ™

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May, 1924 SCIENTIFIC AMERICAN 339 C4) \ y, >) for a two tube EP as. : NEW two-tube RADIOLA— designed and built by world- You Can Add famed engineers in the great RCA laboratories—priced at At $35 Radiola III. Two Radio- a Radiola, less than you could build it for at home! A real RADIOLA— = speaker, $36.50 : ; trons WD-11. Head tele- . Pai weg a including the tubes and the headphones. A new model. Improved s. , a adi a mpli- a + . thing except the dry bat- fier push-pull) to get long in sensitivity and selectivity. Getting distance on the headphones, teries and the antenna. distances with a loud- " anges speaker. Including two and near stations on a loudspeaker. Receiving clearly—repro- ENS EPR E, S20 ducing truthfully. Its thirty-five dollar price means at last that Or Buy Complete every home everywhere can tune in on the fun with a small RADIOLA IILA, the amplifier combined with Radiola receiver built for big performance. Ill in one cabinet; with four Radiotrons WD-11, head telephones and Radiola Loudspeaker . . . . $100 Operates on Dry Batteries “There's a Radiola for every purse” Radio Corporation of America There are many Radiolas at many prices. Send Sales Offices: for the free booklet that describes them all ‘ ; 4 > bx “ 2 ne: , " 233 Broadway, New York 10 So. La Salle St., Chicago, IIL 433 California St., San Francisco, Cal. ee ee pennies ‘ be J & RADIO CORPORATION OF AMERICA | Dept. 125 (Address office nearest you. | Please send me your free Radio Booklet. ees © Name protection | : , {a Street Address ia! ie eee ce —_ : H | City R.F. D. ar) REG. U.S. PAT. OFF. i ae ee ey State | ADD :

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340 SCIENTIFIC AMERICAN May, 1924 Cut Plant Painting Costs These Three Essentials Save You on Plant Painting 30%, Vortex paints are full bodied oil paints of the highest qualicy for interior or exterior use. They are specially prepared for me- chanical application. Vortex Paint The Vortex Meth od is different. A good many Plants creased their Light and Production by this have in low cost sys- tem to 50% A handy man at your plant can easily operate the equipment and we will instruct him how to handle it properly. Paint, us and you will have incurred no expense. Write us now Our Demonstration Offer If you have painting to do we will send Vortex strator to your Plant to show you just what we have stration you may If you do not approve the demon- We loan you the Vortex Equipment. It operates on a different principle than ordinary spray painters— longer range, greater speed, and confined paint delivery make for better, cleaner and less costly results. Equipment and a Demon- send everything back to ” A_ 30° diameter Dings "High Intensity’’ Mag- netic Puliey removing tramp tron from 300tons of coal per hour at Colorado og and Iron Co., Pueblo, Colorade, Coal pane Ee machin- ery protected from breakage and iron that is worth money is re- claimed. See, Y Magnetic separation saves : ters in mines, mills and ame! ‘tterien Dy preventing pecks in china rwe w*plante and Dt iver | ized fuel plants by protect i ing crushing equipment in quarries by prote pc tit Lg | erushins equipment from | breakage in cotton seed mii jeby pre | linters anc hullers | cleming OY { chicory, crucible clay, vegetable Tramp iron like this —wrecks crushing and grinding equipment lowers quality of many manufactured products —causes fires and explosions in mills TRAY or “tramp” iron causes a lot of trouble. If it gets in crushers in mines, quarries or elsewhere it may wreck them, causing plant shutdown. In manufactured products — like ink, china, glass, foods, chemicals — it lowers quality. In grain elevators and mills a spark from iron in the crusher may cause a disastrous explo- sion. You can’t keep iron from en- tering raw materials — but Dings “High Intensity” Mag- netic Separators will remove it wherever its presence is dangerous to equipment, raises manufacturing costs, or is a menace to quality. The list opposite suggeststhe wide range. Write for bulle- tins for each industry to— Dings Magnetic Separator Co. 709 Smith Strect, Milwaukee Separate > phone book . for branches in bulletins New York, Den . yer, Richmond, describe it, Chicag h neh, Lois, “ae MAGNETI aaa Ask for Angeles = ae Sai your copies. ity. The Scientific American Digest A review of the technical and trade press, consisting of abstracts | from leading articles announcing the newest develop- ments in industry and engineering Exact references to the sources from which these abstracts and quotations are made follow each abstract, the numerals referring respectively to the volume, number, and pages occupied by the original article in order that those who wish for further data may refer to the originals. Other digests appear elsewhere in this issue Automotive much to the surprise of the committee as , ‘ . well as to leather men, it has developed that Changing to “Balloon” Tires.—Both I balloon and “balloon type” tires are straight side and no expense is connected with chang- ing from regular to “balloon type” tires on cars equipped with straight-side rims. In the ease of ears using clinchers, the cost of the changeover is only that ordinarily incurred lin changing from clincher to straight-side rims. On the other hand, in changing from regular cords to balloon tires on cars already in use, either new wheels or necessary, usually new wheels. and Lincoln ears the rims cannot be changed and new wheels are required. type” tires can be applied with no alterations whatever to cars having sufficient fender and body clearance. This clearance must be measured between the tread of the tire and the fender at the top, forward and rear ends of the latter, also between the side of the tire and the side of the body and between | the side of the tire and the outer edge of the fender. Some cars have more fender and body clearance than others, and for that reason single and double oversize “balloon | type” tires are made to fit the most com- monly used rims. The single oversize “bal- loon type” tire can be used in all cases, but when attempting to apply the double over- size, careful measurement of ail clearances is necessary, not forgetting the use of chains in winter and that heavy loading of the car may produce sufficient sag in the springs to cause the fenders to strike the tires in crossing obstacles. The effect of these larger tires on the gear ratio and effective power is also to be considered.—Ind. Rub. World 69 :6, 2 pp. What is a Balloon Tire? confusion already exists in the tire trade, and still more in the public mind, as to the proper answer to this question. The term has been commonly applied to a great many sizes ranging from the 29 by 4% and 30 | weight of the engine. | | should be | ©, | Lake | ards. by 5 six-ply so-called “taxicab” tires requir- ing an inflation pressure of about 40 pounds, to the 34 by 7 four-ply thin sidewall tire designed for inflation pressures as low as 18 | or 20 pounds. Leading tire manufacturers | have therefore become apprehensive lest the public, hearing of the successful use of bal- loon tires at inflation pressures as low as 18 pounds per square inch, will jump to the conclusion that all tires termed “balloons” ean be used at this low pressure, and that the results will be disastrous. To offset this tendency some are recommending, even for “true” balloon tires, a pressure of about 36} pounds, despite the fact that at this higher | pressure much of the cushioning value of the balloon tire is lost and punctures are said | to oceur oftener because of the higher unit pressure between tire and road. Mean- while it is well for everybody to note the marked distinction which exists be- | tween balloon tires and “balloon type” tires. As shown by the appended table of ap- proved tire sizes, balloon tires are manu- factured for wheels and rims of three new and special dimensions only, namely 20, 21} and 22-inch. “Balloon type” tires are pro duced to fit the wheels and rims now in common use. There are now 215 sizes on the approved list of the Rubber Ass’n of Am. Proper inflation pressure depends as always on the load, but contrary to the | former practice the front tires require about five tires rear the gage uniformly pressure than the empty, due to A low pressure the inflation pounds when more the car is used and maintained. four-passenger pounds front and | Mamta Rub. pheton, for example, 25 pounds rear is about World, 69:6, 2 pp. Startling Results from Leather Re- search were reached by a large number} **| of tests conducted by the Bureau of Stand- | These tests have sought to determine! the physical properties of leather, especially | of torque delivered to the propeller. and | tearing strength and tensile strength, new rims are | On Cadillac | “Balloon | | tomobile show,. at Chi the | teresting | far only thirteen airplane . 7 : | placement known as the model W1. For ideal comfort in a Lincoln | if 4 30 | cylinders the first and second splits almost invariably are stronger and less easily torn than .are the grain leathers now generally employed. It was reported also that at least one leather manufacturer has found it possible to so cure the first and second splits as to make them as soft and pliable as the grain leathers, which heretofore have been standard for up holstery purposes and have been more care- fully treated because of the higher prices which they command. Another rather start- ling fact revealed in Mr. Herrmann’s report was that it is possible to repair cuts and grub holes in upholstery leather in such a way that the repaired portion not only is stronger than the original part, but cannot be detected on the finished side even by men with long experience in judging leather quali- ties.—Automotive Ind., 50:5, 1 p. Supercharging.—The altitude flights of Lieutenant McCready with a supercharged Liberty engine have focused public atten- tion supercharging. Supercharging simply the accomplishment of forcing more gasoline vapor into a cylinder than it could get through normal aspiration. This can be accomplished by true supercharging, which consists of forcing an additional charge of vapor into the cylinder at the end of the ex- haust stroke, or during the compression stroke of the engine, through the medium of a pump or differential piston, or, by the more usual method of forced induction which uses a blower, driving air into the mouth of the earbureter, a means of driving the blower and suitable apparatus to compensate for the additional pressure at the mouth of the earbureter, in the float chamber and the gas oline pressure line.—Rudder. on is Limousines Exeunt.—Sixteen import- ers, custom body builders and other produce ers of de luxe ears, fittings and accessories, exhibited at the annual Automobile Salon which was held simultaneously with the au sago. If bodies at the salon suggest probable trends in closed ear design, inside-drive jobs seem likely to re- place the former type of limousine. Practi- eally all the town car bodies shown were of serline type, with dropping glass parti- tion between the driver and the passengers. In many of these bodies efforts have been made to have the glass partition drop en tirely out of sight, instead of having part of the glass exposed when the window down.—Automotire Ind., 50:6, 3 pp., ill. Progress Toward 1000 Horsepower Aircraft Engines is the subject of an in- discussion of highpowered engines in Aviation (16:8, 3 pp., ill.) Numerous reports have come from abroad regarding the European development of large bombing en- gines, whereas very little information has been circulated concerning similar develop- ments at home. As a matter of fact, our Air Service has been actively engaged in the de- sign and development of large bombing en- gines ever since the war following the sign- ing of the Armistice. Records show that so engines rated not 1S |less than 600 h.p., have actually been de- signed and built. Seven are of French de- sign, three are British, two are American, and one is Italian. As far as ean be deter- mined the U. S. Air Service was therefore without any reliable engine of over 400 h.p. at the end of the war. During the following year, designs were laid down for an eighteen- cylinder W type of 2778 eu. in. piston dis- This three rows of six included angle of forty degrees between each of the _ outer rows and vertical row in the center. This arrangement of cylinders probably gives as compact an engine for the displacement as can be produced, besides having the features of perfect inertia balance, and good evenness The engine is composed of each, with an (Continued on page 342)

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May, 1924 SCIENTIFIC AMERICAN 341 Some oldtimers _ ...... service. As a tool- maker he has ac- quired a name for -working for YOU gus Frank L. Wise Forty-three years’ service. As foreman of several depart- ments, his wide knowledge has been a real contribution to the business. L. Salt. Forty- —S ars’ service. Up from the ranks —office boy to Vice- President, 1924. George E. Perlewitz. Forty-six years’ ser- vice. During all this time he has been building telephone switchboards — and building them better every year. William Miller, Forty - four years’ service. As a Cleri- cal Chief he has helped to improve ouroffice procedure. President of the Telephone Pioneers. Fred. W. Loehr. Forty-five years’ ser- vice. His long expe- rience plays no small part in the quality of Western Electric equipment. W. Merz. Forty- two years’ service, He has served as operative, as fore- man and now is As- sistant Operating Superintendent. y/~ Lewis J. Simon. Forty- three years’ service. As skilled craftsman /and ORE than forty years ago these Seeien Ts Weaenees men began their life work with Western Electric. Today they are still at it—grown skilled in the service— your service, because they produce the telephones which you use. This record is typical of Western Elec- tric workers. Here men start young, stay young and work long. Here they become expert. Here they catch the Guild spirit of the ‘Sold timers’’ and carry on that tradition of craftsmanship which has made Western Electric papal telephones the standard of the world. ' sixteen of these he has of the insulating divi- sion. No wonder he is expert! western Electric SiN ¢ E 18 6 9 MAKER §S F ES 60 vores L EQUIPMENT James Farrell. Forty- one years’ service, part of which he has been the efficient foreman of the battery room. Forty-one

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342 First of the battle- ships driven by G-E motors is the Ne w Mexico. jJaunched in 1917 What a miracle it is! Twelve years ago the United States Navy Department per- mitted General Electric engi- SCIENTIFIC AMERICAN 3 \ - ) ; x | j neers to equip the collier Jupiter with electric drive— The General Electric Company builds big turbines and motors for battleships and also makes the tiny motors that can drive so many useful ma- chines in your home The monogram G-E is a symbol of service —the initials of a friend. then a great experiment. So handsomely did the Jupiter perform that now all the great United States battle- ships are electrically driven. What a miracle it is—an in- visible current driving a 32,000-ton battleship! GENERAL ELECTRIC SSE TTA Clean Power—Dependable Power LANTS equipped with Bessemer oil- Prurning engines for industrial power are clean plants. The dirt, soot and smoke which characterize coal-burning steam power are eliminated. Then, also, fuel cil is always easily pro- curable. There is no uncertainty of supply with the attendant shutdowns. Thousands of Bessemer Oil Engine in- stallations are paying a profit to industrial users. Our engineers will be glad to show their application to your needs and point out worth-while savings in your power source. THE BESSEMER GAS ENGINE COMPANY | 14 York Street Grove City, Pa, 10072008. We Teach You How to Make It Money—bi, y—is waiting for you to come and get it. "ile man matter where you live nor what your experience, we teach you how to — money. Special preposition Fireite amazes everyone who sees it used. A single dem- onstration often makes a dozen sales. It hassaved many thousands of dollars of property damage. Men, women and chil- dren are astounded and fasci- nated bythe ease with which it puts out an alarming fire. Itis no exaggeration to state that Fireite is one of the easiest to demonstrate and fastest sell- ers ever made. Why? Because it is so simple a child can use it with one hand. tt always works — (wonderful secret composition). No pump nor mechanism. Beautiful and long lasting. The low price is within the means of everyone — 50% less than most others. Sold to every home, school, garage factory, office, store, hotel, etc., wherever shown. AGENTS AND MANAGERS WANTED in All Territory Not Taken You can make big money using all or part of your time. We supply everything for your success. This is an unusualo for asound, substantial, per- manent income. Write for our agent’ s—or manager’s —special proposition teday before it is withdrawn. FIREITE COMPANY Dept. 42 Masontown, Pa. Scientific American Digest (Continued from page 340) first one of these engines was completed near the end of 1920. The rated horsepower 7O0O at 1700 r.p.m., and 750 at 1800 was r.p.m., but the first dynamometer tests | showed a much greater output. The orig- inal engine, except for the occasional sub- | stitution of a few new parts, completed five fifty-hour endurance tests, besides other tests which probably made a total of about 300 hrs. running. Never before has the first en- gine built from any design been known to bave made such a record, nor has any en-| gine of its class been known to complete tests of equal duration. The weight of the Model W1A engine is 1770 Ibs. and, when | set to give normally 800 h.p., represents 2.21 lb./h.p. This figure is lower than any of | the six more or less successful large engines | described above with the exception of the Rolls-Royce “Condor.” Modifications, which are being tested from time to time, indicate that the weight of this engine can be re- duced to less than 1500 Ibs. without the slight- est sacrifice in life and reliability. The weight per horsepower would then be 1.87] | lb., the lowest value ever obtained for an} | smaller nyc The | than engine of over 500 h.p., exeluding of course flash readings taken on experimental engines and lower in fact than for the majority of U. S. Army Air Ser- » of the best bombing " developed, and the experience | which indicates that successful engines of | 1000 to 1500 h.p. can be built to weigh less 1.5 lb. per h.p. Air Cleaners.—If one can judge worth vice now engines yet | by increasing popularity, air cleaners have | cylinders. established for themselves a place in the sun, for they are now used as standard equip- ment on five makes of passenger car. This | has been brought about in the face of oppo-| sition on the part of car makers to any in- | crease in equipment the need for which is not abundantly proved. Rapid wear of pis- | tons, rings and cylinders has been a normal | condition in automotive engines for many years. Since dilution by fuel of crankease | oil has come to be pronounced, much of the wear has been laid to the resultant decrease in viscosity of the oil, but there is a grow- ing belief that, except under extreme con- ditions, dilution alone is not so serious as has been thought. Dilution plus dirt, es- pecially road dust containing abrasive ma- terial, undoubtedly results in rapid wear and there is not the least question that much dirt enters through the carbureter with the charge of air and fuel and is washed onto} the bearing surfaces of rings, pistons and | So pronounced is its effect in the | ease of tractors, which often must operate in | clouds of dust a large are in use, that air cleaners are |an absolute } uct, | elasticity of the final product. | cheap as those land are | described in the | process is simple, | life.—Chem. part of the time they regarded as | necessity. With passenger phos and trucks the effect is less only in degree, and since the number of hours’ use per year generally is much greater than for most tractors, the rate of wear may be just as great. It is a well known fact that so- ealled “carbon” deposits in cylinders contain | large percentages of silicon from dust in- haled by the engine. These deposits are said to be much decreased by the use of air cleaners.—Automotive Ind. Making Solid Tires from Latex.—In this method, substances that combine with or absorb water, such as calcium sulphate (calcined gypsum) and other inorganic and organie colloids are added to the latex; these substances remain in the finished prod- acting as fillers, and do not affect the During over- production and consequent cheapness of la- tex, this method is suitable for the manu- facture of solid tires, which are fully as hitherto made from rubber more durable. The procedure | patent is as follows: The mixture of latex, calcium, sulfate, sulfur and other compounding ingredients is then made up, like a batch of concrete, and spread firmly on the rim between the plates. It is then well tamped, a solid rim is attached firmly around the running ~“irface, and the latex mixture is allowed to s To improve the strength, fibrous materials can also be included in the formula. After setting, the tire is vuleanized in the usual way; then the ring is taken off, the plates are removed and the tire is ready for use. The entire it consists in a latex-ce- a latex-gypsum) treat- even menting (or, better, ment of an iron or wood rim. The solid tire thus made, however, is more durable than those hitherto manufactured, because the latex is coagulated only once, direct to the finished tire, and hence retains all its The largest selling May, 1924 quality pencil in the wor 17 Black Degrees 3 Copying To insure utmost satisfaction, efficiency and economy, always use VENUS PENCILS. Plain Ends, per doz. . . . . $1.00 Rubber Ends, per doz. . $1.20 At Stationers, Druggists and Stores throughout the world American Lead Pencil Co. 217 Fifth Ave., New York Send 10c for a sai Venus Penciland =“ a Venus Eraser: hk degree desired. For bold, heavy lines . 6B-5B-4B-3B For writing and sketching . 2B-B-HB-F-H For clean, fine lines . H-3H-4H-5H-6H For delicate, thin lines . 7H-8H-9H Name Address Accuracy Guaranteed Compact Stands Hard nocks SANBORN BLOOD PRESSURE OUTFIT Both Doctors and Patients can get accu- rate readings with this new 1924 Sanborn Blood Pressure Outfit, fully guaranteed. Watchface ithetand non-leak release "Comm built to w it hard | ‘om- pact, p 2 A leath Also, ee booklet on Blood Pressure Tests. From Manufacturer to User—Price $20 Write for Description ANBORN DIAGNOSTIC APPARATUS ||| 1048 Commonwealth Ave., Boston, Mass. HHH HU and Metal. Eng. Here is good news for the Deaf or people whoare hard of hear- ing. Science has at last triumphed we over deafness. Unless your Audi- y tory Nerve is entirely Setocees, the Acousticon will enable you to hear as perfectly as anyone whose hearing is normal. Thousands who have been Deaf for years report most gratifying results—many say they can hear the slightest whis and that their natural hearing has been greatly improved. We have testimonials from Governors Bankers, Ministers, Lawyers and thousands of others. j_. great is our confidence that we invite every sufferer to Try It 10 Days FREE You are not asked to purchase this remarkable invention until 7 have tried it 10 days FREE, until you have proved to your entire satisfaction that it is what you need and want—until you are absolutely certain that it will enable you to hear all sounds clearly. Then, if you wish, you may keep and pay for it, otherwise return it and there will be no charge. Send No Mone We ask for nodeposit. We do not shipC. O. D. send you this latest scientific invention soticely at our own risk and expense for 10 days FREE TRIAL. don’t ask you to pay first and then refund your money we you are not satisfied. We send you the Acousticon with- out cost or obligation. It must prove its own merits to mee entire satisfaction, Unless you are amazed and de- ighted with i oe are not asked to purchase. When we om FREE we mean FREE TRIAL, sosend name address Zz _ for pane sc only literature, testimon- ials end FREE TRIAL request Dictograph Prodtcts Corporation 1302Y Candler Bidg., 220W. 42ndSt., New York ing tul in to me ste: ope pra elec stal test and tem side vert elec ap fror was was fere plac nect To arou shaf surf. shaf a h Afte offer men cap woul blast of th Coal Sh Indu the | on a Elect whee! wheel on tl 13.00 ner, the s avail by me therec placec the p nectec

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May, 1924 Civil Engineering Why Italian Dam Failed.—On Dec. 1,| 1923, a 143-ft. power dam at Gleno, Italy, | failed suddenly. Great destruction was done | by the escaping waters along the valley of | the Dezzo River in the 12-mile length down | to its junction with the Oglio River at Darfo. | The Dezzo Valley is steep and narrow, and in places the flood wave reached a depth of 100 ft. The loss of life is estimated at 500. The dam, only recently completed, was | a reinforced-eoncrete structure of multiple- arch type resting on a gravity base of eal masonry. It was 1438 ft. high above the stream, 863 ft. long on top, and of eurved ground plan, comprising a circular central portion about 250 ft. long and straight end | portions, tangent to the central curve. The} reservoir back of the dam was of about 4400 | acre-ft., or 190,000,000 eu. ft. capacity. The | location is high up in the mountains, the} highest reservoir level being about 5200 ft. above sea level, while Darfo is at 820 ft. No precise statement of the conditions leading up to the break of the dam can be given be- fore the official inquiry is completed. Certain facts are fairly well established, however. On the authority of a competent engineer of dams who visited the Gleno structure re- peatedly, it may be stated that the work was badly executed. The masonry of the gravity base was laid up in lime mortar, of lime burned near the site by the builders and transported to the dam by cableway. The specifications called for cement mortar. The gravel aggregate used in the concrete was not washed, and the concrete in the structure was porous. The reinforcement of the buttresses was scrap netting used dur- ing the war for protection against hand grenades. This same engineer stated that during construction one of the arches leaked, where a centering timber that projected into the concrete had been cut off flush with the face of the work. The reinforced-concrete parts of the dam on either side of the masonry base were placed directly on the rock surface, without being trenched into the rock, leaving its end embedded in the concrete. Eland-mixed concrete was used, and the usual precaution of ramming it in the forms was omitted.—Hng. News-Record 92 :5, 3 pp., ill. Electrical Ground Currents from electric hoist-, ing equipment were the cause of a prema- | ture explosion during the sinking of a shaft in West Virginia, which pearly proved fatal to the workmen employed. Some of the men refused to work in the shaft unless steam was used in place of electricity for operating the hoist and pumps. This was practically out of the question, since the electric equipment had already been in stalled. It was decided, therefore, to make tests to determine the cause of the explosion and to decide upon the remedy. The sys tem used for power was grounded on one side and supplied by a 1000-kw. rotary con- verter. While the switches were open, an | electric blasting cap was connected between | a pipe in the air line and the discharge line | from the pumps. The instant a connection was made, the blasting cap detonated. It was evident that there was a sufficient dif- ference of potential present in the various places selected to fire blasting caps con- nected in an ordinary circuit in the shaft. To equalize the voltage at various points around the surface and at the bottom of the shaft, the frames of all the machines on the surface and the pump at the bottom of the shaft were metallieally interconnected with a heavy copper conductor and grounded. After this work was completed $25 was} offered to some of the most intelligent work- men if they could fire an electric blasting cap by connecting it in any way that it would explode, without, of course, using a | blasting machine or the power circuit. None | of them was able to fire a cap in this way.— Coal Age, 25:7, 1 p., ill. | Shrink-fitting a Large Waterwheel by | Induction was an interesting solution of | the problem of expanding the bucket runner | on a 9500 horsepower unit as described in | Elect. World. The over-all diameter of the | wheel was 7 ft. 4 in., the diameter of the wheel center 4 ft. 7 in. and the length of fit on the shaft 18 in., with step fit of bores 13.006 in. and 12.996 in. in the present run- | ner. The new wheel was put in place on the shaft in the following manner: Using available bare stranded wire and insulating by means of sheet and tape asbestos wrapped thereon as required, there were 39 turns | placed around the hub and 54 turns around the periphery. These windings were con- nected in series and supplied with 60-cycle SCIENTIFIC AMERICAN Where Jones Enclosed Speed Reducers are used In mills, factories, mines, quarries, ware- houses, and many other places Jones Enclosed Speed Reducers are giving con- stant satisfaction. In almost any case where driven machines oper- ate at a lower speed than the electric motors, enclosed speed reducers can be used. For driving Elevators Mixers Tables Car Hauls Conveyors Cookers Fans Pumps Feeders Screens Dryers Hoists Agitators Stokers Crushers Gas Producers their superior performance and greater economy over old fashioned methods of speed reduction is an acknowledged fact. If you would like to know just what advantages you can obtain by using Jones Spur or Worm Gear Speed Reducers, write us. Our engineering staff is at your service—without obligation. Or, if you prefer, ask for our book on the modern way to reduce motor speed. It is easy to read, technically accurate, well illustrated—and will interest you. W. A. Jones Foundry & Machine Company Main Office and Works: 4407 West Roosevelt Road, Chicago Branch Sales and Engineering Offices: New York Pittsburgh Cleveland Buffalo Milwaukee Church and Murray Sts. Union Trust Bldg. 226 Superior Ave., N.W. 184 Main St. 425 E. Water St. Combination Jones Spur and Worm Gear Speed Reducers driving As- sembly Conveyor. Motor speed 720 R.P.M. Final speed 0.185 R. P.M. Transmission Service N addition to spur and worm gear speed re- ducers, we manufacture a complete line of power transmission appliances— hangers, pulleys, coup- lings, pillow blocks, fric- tion clutches,ball-bearing loose pulleys, safety col- lars, etc. The service of our en- gineers is at your com- mand. Their experience may prove very helpful. We will be glad to have you write us. - Jones Speed Reducers and Power Transmission Appliances

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344 SCIENTIFIC AMERICAN | | ¥ One Ton or a Shovelful ? One man can raise a ton with the Godfrey Con- veyor and not exert a fraction of the energy required to lift a shovelful of coal. | alternating current through a regulating rheo- stat from a 3714-kva., 220-volt single-phase | in place on the hub. One man can unload and store a carload of coal in an hour and a half with the Godfrey Conveyor at a cost of from three to seven cents a ton. When you realize that you can install a Godfrey Conveyor at no greater cost than the price of a good truck, you will want to know more about this equip- ment. Ask for Bulletin A-23. GODFREY CONVEYOR COMPANY Elkhart, Indiana Investigate SPRACO Industrial Finishing Equipment Greater Speed, Finer Finish, at Lower Cost For years we have been Saves the work of 3—5 men. SPRACO is the clean, healthful, scientifically correct method of applying decorative or protective coatings to a manufactured com- modity. making a specialty of equip ment suited to the exacting requirements of this type of work. Let us send you our + free booklet,-~and other in formation which may be of Finish-wise and economy-wise SPRACO equipment is more highly productive of Satisfactory Results than any other. We also manufacture port- able painting outfits for all kinds of structaral and broad surface work,—inte- riors and exteriors. Spray Painting and Finishing Equipment Sales Co. Distributors for SPRAY ENGINEERING CO. 60 High St. Boston, Mass. Write Dept. P-70 | | | | with an observer's cockpit in the floor of | which an opening was provided for sighting | the camera. The camera made a_ picture transformer. The potential across the coils May, 1924 ————E_ Lees was approximately 103 volts and the cur- rent varied from about 135 amp. to 150 amp. During the heating the wheel was suspended from the crane and was boxed in to assist in maintaining a uniform tempera- ture throughout. Thermometers were placed so that the temperatures of the rim, hub, interior of the box and room could be ob- served. Upon applying the current it was seen that the hub temperature increased so much more rapidly than the rim tempera- ture that it was advisable to bring up the temperature gradually by applying current for a few minutes at a time, allowing the heat to distribute within the box during the intervening few minutes. By this process the temperature of the wheel was raised gradually during a period of about 27 hours, when the box was removed from the wheel, leaving the current on until the wheel was By means of this heat- ing the inside diameter of the hub was in- | creased 0.015 in. At the same time ith shaft was inclosed with a box packed with ice between the bearing and the wheel loeca- tion, resulting in a reduction in its diameter of about 0.001 in. The wheel was readily pulled into place with two rope tackle blocks one on each side, moving the crane mean- | while. The current was then cut off and the wheel allowed to cool. Rust-Resisting Copper Steel KEYSTONE 4) - °PpeR stek Black and Galvanized Formed Roofing Products Roofing Terne Plates Tin Plate, Etc. Secure maximum rust-resistance from all sheet Transmission Line Work Aided by metal products by insisting upon copper-steel. Aerial Survey is the subject of a descrip- | Its excellence is a well established metallurgical tion of a new use for the airplane, contained fact. The proof is conclusive. in Eng. News-Record (92:9, 4 pp., iil.) sion transmission lines, 25 and 30 miles in ner of Pennsylvania. : ’ | Keysrone Copper Sree is an alloy made by the addi- | Aerial photography was employed to facili-| tion of a certain percentage of pper to well made | tate the rapid completion of two high-ten- | Steel, thereby increasing its lasting and rust-resisting qualities under actual service condition. Unexcelled for ; , culverts, tanks, flumes, roofing, a er. spouting, length, respectively, in the southeastern Cor-| and all exposed sheet metal work. The photography for | giving results of positive time and service tests. nd for booklet the lines under diseussion consisted of con- | We manufacture Sheet and Tin Mill products for all pur- tact lines and complete strip maps, with special stereoscopic views taken of some of oses- American Bessemer Steel Sheets, American Open earth Steel Sheets, Keystone Copper Steel Sheets, Black Sheets, Special Sheets for stamping, Sheets for the towns and of some properties to assist | Electrical apparatus, Automobile Sheets, Deep Drawing in obtaining right-of-way privileges. The | Sheets; Apollo and Apollo-Keystone Galvanized Sheets, : ; o , Corrugated Sheets, Formed Roofing and Siding Products, average flying elevation was 12,000 ft. and | Culvert and Flume Stock; Long erne Sheets, Roof- the maps were finished on the seale of 1000 | ing Terne Plates, Bright Tin Plate. Black Plate, Etc. ft. to the inch. a ground area of about one and one-half by two miles. There were in the neighbor- hood of 500 single photographs taken for the line strips. A standard biplane driven | A single photograph showed | ,wepicaN SHEET AND TIN PLATE COMPANY, Pittsburgh, Pa. by a 150-h.p. motor and capable in calm | air of a 6-hour flight at 60 miles an hour was employed in the flying. It was equipped about 7 by 9% in. in size and used a roll | film containing about 100 exposures. This | brings us down to the point where use of the aerial photographie data actually began. The contact prints were studied in connec- tion with the quadrangle maps and a line location laid out on the prints according to the most desirable possibilities of avoiding obstructions, high-priced land, and construe- tion difficulties; also with the idea of acces- sibility during construction and for future maintenance. The prints were then put in the hands of the men securing right-of-way options. With their help the right-of-way agents located themselves at once on the} proposed route and after a little inquiry | determined the names of the property own- ers, which were given to the men making searches for descriptions of properties. As fast as descriptions were obtained from the county reeords the property outlines and owners’ names were inked on the _ prints. When surveying parties were sent out to establish the final alignment and to deter- mine the profile of the route they carried into the field the mosaies with the line route and property lines marked on them, and | used them throughout the survey. | Industrial Progress A New Casting Process is described in Automotive Ind. (50:5, % p.) By this process, iron castings are molded and poured | with the expenditure of about one-eighth | of the man-hours required by the sand-| casting methods. In addition to this feature | the surface hardness which is always pres- ent in sand-molded castings is absent in the permanent-molded castings. The iron is much closer grained, soft and easily machin- able and uniform throughout. The process, which was discussed in Automotive Indus- tries of November 1, involves a turntable which carries twelve permanent split-type molds. The molds are cast iron, being | treated when cast so that the interior sur- | faces are highly refractory. In operation, PATENTS If you have an invention which you desire to protect we shall be pleased to have you consult us. Our booklet giving information on patent procedure will be sent upon request. Scientific American is the monthly news-reporter on all the big indus- trial and scientific developments, inventions and scientific discov - eries. Plainly written, easily un derstood, accurate and interesting. MUNN & CO. PATENT ATTORNEYS Woolworth Building - - - - New York City Scientific American Bldg., Washington, D.C Tower Building - - - - - - - Chicago, Ill. Hobart Building - - San Francisco, Cal. Van Nuys Building - - - - Los Angeles, Cal. RACINE DUPLEX BAND SAW Another Racine cutting machine that will save you time and material Saws anything — wood, soft metal, or steel. Easy to locate where you want it. Vibrationless, ball-bearing mounted wheels assure great accuracy — bla last many times longer. A demonstration will con- vince you. Use “Racine” H. S. Wood and Metal Band SawBladesand’‘Racine™” H. S. Tung- sten Power and Hand Hack Saw lades. There is a Racine H. . metal cutting ma- chine for every requirement. Write for literature RACINE TOOL & MACHINE CO Dept. B_ Racine, Wis., U.S.A. “STANDARD THE WORLD OVER” the working surface of the molds are first m in wi in m we O1 pl: ess pli the ins di: ha diz the bee im tai boi kilt ma to bee whi plai ho cus hea bee! the of ady mat that pro ably ing, mor duce Neu T yout ily. use State afte cons! peciz day, consi barn. ings. is in ets. conel inche avere is sor the d devel same large speed ton si men | is mu

Page 45

May, 1924 coated with amorphous carbon by an acety- | lene flame. At the next station the dry | sand core is set in one half. The mold then | closes and continues around to the pouring station, where one man pours the iron from | a small ladle. Next the mold opens auto- matically, the casting is knocked out and the mold is blown out by an air stream, ready for the repetition of the cycle. High silicon iron is used and the carbon coating in the interior of the mold reduces the melting point and retards the cooling rate so that the casting forms before the con- traction of cooling takes place. The rate and total amount of construction is only about one-fifth of that of the sand casting | process. As the surface of the mold is highly refractory and coated with carbon, the heat of the incoming metal is conserved and not lost to the mold, which condition causes surface chilling and slower flow. This process is now in operation on Holley earbureter bodies and Ford pistons. About 2500 pistons are produced per day per ma- chine. Experiments have been made with the pouring of malleable iron and _ several non-ferrous metals with very good success. Steel castings can be made by this method providing complicated castings have some cores. The process is not limited to opera- tions on small eastings but is even better suited to the production of large castings. | Iron castings weighing about 25 Ibs. have} been produced with every degree of success. Modern Trend in Building Cement Mills.—A development of recent years in the manufacture of Portland cement has | been the increasing use of large crushing | plants for the preliminary reduction of the rock. There has been much recent discus sion in regard to the relative merits of the wet process and the dry process of cement manufacture. Unmistakably the trend dur ing the past five years has been toward the wet process. During this time, of 19 plants in the United States constructed or for which machinery contracts have been placed, 17 were designed to operate by the wet process. Of the two remaining, while a new plant, is an addition to an existing dry proce plant. Of several new plants contem plated, all or nearly all are to operate by the wet process. Most modern plants have installed kilns from 10 feet to 11 feet in diameter. Two plants in the United States have successfully operated kilns 12 feet in diameter for several years. The limit of the kiln diameter, however, seems to have been reached until a better refractory or an improved method of holding lining is ob Css tained. Until the introduction of waste heat boilers, the tendency was toward longer kilns; but since low temperature kiln gases make the cost of boilers high in proportion to steam produced, the recent practice has been to limit the length from 150 to 175 feet when boilers are Some wet plants have installed kilns 240 ft. long, but no practicable length of kiln will reduce the gases to so low a temperature as a waste heat boiler and economizer. While there have used. process material used in construction, it is probable that the next ten years will see equal im- provements. These improvements will prob- | ably consist largely of more efficient grind- ing, better economy in fuel consumption, more economical use of waste heat and re- duced labor and Eng. | News, 36:2, | been many important improvements during | the past ten years, which permit the sale | of Portland cement at a_ relatively lower | advance in price than almost any other | } | charges.—Cement 3 pp., ill. The Concrete Stave is a comparatively | youthful member of the building unit fam- | ily. Invented less than 20 years ago, its use has been extended to practically every | state and community in the country. Soon | afterward concrete staves were used in silo construction, their shape making them pecially suitable for cireular structures. day, concrete staves are also used in construction of grain bins, coal pockets, | barns, hog houses, garages and other build- | ings. Their most extensive however, | is in the construction of silos and coal pock- | ets. In general, the concrete stave is a| concrete slab about 30 inches long, 10 inches wide and 2% inches thick. The| average weight is around 70 pounds. There | is some variation in width and length among | the different types of staves that have been | | es- To- | use, developed. Practically all types are of the same thickness. Since the staves are rather | large and are set up without mortar, rapid | speed of construction is possible. A 100 ton silo can ordinarily be completed by three | men in two and one-half days’ time. This | is much quicker than for any other type of SCIENTIFIC AMERICAN 345 IN THE PLANT OF C.G. CONN the le LTD. ELKHART, IND. é& Dodge ‘Transmits Power to Build Instruments for the Masters From a tiny workshop, employing one crude lathe improvised from a sewing machine, through three devastating fires, C. G. Conn, Ltd., has grown to the large plant shown above manufacturing band and orchestra instruments. 180,000 feet of floor space is overhung with Dodge Power Transmitting Machinery, including pulleys, hangers Dodge Units Withstand Fire and Water Some of the Dodge equipment in use today in the Conn factories went through at least one of the devastat- ing fires which reduced three Conn plants to ruins. Salvaged from the ruins, Dodge hangers, pulleys and shafting were again pressed into ser- vice, while Dodge engineers worked tirelessly to assist in re-establishing production schedules. clutches, etc. Conn specifies Dodge Power Transmitting Equipment because Dodge represents to Conn what Conn represents to the master musician. Dodge means power savings. Three large factory warehouses and four- teen branch warehouses supply 500 local dealers who supply Dodge power transmitting appliances on the immediate delivery basis. DQG@DGE DODGE MANUFACTURING CORPORATION General Offices: Mishawaka, Indiana Works: Mishawaka, Ind., and Oneida, N.Y. 7 EVERYTHING FOR THE MECHANICAL TRANSMISSION OF Branches: New York ~ Adanta Philadelphia Minneapolis Pittsburgh St. Louis Boston Newark Houston Cincinnati Seattle Chicago San Francisco Powe" When Peadestion ‘Must Be Increased When the Board of Directors authorizes immediate extension of facilities to increase production the executives responsible for the execution of the plans are faced imme- diately with many problems. Orders for machinery must be placed, the power plant must be re-arranged, the power roadbed or transmitting system must be expanded. Delivery is all important. The increased power demands may mean many things. New flywheels, rope sheaves, hundreds of hangers, pulleys, couplings, collars and couplings. Centralization of purchases means time saving andeconomy. The manufacturers possessing facilities for supplying all stock appliances such as pulleys, hangers, etc., as well as special built-to-order flywheels and special equip- ment other than power transmitting equip- ment is in an enviable position to serve when prompt execution of increased pro- duction programs is imperative. The Dodge Manufacturing Corporation has sustained their reputation for rendering emergency service to industry for over forty years. Extensive engineering, foundry and ma- chine shop facilities are at the immediate command of manufacturers for the produc- tion of large flywheels up to 50 tons, huge pillow blocks, special bearings and buil!t- to-order power transmitting equipment. In the Dodge shops thousands of tons of equipment, such as complete piercing mills, | plate glass polishing tables, etc., are pro- duced yearly. Facilities for the design and manufac- ture of agitators, cement mill machinery, crushers, oil mill and oil well equipment, rubber mill machinery, etc., are available. In addition, and of prime importance ’to the executive faced with the problem of securing almost immediate delivery of large quantities of stock power transmitting units, is the three large factory stocks, five hundred local dealer stocks and fourteen branch warehouses placed at strategic points throughout the country ready to ship pulleys, hangers, pillow blocks, couplings, clutches, etc., at a moment's notice. In Chicago a stone’s throw from the Chicago Junction Railroad Freight Sta- tion, is a large factory stock of Dodge products available for shipment by pack- age car. Over 2,500 of these cars leave Chicago daily over 39 railroads. Dodge facilities for manufacture and immediate delivery have kept pace with industrial progress and will always main- tain a position of leadership in the important business of aiding industrial expansion.

Page 46

SCIENTIFIC

week end

Move chassis and body, result of Temperature, properly controlled. Just as carefully watches his patient’s temperature modern manufacturer watch his For three-quarters of Taylor Instrument Companies than ull other manufacturers together. Tycos instruments 1 longer record of dependable service than any other employee. Taylor Instrument Companies ROCHESTER, N. Y., 's a Trees or Thr Thermometer for ev

TheRoot Co., Bristol, Conn.

AMERICAN masonry silo. The necessary skill required to set up the staves is easily and quickly acquired by the average man with some mechanieal ability. Soon after the advent of the silo type of coal pocket, these struc- tures were built of concrete staves. Coal pockets are almost identical in construction | to silos except that they are usually larger | and are more heavily reinforced to resist the greater pressure of coal.—Cement and | Eng. News, 36:2, 4 pp., ill. The Federal Specifications Board has | completed the second year of its activity. In} this, the American Engineering Standards | Committee has co-operated by obtaining criticisms from the various interested indus- tries of proposed specifications of the Fed- | eral Government before the specifications are | finally adopted by the board. To date the board has adopted approximately 90 speci- | fications, and the committee has secured criticism of industry on about the same num- | ber. From these systematic efforts to bring governmental purchases in line with the best commercial practice, important economies both to industry and government are re

MAY, 1924

L il j

Lr wast. | ae 2 oe oy eS

| i ‘ ;

sulting—Am. Gas Jour. “Best Ventilated ue hoe

Mechanical Engineering A New Non-torsional Spring.—In springs of all usual designs, the material is subjected to bending or torsion and their eapacity is limited to their volume. Any increase in their capacity to absorb energy can be obtained only by means of a corres ponding increase in volume, which is, how ever, frequently impossible due to lack of available space. A change in the nature of the stresses to which the material is sub jected is frequently the only way whereby such an increase in capacity can be obtained. Due to the fact that pure tension and com pression stresses lead to a far more complete utilization of the material, spring experts have for a long time been trying to design a spring in which only such stresses occur. These efforts have finally led to the invention of the ring spring, the first design in which all parts are uniformly subjected to tension or compression stresses. The spring consists | of inner and outer solid rings which fit into each other along conical surfaces. When axial pressure is applied the outer rings are subjected to tensile stresses and the inner rings to compression stresses, always within the elastic limit of the material. On ae- —and why he said it That’s what the manager of a big motor repair shop said about Valley Motors. This ventilation is gained by the exten- sion of the copper rotor bars on both sides of the rotor. Air is drawn into the motor through the end plates by the extended rotor bars which act as fans. The cooling air currents are forced over the winding and stator laminations and driven out through vents in the frame. Good ventilation means low tempera- ture rise. And low temperature rise in a motor prolongs life. Valley polyphase motors are made in sizes from '4 to 40 h.p. Valley single phase motors are made in sizes from 1% to 5 h. p. Write for Bulletin No. 8-22. It describes all details of Valley design and construction. VALLEY ELECTRIC COMPANY 3157 S. Kingshighway, St. Louis, Mo. Representatives in Principal Cities leyMotor

count of the deformation of the rings which

occurs, they slip into each other and a spring action in the direction of the longitudinal axis of the spring is obtained. An impor tant feature is that the relative motion of the rings is also opposed by a considerable friction between the conical surfaces, which materially increases the spring reaction dur- ing compression and exerts a_ retarding action during the recoil at release. This}

GEARS All HKinds-Small The most accurate made and prices reasonable. We carry a complete line of gears in stock for immediate shipment. Can also quote on special gears of all kinds. Send us your in- quirie Write for Catalogue 20 CHICAGO STOCK GEAR WORKS 105 South Jefferson Street Chicago

property is of particular value in all devices where a great amount of energy must be accumulated and, as far as possible, con- sumed.—Am. Machinist, 60:7, 2 pp., ill. What is the Water Circulation in a Boiler? —Ask yourself this question and see how near your answer approaches the real facts as here outlined. The wide diver- | gence in opinion as well as the lack of actual | information possessed by even those concedede to be the “knowing ones” in boiler design, was strikingly brought out in a contest. Un- der the terms of the contest the engineer who deseribed correctly the circulation in the horizontal return-tubular boiler was to be awarded a prize. Hundreds of engineers and engineering associations entered the con test, and the variety in answers almost equalled the number of contestants. <A local of the National Association of Stationary IXngineers won the prize, the answer, which was a composite of its members’ opinions, being practically correct. Incidentally, some of the members actually constructed a glass model of the boiler before submitting their answer, and so were playing a “sure4 shot.” Examination of the glass model shows that the water and steam mixture rises up along the front head at a high ve- locity, and after releasing the steam bubbles, the water moves toward the rear until it reaches a point a little beyond the center of the boiler, whereupon it drops downward. Upon reaching the lower part of the boiler, the main part of the stream turns toward the boiler front, while a part flows toward the rear. There is a secondary steaming | zone at the rear head, causing an upward flow, the current then flowing toward the | front and downward, making a loop. These | two actions cause the circulation of the | water to be in the form of a figure 8 placed | horizontally.—Power, 59:8, 2 pp., ill.

cording to size. TRIPLEX Combination Bench Lathe, Milling and Drilling Machine The IDEAL Machine for Experimental Work Send for Circulars Manufactured by B. C. AMES CO. LEXINGTON STREET WALTHAM -t-

LATHES 9 to 18-inch Swing List price $115 and « we ac- hen ready to buy send for Lathe Catalog and prices. W.F.& John Barnes Co. 1999 Ruby St., ROCKFORD, ILL.

pe di th fii be du bit pa oil aff hit tal for gir to ail me ber nul fiel fiir shi fiel of cou and and nal I in rest cop Chi first tic tion for per. prov tot nica tials pris and that mies no 0 for : tons of o tons V7.1 18,0 expe had per woul proe avail if th tion balke searc ened other on tl of ul or bo ing 1 ing a ducti torial He cial mer samp repre

Page 47

May, 1924 SCIENTIFIC AMERICAN 347 General | Zirconium has an gy awe 4 high | melting point, above 4000 degrees Fahren- heit, and it is not attacked by the strongest | acids. The perfection of zirconium steel has | not yet been reached, but the highest qual- ity of zirconium tool alloy is in daily use in this and other countries. In the manufacture of white sanitary ware, bathtubs, toilets, cooking utensils, hospital ware, washstands, in fact, in every known form of white enamel ware, zirconium is now being used as the material that gives the white color and glaze which resists the action of acids, of disease germs, and the corrosion of decaying matter. In making electric porcelains zircon is one of | the best materials. In airplane and automo- bile spark plugs, wireless telegraph insula tors, high-tension transmission insulators, and for similar uses, it is of the greatest value. It plays an important part wherever either high temperature or high voltages, or both, have to be withstood. These qualities also make it desirable as a refractory, in fire-brick furnace-linings, retorts, crucibles, and ladles.— Mfr's. Record, 85:8, 5 pp., ill. Hugo Stinnes, the German Industrial Baron.—The concentration of German in- dustry goes on. A few weeks ago a new German oil trust was promoted by Hugo Stinnes. He combined three important petroleum producers of Germany under his direetion: The Riebeck’sche Montanwerke, the Aktiengesellschaft fiir Seeschiffahrt und Ueberseehandel, and the Aktiengesellschaft fiir Petroleumindustrie (Api). The Rie- beck’sche Montanwerke are important pro ducers of mineral oils and paraflin from é : 7 . bituminous lignites. In 1921-22 this com t pany produced 26,600 metric tons of mineral Electric motor users find distinc oils, and 9700 metrie tons of candles, par affin, and mineral wax. The output of lig- ete tom, Te AD a advantages i in motors equipped with Strom Ball Bearings gin patents, methods which make it possible to liquefy coals into oils. For this purpose a modern plant with a capacity of 100,000 metric tons yearly was built near Heidel- berg. The company controls also a great number of refineries, storage plants, and oil Siar Manadiiches te Wlcesene cantare eatie Uninterrupted service of greater than the running fiir Seeschiffahrt in Hamburg possesses tank- : : ships, storage, and distribution plants, oil electric motors is insured resistance. fields in Argentina, and controls a number) Double-acting thrust GF SE LY 7 ee re of trading companies. Thus this new trust >¢aring. fat sears by eles a Maintenance and service combines the production of coal, lignite, oil, 2100-F Series troubles caused by oil leak- RA : and the refining and distribution of its own : y costs are lowered. and other products.—Hng. and Min. Jour- age. : A uniform air gap between Housings are designed for armature and coils is main- the retention of lubricant, tained, because the wear of thus preventing its escape pall bearings is negligible. and entrance on to the in- nal Press. Benefits of Moral Support and Capital in Research.—The economies that have resulted from the introduction of the new copper-silicon anodes at Chuquicamata, Chile, are such that it may be said that the first phase in the development of that gigan- h y tic enterprise has been passed—the perfec- Singie-acting thrust sulation. More compact motor de- Hiegone tion of cheap and efficient technical methods (grooved races) sign is permitted because poy for the extraction and recovery of the cop- 1100-F Series M a ° 1 1 a a : type, tatiel bearing per. The history of the Chile Copper Co. Motors require onlyasmall of small bearing width , , provides many lessons of deep significance f > . . : to the capitalist, as well as to the non-tech- amount of lubricant. space required. nical observer. It shows that the essen- tials needed for successful achievement com- prise unhampered research, adequate capital, and moral support. It is interesting to note that improvements in technology and econo- mies of operation have been steady but by There is a marked reduc- End motion of rotor in tion of friction, thereby re- the field is eliminated, be- ducing starting and run- cause STROM Ball Bear- no means rapid. In 1915 the plant operated | Single-acting, self- ning resistance. In fact,the ings take end thrust as well for seven and one-half months, and 625,594 ae st ino -sistance is aS dial load ‘ agit gaalbeagcr Tegan : yearing arting resistance 1S no. aS radial load, tons of ore was treated, with an extraction | 1100 Series 5 Angular contact of only 66.87 per cent. In 1916, 1,742,748 | bearing, combination tons was treated, with an extraction of only radial and thrust 77.15 per cent; and it was not until about 18,000,000 tons had been treated and an experience extending over five years or so had been gained that an extraction of 90 per cent was achieved. One wonders what would have happened to the Chuquicamata process if it had not been backed by the availability and influence of ample capital; | STROM Ball Bearings are made in a wide range of types and sizes for practically any installation in automotive and machinery fields. Our engineers will be glad to assist in the selection of bearings and in the de- sign of their mountings. : . : Single-acting, self- if those who were responsible for the incep- ~ elkneteer Ghavent tion of the plan had been systematically bearing, leveling balked in their demands for adequate re-| W#Sher. 1100-U Series D — cee maxt~ search; and if enthusiasm had been damp- : wig type, ened at the outset and eapital diverted in radia! bearing other direction by a verdict based entirely Ca > on the opinions of those who were sceptical | = a of ultimate success, or envious of initiative, | A 7 a or both—a verdict that took account of noth- ‘ : ’ ing more than the poor metallurgical show- ing and the comparatively high cost of pro- | duction at the outset of operations.—Zdi- torial in Eng. and Min. Jour.-Press. How Much Ash Is Found in Commer- | pie cial Anthracite?—During the past sum- pay ne a U. S. BALL BEARING MFG. CO. mer the U. S. Bureau of Mines took 127 Sep nag theme [ samples of anthracite, each of 1000 pounds, are 4583 Palmer Street a representing nearly 30,000 tons of such coal | 2100-U Series CHICAGO, U.S.A, radia! bearing Manufactured by

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348 SCIENTIFIC AMERICAN What Comfort-Lovers Say No. 743 18.000 Miles 45 Miles an hour There are thousands of such letters in our files “S “CINCE installing Hoo-Dyes on my Pierce-Arrow, I have driven the car 18,565 miles. A good deal of this driving was done at forty-five miles an hour over extremely rough toads between Northern Michigan and New York. “The shock absorbers have given excellent service “ironing out” the irregularities of the road and making the car an exceptionally easy riding one. In my experience I have used three other types of shock absorbers but I have found HOO- DYES by far the most satisfactory, from a constructive, op- erating and every other point of view.” From the Vice-President of one of America’s great copper concerns. ame and address on request SAFETY WITH HOO-DYES The car that is equipped with Hoo-Dyes is a safe car. It is safe because the double-acting, hydraulic shock absorber prevents pitch and side-sway; it is safe because all four wheels are held on the ground no matter how great the speed; it tends to prevent skidding on rough roads even if the brakes are applied for an emergency stop. The Hoo-Dye hydraulic control, which transmits every axle movement directly to the liquid cushions by means of a drop-forged, double-acting connecting-rod, brings to motorists a marvel- ous sense of security combined with supreme riding comfort. THE HOUDAILLE COMPANY, 1458 West Ave., Buffalo, N. Y. Manufactured by Houde Eng. Corp, HOO-DYTE Double-Acting Hydraulic Shock Absorber Remarkable qualities that may improve your product ORMICA in electrical and mechanical ap- plications is serving many purposes better than was possible until just recently. It combines the highest dielectric strength with high tensile strength; it has a low phase angle and extremely low power and hysteresis losses in high frequency work; it does not absorb mois- ture and is not affected by oil or chemicals of any kind; it will not warp, sag or cold flow, nor change its color. It is used for silent elastic gears in automobile timing trains, and for industrial purposes. Its strength is similar to cast iron, but its wearing qualities are greater. As radio and electric insulation, for pump valves, gears, washers’ bushings of all kinds its use is expanding at an amazing rate. Perhaps it will solve a difficult material problem for you. Write for booklet ‘“What Formica Is.” Note: Replacement automobile timing gears of Formica are sold by the Perfection Gear Company, Chicago. THE FORMICA INSULATION COMPANY 4645 Spring Grove Avenue, Cincinnati, Ohio ORMICA Made from Anhydrous Bakelite Resins SHEETS TUBES RODS | in dealers’ yards in seventeen cities in the State of Massachusetts. There were three objects in view: To discover the average and the variation in the quantity of ash in anthracite in some easily described area; to demonstrate standard sampling methods and | to learn something about the feasibility of | itinerant coal sampling. The weighted aver- | age ash content was: For furnace size, 13.2 per cent; egg, 13.7; stove, 13.7; chestnut, 16.2; pea, 15.6; range, 19; buckwheat No. 1, 18.9 per cent. In the eight samples of | furnace coal the lowest ash was 10.5 per cent and the highest 14.6 per cent; of 29 samples of egg the range was from 10.2 to 17.5 per cent; of 20 samples of stove coal, 11.3 to 15.9 per cent; of 23 samples of chestnut, 10.3 to 46.1 per cent; of 20 samples of pea, 12 to 27.3 per cent; of four samples of range, 13.1 to 28 per cent; of eight samples of No. 1 buckwheat, from 13.6 to 29.5 per cent. In the chestnut coal the highest six samples ran 46.1, 40.7, 28.3, 25.6, 18 and 16.5 per cent ash. The six cleanest samples ran 10.3, 12.2, 12.9, 13, 13.2 and 13.4 per cent ash. The coal producer judges the quality of the coal by taking a small sample and by hand separating it into three piles, one of coal, one of bone and one of slate. A piece which he guesses has less than 40 per cent ash would be called coal, a piece having from 40 to 65 per cent ash would be called bone, and anything having a larger amount of unburnable material would be called slate. The figures obtained by this survey give an idea of the actual quantity of ash in anthracite sent to one district in the summer of 1923, when the opinion of dealers was that the quality of the coal in general was good.—Coal Age, 25 :8, 1 p. Another Attack on the Cotton Boll Weevil has been made by a Georgia grower. By increasing the thickness of the hull of the cotton boll through a process of breeding extending over ten years, J. V Cochran, of Marietta, Georgia, has produced a cotton that practically defies the boll wee- vil. With this cotton, the use of poison has | been found necessary only while the stalks are young. After the bolls have developed, | the yield is assured without the further use | of poison, for the thickness of the hull fur “| boll could be made so thick that it could not be penetrated by the boll weevil came to Mr. | Cochran about ten years ago when he read lof the ravages of the pest in the States to the west and realized that it was only a | matter of years when the Georgia farmers | would be faced by the weevil problem. Set- ting himself to the task of producing a thick bolled cotton, he selected three varieties with which he was familiar and planted some of the seed. Calcium arsenate was used by Mr. Cochran while his cotton was small, giving the bolls an opportunity to obtain their growth, and then discontinued. Other cot ton, however, was practically a total loss when the use of the poison was discontinued at the same time. Practically every green boll in the field was literally peppered with holes around the stem—the bolls were the |only thing in the field that remained green at the time—but when a boll was cut open it was found that, with rare exceptions, the cotton was undamaged. Most of the bolls, however, opened perfectly, even though they were perforated at the base all around the | stem. The weevil had done its best to get through to the lint inside, and failed.— Uir’s. Record, 85:7, 1 p. ill. Will Faster Flying Be Dangerous? — Yes, says Major L. H. Bauer, Commandant, the School of Aviation Medicine in Aviation (16:7, 2 pp.). In making turns, centrifugal force hurls the blood from the brain. He also changes the flier’s body from vertical to horizontal. Continues the author, “Have you ever jumped quickly out of bed and felt dizzy, everything in front of your eyes be- coming blurred? If so, your circulation, which was adjusted to the horizontal position in bed, did not adjust itself quickly enough to the upright position. As a result you | had insufficient blood in your brain causing | temporary dizziness and faintness. This will give you perhaps some idea of how a racing | pilot feels as he turns the pylons. Centrif- ugal force pulls on his body and as a result everything in his body that can move does so in the direction of the pull. This means that his blood, which is, of course, fluid, is | carried away from his head into the easily enlarged splanchnic vessels, and even into his legs. This means that he has a lack of blood in his brain or what medical men call ane- mia. When we have anemia of the brain we | become unconscious. Hence, a flier may be- May, 1924 come unconscious when making a turn at terrific speed. When a man is flying at the rate of four miles per minute, it will be seen that making a turn occupies but a moment. Anemia of the brain causes faintness and unconsciousness immediately. The flier quick- ly recovers because the circulation rapidly adjusts itself to the new position of the body and the action of the centrifugal force quickly changes to the direction of the new line of travel. Is it possible to maintain a speed so great that the anemia produced will be so marked and so prolonged that recovery will not take place? The answer is probably yes. We cannot say how great this speed will be. Experience only will show. How- ever, we have another factor, not yet men- tioned, on which we shall have to figure. Dr. Garsaux of France made some experi- ments with dogs. He rotated them on a wheel at speeds varying from four to six turns per second. Some of the dogs showed actual injury to the brain from the brain be- ing pressed against the skull. Recovery fol- lowed in some, death in others. Autopsies showed that there was an anemia of the brain, and an engorgement of the vessels of the abdominal area, thus bearing out our statements about the aviator. It is therefore not a wild theory to presume that a speed may yet be attained which when a turn is made would be sufficient to cause pressure on the stem of the brain in such a manner as to cause death. Furthermore, the force of such violent action would be sufficient to rupture blood vessels both in the brain and in other parts of the body, which in them- selves might be sufficient to cause death or lasting injury. Metallurgy The Alloy Burrowlite is made from nickelferous ore obtained in the Sudbury district of Ontario. In the smelting process the ore is crushed and then treated in a re- volving cylinder from which oxygen is ex- cluded and into which a gas containing 89 per cent hydrogen and 10 per cent nitrogen is introduced. The ore then is smelted in a crucible or other suitable furnace and seat tered on the floor. After 24 hours’ exposure to the air the product disintegrates into a | purple colored powder which is further re nishes full protection to the precious staple | | inside. The idea that the hull of the cotton | fined and cast into pig form. The smelting process requires about four days. Properties imparted to steel by the addition of the alloy include toughness, great density, a high elas tic limit and ultimate tensile strength, either high or low longation as desired. and ma chinability even when showing a brinell hardness of 360 or more.—Iron Trade Rev. Alloying Nickel with Cast Iron.—Cast iron is emancipating itself from its accepted role of poor cousin to steel, and much more eare and attention, and what is more signifi- cant, expense, is devoted to its manufacture. The effect of nickel on iron depends upon the presence and amounts of other elements, upon the form of the earbon and other fae- tors. The presence of nickel in cast iron causes increased graphitic carbon formation ; i. e., nickel tends, as does silicon, to gray the iron. This effect is quite definite but fairly mild; 1 per cent of nickel being equal per- haps roughly to from %4 to 1 per cent of silicon in this respect. The nickel does not form carbides, but dissolves in the ferrite of the iron. If the composition is such that combined carbon is present in the castings, this will be fine in structure in the presence of from. 1 to 5 per cent nickel, and more resembling sorbite than pearlite, and in con- sequence harder. Therefore, it will be seen that nickel exercises two effects quite oppo- site in nature, by lowering the combined earbon it softens the iron, but by sorbitizing the pearlite matrix of the iron, it hardens it. Which of these will prevail depends largely on the amount of combined carbon. If this is low in the composition of iron under con- sideration ; i. e., if the iron is soft and open the nickel will soften it still further. If it is high, from 0.3 to 0.8 per cent, the hard- ening effect will predominate, as in fact it generally does in practice. Grades of gray iron carrying from 0.50 to 0.85 per cent of combined carbon in general will be hardened, strengthened and toughened by the addition of from 1 to 5 per cent of nickel. Increases of from 15 to 40 per cent in hardness and in bending or compressive strength are thus obtained. The use of nickel often is bene- ficial, particularly in thin sections, in that good values of hardness may be obtained without incurring the risk of obtaining chilled or mottled iron or hard spots. The hardness obtained in gray iron by nickel additions is not due to an increase in the amount of carbide present, as it is when (Continued on page 350) re

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May, 1924 SCIENTIFIC AMERICAN LT NLA When you own a sweet-running Willys Knight you own a car you want to keep. As the days and weeks and months slip by, you are amazed and delighted to find yourself in possession of an engine that actually improves with use. Any number of Willys-Knight owners have reported 50,000 miles and more without any tinkering with the engine. No valves to grind. No carbon cleaning. Carbon only increases compression. This engine is quieter, smoother, more power- ful at 15,000 miles than when new. WILLYS-KNTG. ” a RUTH ee All these benefits are due to the very simplicity of the Willys-Knight sleeve- valve principle. For simplicity means longer life—fewer parts to need repairs. Money’s worth means mileage. And mileage means a WillysKnight. Mileage, plus absolute freedom from clicking valves and hammering cams. Freedom, plus the pride and satisfaction of owning a car you want to keep, season after season. No WillysKnight engine has ever been known to wear out. Willys-Knight Models: 2-pass. Roadster $1175; 5-pass. Touring $1195; 7-pass. Touring $1325; 5-pass. Coupe-Sedan (Standard $1450, De Luxe $1550); 5-pass. Sedan $1695 (De Luxe $1895); 7-pass. Sedan $1995; all prices f. 0. b. Toledo. We reserve the right to change prices and specifications without notice. 4 Witys-OverLAnp, Inc., Totepo, On10 ~=—@ Wtttys-OverLAND Sates Co. Ltp., Toronto, CANADA 349 You Want to Keep It! Be uf. Bao ee. © I § H ER 5

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or ov 0 rae fit CRAY ae “We Have Cut Their Costs Fifty Per Cent” A Sterling Grinding Engineer visits a plant in Michigan. He reports : We have had three very difficult grinding jobs offered to us and on each one we have been able to cut their costs. On one job we have cut them fifty per cent. The operators are working on a less rate and making easier money. Performance! There you have it. But this is not unusual. It is simply an incident in the day’s work—incidents that are abundantly rich in their assurance to you that Sterling Grinding Engineers can come into your plant and with Sterling Wheels show you new economies and better grinding. Sterling Grinding Engineers are practical men. They know grinding from the shop out. Talk to one. Invite him into your plant. Let him select the Sterling Wheel that he knows will give the best result. Let him test it. The results will show you, just as they have shown dozens of other plants, more and better grinding for this is the goal of the Sterling Grinding Engineers — a goal that is being attained sornewhere every day. The Cleveland Stone Company Cleveland New York Boston The Sterling Grinding Wheel Company Division Factory: Tiffin, Ohio Offices: Cleveland, Ohio STERLING ABRASI AND STERLING GRINDING MACHINES The 50% Thrust Capacity Here ir a unique feature of ‘‘Commercial’’ An- nular Ball Bearings. Due to the exclusive three- contact design, these bearings can sustain thrust loads of 50% of their radial load capacity. The resulting adaptability is of great importance. Unexpected thrust loads and stresses’ have no harmful effect and the same bearing may be used to carry various combinations of radial and thrust loads. Although very inexpensive, these bearings are carefully made of good material. We have just issued a truly informative booklet on “‘Commercial’’ Annular Ball Bearings, giving load capacities and the uses of the various types. We shall be pleased to send this booklet to all inquirers. The Schatz Manufacturing Co. 230 Fairview Ave., Poughkeepsie, New York Commercial ANNULAR BALL BEARINGS | study | | | all metals now known. SCIENTIFIC AMERICAN Scientific American Digest (Continued from page 348) obtained by lowering the silicon content, with consequent attendant machining dif- ficulties, but is due to the superior and finer form of the pearlite or carbide in the pres- ence of nickel.—Jron Trade Rev. 74:8, 2 pp. Permalloy has such remarkable mag- netic qualities that its use in the manufac- ture of submarine cables will permit mes- sages to be transmitted at speeds many times that now obtainable, and that is only one of the many applications that this new alloy is sure to find. Permalloy is an alloy of nickel and iron characterized by extremely high magnetic permeability at low magnet- | izing forees. Its extraordinary “magnetic permeability” means the ease with which magnetic “lines of force” penetrate it and | make of it an electro-magnet. It is far the | most easily magnetized and demagnetized of The particular com- position which is best in this regard contains about 80 per cent nickel and 20 per cent iron. The mere mixture of the two metals is, however, not sufficient to secure the high- est permeability. A special heat treatment is also required. When properly heat treated its initial permeability is more than thirty times that of soft iron. Another interesting property of nickel-iron alloys of about this composition is extreme sensitiveness of magnetic properties to mechanical strain. So far as has been determined, however, it is only in connection with its magnetic prop- erties that permalloy is unusual. The X-ray of these alloys reveals that their crystal structure is like that of nickel. Perm- alloy can easily be cast in ingots, reduced to billets, drawn into rods and wire, and rolled to thin tape. To the engineer the dis- covery of permalloy will mean the accom- plishment of results heretofore believed im- possible. For the scientist the principal in- terest in these high nickel-iron alloys may well lie in the large response of their mag- netie properties to simple external controls. Without alteration of composition these properties may be adjusted through extra- ordinary ranges by strains, by magnetization, or by heat treatment. This allows a more definite study of the way in which these} factors are related to magnetic properties | than has been possible with materials hitherto available in which their effects are comparatively small and may be associated with complicated and irreversible changes | in other properties.—Can. Min. Jour. Desulfurization of Coke by Steam, the subject of experimental work conducted by the Department of the Interior and the Car- negie Institute of Technology at the Pitts- burgh Experiment Station of the Bureau of Mines, has demonstrated that the steam- ing process effects a greater sulfur re- moval than is possible with other processes. The economic importance of the results of these experiments is that they point the way to future utilization of enormous reserves of high-sulfur coals not now suitable for | coke making. At the present time only low- sulfur coals are used for this purpose. Sul- fur in metallurgical coke gives rise to many problems and difficulties in furnace opera- tions. Over 114 per cent of sulfur is likely to produce an inferior grade of iron. Sul- fur will, in addition to causing trouble in the furnace, make it difficult, if not impos- sible, to work the iron. Any process for re- moving this deleterious substance from the coke is therefore of value to both the manu- facturer and consumer of coke, if the cost is not prohibitive. In addition to solving one of the principal problems of the steel indus- try, this removal would create a much greater coal supply from which the coke producer would draw his raw material. Many of the coals of Pennsylvania, West Virginia and Kentucky are so high in sulfur that their use for the manufacture of metallurgi- “al coke is prohibitive, without preliminary treatment by the present known means of coal cleaning, principally coal-washing, which is not always an effective remedy. Illinois has the greatest potential coal sup- ply of any State in the Union, with the pos- sible exception of Wyoming, which is under- lain by immense fields of low-grade sub- bituminous coal. Nearly all of this Illinois coal will make good coke, if not alone, when used in proper mixtures with other coals; but in most cases the sulfur content is! above the limit fixed by present standards. Many processes have been tried for the re- | moval of sulfur from coke, including steam ; but most of them have not met with any degree of success. The investigators at the | Bureau of Mines laboratories found that a tween 10 and 15 per cent of the total sulfur May, 1924 in the coke is removed by simple steaming at 750 degrees C. With alternate vacuum and pressure treatment the desulfurization is increased to 20 to 25 per cent. New Practice in Metallography.—Two important developments in metallographic analysis have been announced in recent months. One is conical or indirect illumi- nation of the specimen under examination and the other is the effeet of very high power magnification. Conical illumination, what- ever its merits, is a unique development. The results are a truly beautiful picture of the structure of the steel. The chief advantage is ability to bring out depressions and ele- vations in the erystal formation which are entirely indistinguishable by direct illuminat- ing methods. More details as to the forma- tion and orientation of erystals, their slip and deformation, and more light on grain boundaries and the effects of certain heat treatment processes are among the likely re- sults. As to high power, methods of polish- ing and etching have been so perfected that, with the aid of certain apparatus and photo- graphic equipment, magnifications up to 9000 diameters have been obtained. These have revealed beautiful cerystallizations which throw new light on problems in metal struc- ture and the effect of various hot and cold- working processes.—IJron Age, 113 :6. Steel Made Direct from Ore.—A French patent was issued recently to L. P. Basset of Paris on his method for making steel directly from iron ore. The process consists in subjecting the ore, mixed with the amount of carbon necessary for its re- duction and with appropriate fluxes, to the action of a flame obtained by the combustion of powdered coal in the quantity of heated air necessary to insure combustion to carbon monoxide and a small amount of carbon dioxide, in such a way that in spite of the slight loss of metal due to the oxidizing action of the carbon dioxide (95 instead of 100 per cent reduction) there results an economy due to the diminution in the quan- tity of powdered coal involved and the easier crushing of the latter. On the other hand, the production of carbonic acid, which is accompanied by the liberation of 14,550 B.t.u. per pound, as compared with 4450 per pound for earbon monoxide, represents an important saving on fuel.—Automotive Ind. Mining The Greatest Progress in the tech- nique of the cyanide process was made in the application of the well-known reaction by which copper and silver may be precipitated from cyanide solutions by acidification. The , hydrocyanic acid thus set free may be changed back into the form of one of its alkaline salts, by the addition of an alkali, or, with a greater degree of safety, may be withdrawn by the application of a vacuum and re-dissolved in an alkaline solution. An application of the first method is described thus by Harley B. Wright: Neutral cyanide solutions deprived of free cyanide were treated with sulfuric acid. The precipitate, cuprous cyanide, was allowed to settle and was filtered, after which the solution was made alkaline again by lime and was re- turned to the circuit. Incidentally, 80 per cent of the gold was precipitated with the copper.—LEng. and Min. Jour.-Press, 117 :3. Electric Wire Safety Lamps.—Flame safety lamps have been available for over a hundred years, but during the last ten years safe and practical electric lamps have been perfected. These have eliminated many of the flame safety lamps, and in a few mines have replaced open flame lamps. But there are still more than twice as many open lamps as electric lamps in the mines of the United States, all of which the Bureau of Mines declares should be discarded in favor of an approved type of electric lamp. There are several electric miners’ lamps which have been approved by the Bureau for safety and efficiency, which give good light, and which are easily maintained and earried. Some flame safety lamps will always be used, but mostly for detecting gas; although they might be supplanted if some simple, reliable, and cheap gas detector were developed. An open light and gas constitute a vicious haz- ard; while if there be coal dust present in the vicinity the consequences are multiplied many times. An open light and black blasting powder also constitute an explosion hazard, vividly attested by several serious disasters. Gas is released from the coal formation in numerous ways—by small feeders or blowers in the coal; by falls of roof; by drilling into or blasting vaults, horsebacks, and clay veins; from the floor— (Continued on page 352)

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May, 1924 SCIENTIFIC AMERICAN The new Ford all-steel body and weather-proof cab mounted on the Ford worm drive chassis at $490 f. o. b. Detroit, is the world’s lowest priced complete one-ton truck. A Preference Based on Quality There is deep significance in the fact that 78° of all trucks of one ton or less capacity in the United States are Fords. This overwhelming preference for Ford haul- age units has its basis in the low cost of Ford transportation, the rugged construction of the truck itself, and its unusual adaptability to every line of industry. Mechanical excellence, simplicity of design and ample power are further factors that have contributed to the popularity of the Ford One- Ton Worm Drive Truck. As a logical step in providing dependable transportation at the lowest possible cost, the Ford Motor Company is now producing an all-steel body and steel weather-proof cab mounted on the Ford Truck Chassis, selling at the remarkably low price of $490. Merchants standardizing their delivery sys- tems on Ford One-Ton Trucks have available the facilities and assistance of over 33,000 Authorized Ford Service Stations, conven- iently located to their business. C= Detroit, Michigan See the Nearest Authorized Ford Dealer FORA CARS -TRUCKS -TRACTORS 351

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352 SCIENTIFIC AMERICAN Transportation Ability Determines Value The high value which users place upon GMC trucks is based, not upon their initial cost—but upon their ability to deliver dependable, economical and endur- ing haulage. And this value is further guaranteed by the knowl- edge that the list price of a GMC truck is the actual cost of producing it, plus a fair profit—no more. Likewise. GMC users have come to value their “used trucks” in the same way—by the actual transporta- tion left in them. Consequently, resales to GMC users become transac- tions governed strictly by the actual merits of the new GMC, and of the old truck that is to be “traded.” Only upon such basis can sound, satisfying business for both buyer and seller be established. GENERAL MOTORS TRUCK COMPANY Division of General Motors Corporation PONTIAC, MICHIGAN Distribution Centers at Akron *Denver *Minneapolis Rochester *Atlanta Detroit *Milwaukee *St. Louis Baltimore Dayton Montreal, Quebec *San Francisco nenem - aso ane = *Seattle rookiyn rie ew Yor *Spokane Boston Houston Oshawa, Ont. Salt Lake City —_ ayy ya soinew : aumont ansas City maha san Antonio *Chicago *Los Angeles *Philadelphia Shreveport MF mee ane “[puloviiie ae ew h orem to, Cue. c eveian incolin ‘ortian ancouver, - Cincinnati London, Eng. Parkersburg Washington Clarksburg “Memphis *Pontiac Winnipeg, Man. *Dalias *Direct Factory Branches May, 1924 (Continued from page 350) and in some places may even leak into the workings from a gas well. Nobody can say that gas will not be encountered, but it can be said that it may be sooner or later. Therefore, as a definite safety measure, the | Bureau of Mines holds that the possibility | of a gas release is ever present in coal mines, and that closed lights should be used. In other words, the open light is unsafe. Scientific American Digest | Classified Advertisements The Market Place for the Small Advertiser Rate for advertising in this rection 15 cents per word, for each insertion, payable in advance. Minimum space acceptable, 20 words. Rate card giving discounts for number of insertions sent on request. Ad- vertisements for insertion in - Foch issue should be in our office by May 20. Tungsten Steel for Drills—The Mining Journal (London) records an attempt on the Rand to use an extra hard steel of high tungsten content for drilling rock. A method has been found of welding the alloy to ordi- nary drill steel. The best ordinary drill steel does not drill more than 15 to. 18 ins. before it is blunted and loses its gauge, and has to be resharpened. The special | tungsten steel alloy costs 2s. 9d. per Ib.,| against 614d. to 7d. per Ib. for ordinary | ae FOR ADVERTISERS I WRITE BOOKLETS, folders, letters, equelete jew-ap for manutacturers, mail-order dealers. “ong experience. Write for prices. L. Taylor, Box B 44, Freeport, Ti. ADVERTISE in 24 Big Sunday Newspapers, 24 words, $15. Helpful Guide listing 1000 publica- tions, 4c stamps. Wade Advertising, Baitimore Bidg., Chicago. steel; but it is claimed it will drill 48 ins. | before needing re-sharpening. It is proposed to weld a short length of the high cost alloy | to the ordinary steel. This has been made} possible by the introduction of the electric butt-welding machine. With this machine | the two surfaces to be welded are brought | together in such a way as to complete an | electric circuit, and in the intense heat gen- | - | erated at the junction of the two steels the | | requisite pressure is applied, and the weld | | is complete. With this machine nearly a} weld per minute can be made, and if these | welds will stand up under the repeated per- | cussion of the hammer-drill blows in the drill- | hole, there is a possibility of a big advance | in technical practice. In recent years the | | annual consumption of rock-drill has aver-| | aged 250,000, and, even if we deduct the | cost of installing electric welding furnaces, | | the gain of having to handle half the weight | | of drill steel formerly used, both on the sur- | face and underground, and the reduction of | sharpening charges, will be considerable.— Can. Min. Jour. | | Rubber Linings for Tube Mills.—The | - tube mill is used for breaking up ore. Ordi- | | narily they consist of a large tube of metal | | lined with alloy steel in order that the abra- | sion of a ton of loose moving and falling ore | may cause the least possible amount of wear. | | Strangely enough it has been discovered that | | rubber forms a better lining for tube mills} | than steel. It lasts longer than steel. Says | Canadian Mining Jour., Metallurgists in | | South Africa have not been slow to take up| the new idea. The original experiments at Cobalt, Ontario, stimulated immediate action. In Rand practice lumps of the hard, abrasive ore are used in the mills in place of the| steel balls or rounded pebbles used in Cana- | dian mills. These lumps are, of course, angu- | lar with sharp edges and are extremely | tough. The first step was to place blocks | of rubber between the steel liners. From | | this it was determined that vuleanized rub-| _ | ber does not wear as well as soft, raw rub- | | ber. Experiments with the latter are still | proceeding and, though it is too early to | conelude definitely that the soft rubber will | replace steel economically, it is admitted | that so far as the experiments have gone | | they are distinctly encouraging. First cost | | of the mill is very much higher when lined | with rubber, but against this added cost is| | the longer life of the rubber, estimated as at | least three times that of steel, and other ad- | vantages such as increased grinding capacity and lower power consumption. In Canadian | practice a saving in power of 24 per cent | has been recorded, the rubber lining being | only about one-eighth the weight of one of steel. A New Prospecting Method.—A novel | development campaign by which extensive | prospecting is being done with rock drills and sectional drill steel from drifts, cross- | cuts, raises and stopes has been inaugurated | | by a Utah mining company. The new method |is proving highly satisfactory as to costs| | and time required to obtain a given amount | of information. As the silver-lead ores of this mine occur in rather irregular bodies | — | found in three favorable limestone forma- | tions, prospecting and development are of first importance. That marked economies | can be made and much ore located by the new method has been proved and its use is | being expanded rapidly. The progress made in developing the equipment used is interest- ing.’ In 1916, a 45-ft. horizontal hole was driven from the top of a raise to connect with and drain the East shaft of a Butte mine. The raise being rather small, 2-ft. sections of rod made from 114-in. pipe were used, one piece being welded to a regular drill shank, the remaining sections having AGENTS WANTED MAKE MONEY silvering mirrors, all kinds plating, knives, spoons, auto headiights. Outfits furnished. International Laboratories, 309 Fifth Ave., Dept. RA, » New York. NEW AUTO ACCESSORY. Costs 6 cents. Re- tails $1.50. “‘Free Sample.”’ Box 494-R, Hart- ford, Connecticut. $60-$200 A WEEK. Genuine Gold Letters for store windows. Easily applied. Free Samples. | Liberal offer to general agents. Metallic Letter Co., 440A, North Clark, Chicago. BIG MONEY and fast sales; every owner buys | gold initials for his auto, You charge $1.50, make $1.44; 10 orders daily easy. Samples an | information free. World onogram Co., Dept. | 31, Newark, J. _TELL_ THE WORLD WITH SIGNS. Our gen- uine gold window sign letters are an excellent money-making proposition for handy men. Slann Sign System, Bethune Ave., Detroit, Mich A BUSINESS OF YOUR OWN. Make Spark- ling Glass Name and Number Plates, Medallions, Checkerboards, Signs. E. Palmer, 519 Wooster, O. ~ AMERICAN ‘MADE METAL TOYS AND NOVELTIES MANUFACTURERS on large scale and home- workers wanted to manufacture patel ay and novelties. Barking Dogs, Wag Tail Wild Animals, Automobiles, Indians, Bird Whistles, Cowboys, Baseball Players, Cannon, Toy Soldiers, Statues of Liberty iniature Capitols, Bathing Girl Souvenirs and others. Unlimited possibilities. Guaranteed casting forms, complete outfit, fur- nished manufacturers from $5.00 up. No experi- ence or tools necessary. ousands made complete per hour. 1924 business starts now. We buy | goods all year and pay high prices for finished goods. Cash on delivery. Contract orders placed with manufacturers. Special casting forms made to order. Catalog and information free. Corre- spondence invited only if you mean business. Metal Cast Products Co., 1696 Boston Road, New York. AUTOMOBILES AU TOMOBILE owners, garagemen, mechanics, send for free copy America’s popular motor maga- zine. Contains helpful, money-saving articles on repairing, overhauling, ignition, carburetors, bat- teries, etc. Automobile Digest, 542 Butler Bldg... Cincinnati. : ‘BUSINESS S OPPORTUNITY ITAL Y. A first rate Italian Firm which has re- cently erected a very fine and large store-house in the best point in Rome, wishes to enter into busi- ness connection with an important American Com- pany willing to throw its products on the Itaiian market. Best references can be furnished. Ad- dress: Esposizione Salvadori. Rome, Itaiy. YOU CAN have a business profession of your own and earn big income in service fees. A new system of foot correction ; readily learned by any- one at home in a few weeks. Easy terms for train- ing; openings everywhere, with all the trade you | can attend to. No capital required or goods to buy; no agency or soliciting. Address Stephenson Laboratory, 23 Back Bay, Boston, Mass. CHEMISTRY YOUR CHEMICAL problem solved and working process furnished for FIVE DOLLARS. _ Write me. W. Stedman Richards, Consuiting Chemist, Box 2402, Boston, Mass. FOR SALE ASSORTED SIZES D. C. MOTORS \% HP. to 10 HP. These were used by us in our old plant which was in the D. C, district. We guarantee them to be mechanically in good condition. Wilt sell singly or —_ lot. rite for prices, ete. Address Rietz, Electric Ventilating Company, 2850 N. a Avenue, Chicago, Illinois. a. IMPROVED MADE TOYS WANTED Manufacturers and Houseworkers to aniiine Metal Toys and Novelties. Wonder- ful opportunity. Millions n In Whistling Birds, Wild Animals, Wag Tail Pups, Crowing Roosters, Automobiles, Baseball Players, Statue of Liberty, Indians, Toy Soldiers, Barking Dogs; and 50 others. No experience or tools necessary. Guaranteed casting forms with complete outfit, at cost. From $3.50 up. We buy goods ail yous. Cash on delivery. Higher price for finished goods. Contract orders placed. Send for catalog and in- formation free. The Improved Metal Casting Co., $42 East 145th St., New York. ae INSTRUCTION _ USED correspondence school courses, only one- quarter original price. Free bargain list, 1,000 courses. lt bought. Students Exchange, Dept. 9, 47 West 42nd St., New York. Jap tion gra dic, ia ev TH. ures « dress tonia, PH derful compl son, C ’ of 600 MAI what ft ing se big in rado n wantec the co county SEL main | pay in ment. change

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May, 1924 Classified | Advertisements — Continued ‘FOR INVENTORS WE DEVELOP your invention to practical use; make necessary drawings, models ; expert engineer- ing counsel; before or after Patent ; also help market your invention. Investigate. (No attor- neys or brokers.) Caston-Guay Engineers, Wash- ington, Cc. IF YOU HAVE A PRACTICAL, useful inven- tion to sell, write us promptly, stating whether patented. American Patents Corporation, Barris- ter Building, Washington, D. C. WE DEVELOP your shape for resentation drawings, ideas into commercial to — making wor ing moc els, rime nts or tests. Courtesy, efficiency, secrecy on ample equipment ; 30 years’ experience. Ducorron- Rich Engineering Co., 504 Pacific Mutual Bidg., Los Angeles, Calif. TO SELL YOUR PATENT, write me; enced handling, immediate action. Address Arthur S. Billings, Suite 401, Dekum Bidg., Portland, Ore. I SELL PATENTS. Established in 1900. To buy or sell write Charles A. Scott, 773SA Garson Avenue, Rochester, N. Y. SPECIAL IZED SERVICE FOR INVENTORS. You furnish the idea, we'll work it out. Expert machine designing. Draftin Opinions given on racticability of ideas. Confidential our ideas fully protected. Write for full par- ticulars. Otis Engineering Co., Desk G H, Omaha, } Nebraska. LANGUAGE: ES WORLD- ROMIC SYSTEM, Sediehen to All| Languages. Primers, $1.94 each language; Bo- hemian, Bulgarian, Cantonese, Danish, Dutch, English, French, German, Hungarian,’ Italian, Japanese, Latin, Panjabi, Polish, -ortuguese, Ru- manian, Russian, Spanisir, Swedish. Pronouncia- tion- Tables, 30c each language. Dictionaries, grammars, 4,000 languages; Afrosemitic, Amerin- dic, Eurindic, Indopacific, Siberic, Sinindie. Lan- ages Publishing Company, 8 West 40th Street, ew York. LITERARY ASSISTANCE SPEAKERS, Lecturers, Writers—We prepare | speeches, lectures, essays, special articles. rompt, scholarly service. Authors Research Bureau, 500 Fifth Ave., New York. MAIL ORDER BUSINESS $50 WEEK, evenings, I made it; mail order business. Booklet for stamp tells how. Sample and plan, 25 cents. articles worth $3. ‘ree 12 Alscift Seott, Cohoes, N. Y MANUFACTURERS UNUSUAL OPPORTUNITY FOR DIES, Stamp- ing, Die-casting, plating, enameling, screw-ma- chine and wire products. Reasonable. Large ex- cellent equipped factory. Metal-Craft Manufactur- ing Co., Box 259S, Chicago. MISCELLANEOUS ENGINEERS AND DESIGNERS, small anti-fric- tion ball bearing, for weight and thrust; accur- ately made, carefully hardened. Wholesale rates for small quantities. Oliver C. Knipe, Mech. Engineer, 526 Columbia Road, N. W., Washington, D. C. ENCYCL OPAEDIA BRITANNICA, India paper. 50. New International 2nd Edition, $75. ton iggs, Crilly Bldg., Chicago. SELL TUFGLAS BATTERY TRAYS, for use under Radio Batteries; saves Carpets and Rugs. Ideal for use in Refrigerators, many other house- hold uses. Write Russell B. Cressman, Dept. A, 200 Fifth Ave., New York City. ‘GENU INE Sedan made bashete, on earth, and wampum. logue mailed free. Francis Giiham, California. Kelseyville, PHOTOGRAPHERS — THAT | SETTL ES IT. Get your outdoor expos- ures correct by using my Scale. Send your ad- dress for full information. Elmer Harrold, Lee- tonia, Ohio. PHOTOG RAPHS without films or plates. Won- derfully artistic. Nothing to sell. Photo and complete instructions thirty cents. Will Wilkin- son, Clarkson, New York. POSTAGE STAMPS 4 VARIFTIES Cuban stamps, 10 cents. List of 6000 low-priced stamps free. Chambers Stamp Co., 111-S Nassau St., New York City, N. Y SALESMEN MAKE $100 WEEKLY IN SPARE TIME. Sell what the public wants—long distance radio receiv- ing sets. Two sales weekly pays $100 profit. No big investment, no canvassing. Sharpe of lo- rado made $955 in_one month. Representatives The Ozarka plan is sweeping giving name of your ones. write today, wanted at the country county. Ozarka, 824 Washington Blvd., Chicago. SELL COAL IN CARLOAD LOTS. Side or main line. Experience unnecessary. Earn week's pay in an hour. Liberal drawing Account arrange- ment. Washington Coal Company, 759 Coal Ex- change Bidg., pomnneat WANTED A PRODUCT or an idea suitable for manu- facturing in a fair size machine Ti by a repu- table concern in busines since 1882. The New one Wire Stitching Mach. Co., Camden, N. J. “WAR RELICS AND WAR PHOTOS FOR DENS. Collected from Europe’s Battle- fields. Firearms, medals, helmets, etc. Illustrated catalogue and Sample War tos, 25c. Lieut. Walch, 2117 Regent Pl., Brooklyn, N blankets, best | Wholesale priced cata- | experi- | dealings. | | | dieation of Germany’s titanic efforts to gain | world mastery in commercial life. SCIENTIFIC AMERICAN pipe threads on both ends. The necessary | sleeves were provided for coupling the rods | together as in ordinary pipe fitting, with the exception that the threads were cut to permit the pipe meeting end to end. Bit ends were threaded to fit the sleeves. The hole was drilled in altered Butte granite and the shaft drained. The Anaconda Copper Mining Co. developed the method still further and drilled holes to a depth of 90 ft. through altered | granite and gob. During the latter part of | 1923, the campaign of deep hole prospecting referred to was entered upon and carried out. As already stated, the results of this cam- paign have been satisfactory and the use of the method is being rapidly expanded. Nor- mally, 12 miles of development work is done annually in the Chief Consolidated mine, and, as this consists largely of cross-cuts, much of this work can be done by drill holes at a pronounced saving. The present equip- ment conforms closely to that used in stand- ard mine practice and consists of a rock drill, 3-in. single screw columns, arms and saddle, 1-in. air hose, *4-in. water hose, drill bits, threaded drill rods, sleeves and water- connection swivel. —Eng. and Min. Jour. Press, 117 :9, 2 pp., ill. elieees Locomotives with Flexible Wheelbase on the Garratt system are being introduced to a considerable extent in Africa and India for narrow-gage lines having heavy grades and numerous sharp curves. The largest of these engines is a 97-ton locomotive of the 2-8-0-0-8-2 class, built in England recently for the meter-gage lines of the Burma Rail- way and it is the first engine of its type to have eight-coupled groups of wheels. In other types of flexible locomotives the main frame extends the full length of the loco- motives and is supported on one fixed and one swiveling group of wheels, as in the Mallet engine, or on two swiveling groups, as in the Fairlie engine. The Garratt en- gine, however, has the boiler carried on a steel deck slung between two trucks, with pivot supports on the near ends of the trucks and the cylinders placed at the outer ends. Additional adhesion weight is given by tanks and coal bunkers on the tracks. In the en- gine for the Burma Railway the truck bear- ings are spaced 32 ft. 9 in. center to center and the total length is about 70 ft. The two end driving axles and the two groups of eight 39-in. driving wheels can adjust themselves independently on curves and the engine is designed to traverse curves of 250 ft. radius. On one truck is a 1500-gal. tank and on the other is a 600-gal. tank and a 5-ton coal bunker. The weight averages 10 tons on each driving axle and 914 tons on each of the two end axles.—Hng. News Record. Americanizing German Railway Equip- Bulk freight traffic is an impor- tant source of revenue on any railroad, and decidedly so in Germany. One of the new objectives of the railway administration is to develop the methods of handling this class of traffic to the highest efficiency, and in line with this policy, they have gone so far as to contenplate the practical re-organiza- tion of the system of handling the commodi- ties. They are following in this respect, certain principles which were established long ago in American railway practice. Due to a combination of conditions, the German railways are putting into service experi- mentally certain new types of freight car equipment which are a decided advance both as to size ana weight and as to improved design, over anything which has been in use heretefore. The types are of 50 tons eapacity, one for bulk freight service, and the other a flat bottom ear for general ser- vice. With the introduction of the new rolling equipment, the railroads are also ad vancing the standards as to track and road- bed. A heavier rail, weighing 49.3 kg. per meter and designed to withstand a wheel pressure of 12.5 tons is being laid on the trunk lines. Bridges are being reinforced or rebuilt for 25 tons axle load, and eight ton-meter longitudinal load, so that a few years hence, these heavier standards will prevail on all the main lines. In handling bulk commodities, the feature of automatic | unloading presents such obvious economies that its importance can scarcely be over- estimated. This idea of rapid unloading is applied in the new designs of cars to the handling of commodities such as coal, coke, sand, gravel, ete. This improvement in Ger- man railroad equipment is just another in- It is the counterpart of the expansion of German in- dustries since the war.—Railway Rev., 74:6, 2 pp., ill. 353 FACTS ABOUT A FAMOUS FAMILY The steel which Gen- eral Motors uses in a year would construct 8 Leviathans, in- cluding their machin- ery. It would build 2000 locomotives, or lay arailroad track from New York to Denver. 375,000 tons of steel Many people suppose that all steels > alike. But General Motors met- allurgists specify 45 different analy- ses of steel for uses as varied as the sturdy frame of a five-ton truck and the delicate needle-valve of a car- buretor. Altogether, the companies which are members of the General Motors family use more than 375,000 tons of steel a year, equal, approximate- ly, to 8,300 freight car loads. So large a purchase insures both quality and economy, and makes General Motors an important factor in the lives of many thousand families who depend upon the prosperity of the stee] and allied industries. GENERAL MOTORS Buick - CHEVROLET * OAKLAND GMC Trucks CADILLAC * OLDSMOBILE * General Motors cars, trucks and Delco-Light products may be purchased on the GMAC Payment Plan. Insurance service is furnished by General Exchange Corporation.

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354 SCIENTIFIC AMERICAN “It’s HARD yet it’s Easy.’ HARD MAPLE is easy to get, easy to pay for,and hard to equal. For 156 dis- tinct spec- ialized uses it is the Standard Wood in Ameri- can I[n- dustry. The 156 kinds of use where HARD MAPLE is a “must” (if quality is an object) are listed and explained in the 60 pages of the new HARD MAPLE Book. Also there are 10 tables of official statistics, showing the comparative strength of all American hardwoods, as to com- pression, shearing, tension, etc., also beam-tests, impact-bending, etc. The book is a revelation of the HARD MAPLE FACTS of today in the American manufacturing world, and is a thought-stimulator as well as an invaluable quick refer- ence work, Kindly use letterhead in writing for your copy. The Northern Hard Maple Manufacturers 311 F.R.A. Building, Oshkosh, Wisconsin, or 311 Cummer-Diggins Building, Cadillac, Michigan “This is Station x“ (Continued from page 338) short-wave transmission coming in to fill the role of the ideal link between “pick-up” microphone and broadcasting station. A short-wave transmitter, located at the very seene of the radio feature, can now be employed to pick up the sounds and trans- mit them through space at an inaudible fre- quency, so far as receiving sets are con- cerned, to the nearest broadcasting station where the feature is received, amplified, and re-broadeasted on standard wave lengths for the radio audience; and, furthermore, if this station is a primary broadcasting station, the feature is put on the air at an inaudible or repeating frequency which will have high power to obtain distant transmission. This latter wave will be picked up by a chain of repeating stations of the same nature as the Nebraska repeating station of today. There are a good many possible paths in the ether for these repeating waves, so we| are assured by radio engineers; and with | a sufficient number of properly located high- | power repeating stations an indefinite num- | ber of programs will be made available wood, the secondary broadcasting stations of low | power, which will repeat and broadcast at | a frequency or wave length audible with the | usual receiving sets. The Question of Dollars and Cents Aside from the solution of several of our present technical troubles the short-wave repeating scheme tends to solve the economic phase of broadcasting. Long has it been predicted that at some future time many | of the independent broadeasters are bound | to give up broadcasting, in that there are | no tangible returns for their efforts and the expenses of broadcasting are steadily mount: } ing higher and higher. Then, too, it seems} but a matter of time when our radio enter-} tainers, who now give their services so} willingly for whatever publicity there may be in broadcasting their efforts, will demand remuneration for their services. Please note how this economic phase is met by the short-wave transmission from the primary broadcasting station and the repeating stations scattered throughout the country. The primary station, located in the metropolis, is in a position to get the finest talent of the land. If the artists must be paid, then the expenses can be distributed among all the repeating stations over a wide expanse of the country. Even at the present time the American Telephone & Telegraph Company has such a plan in actual oper- | ation. Instead of short-wave transmission, this company, with its splendid network of | telephone wires, makes use of telephone links to tie up the master studio with the re-broad- | easting stations. In Washington the tele- phone company maintains a_ special re- broadeasting station, WCAP, which handles the same programs as the WEAF station in New York City. Then, too, the WEAF programs are sent by wire to certain stations in New England, which re-broadeast to their local audiences. Whatever expense may be connected with the securing of the programs can certainly be apportioned among the va- rious broadcasting stations in such an ar- rangement, thereby tending to solve the great economic question of broadcasting. And at the Receiving End While the broadeasters are working on | the problem of moving the programs up| nearer to the listeners-in, radio engineers are at work on better and still better receiv- ing sets. For, let us admit, many of us like radio “fishing” best of all—this business of seeing how many stations we can pick up in one evening, and how far. The author} cannot help but indulge in a little reminis- | ecencing at this point. His thoughts go | back to those winter days in 1909, when he | was working a crude two-slide tuning coil and a erystal detector while trying to pick up the dot-and-dash message from Fort Wood which was to tell us how we were coming through with our radio telephone transmis- sion. The author fussed and fussed, but | without success. Everything but the desired | station could be heard in the head-phones; | indeed, even a passing battleship had just | called us up, with the short but sweet mes- | sage “For Pete’s sake change the tune!” | The operator aboard the battleship was re- ferring to our Anvil Chorus, which had just | been played for the fifty-first time. At any | rate, we finally resorted to the Postal Tele- | graph wires in the nearby ship-reporting | tower then in use at Sandy Hook, as a quick and reliable means of hearing from our collaborators but eighteen miles away. Fifteen years later the author sits before May, 1924 a neat cabinet with two simple dials on which are marked the call letters of various stations, both local and long-distance. The author glances at his watch; it is two o'clock. Then he looks through the radio program columns of the newspaper—it makes no difference what newspaper, for all newspapers must carry the broadcast pro- grams of the day. There is a program in Philadelphia at two o'clock. There is another program in Providence. Still another is on the air from Cleveland. One New York station is working at this hour. Very well. The two handles are turned until the dial pointer indicates the New York station. Instantly a violin solo comes out of the flared horn of the loud-speaker, standing alongside the long eabinet. The two handles are adjusted for the Philadelphia station, and out comes the voice of a well-intentioned lady speaking on some subject or other which has little appeal to masculine tastes. Once more the handles are adjusted until the indicators point to the Providence station. Instantly, the strains of an orchestra come drifting out of the horn with plenty of volume to fill the room, yet soft and sweet and most life- like. We linger a while, because this fea- ture suits our particular tastes. What a boon, this business of being able to choke off undesirable programs and to select desirable ones! Finally, we set the dials again, this time for Cleveland, only to hear a fair pianist at work. That evening we are going to visit friends |—friends who have no radio—odd people, these, but perhaps they are not to blame, for their sole conception of radio is the squawking loud-speaker in front of some cut-throat radio shop. We take the radio receiver with us, together with the loud- speaker. That evening our radio receiver is placed on the living-room table in the home of our friends. We turn the knobs and bring in the President’s speech from the banquet table several hundred miles away. We dance to the music of a Chicago orches tra. We tune in twenty-nine separate sta- tions in two hours’ time. And we sell the idea of radio to our friends before the eve- ning is over. The Rolls-Royce of Radio The set in question is entirely self-con- | tained. There is no antenna connection. No ground wire is necessary. Inside the set is a small oblong frame with a dozen turns or so of wire, known as the loop, which serves to intereept the radio waves. That little loop takes the place of the ele vated wire measuring 100 feet or more in length, heretofore required for radio recep- tion. Furthermore, this set contains a few dry cells to operate the six vacuum tubes. The only external connection is that running to the loud-speaker. And even when the set is being carried about, in the automobile, street car, canoe—anywhere, the radio waves from stations several hundred miles away can be intercepted and reproduced good and loud. Of course this particular type of set is, admittedly, the 1924 model Rolls-Royce of receiving sets. It is known as the Arm- strong super-heterodyne, having been devel oped back in the World War days by Major Armstrong—that same young man who was working on the crude vacuum tube circuits during his college days in 1913. The super- heterodyne takes the weak energy inter- cepted by the small loop, plays it off against a locally generated wave, and the resultant wave is passed through radio frequency amplifiers at high wave lengths, because the so-called untuned radio-frequency amplifica- tion is most efficient at high wave lengths, and onto the detector. This arrangement makes for the utmost efficiency with simplicity. ‘The advent of special-filament vacuum tubes with a consumption of one-quarter am- pere in some cases, and even as low as six | hundredths of an ampere in others, has made it possible to multiply the number of tubes in individual receivers. Consequently, radio engineers have been able to develop new receivers in which four, five and six tubes are employed. Whereas the receiving sets first employed in radio broadcasting work intercepted the radio energy and brought it directly to the detector tube, which in turn delivered an audio-frequency energy to one or two audio-frequency ampli- fying tubes to be amplified for very loud headphone or even loud-speaker reception, the present day receivers intercept the same amount of radio energy but pass it through | One or two stages of what is known as radio- frequency amplification, before turning it over to the detector. The consequence is (Continued on page 358) M.

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uy Ve — May, 1924 Lead makes it safe to telephone even when the lightnings play LAIN gray lead seems a stupid, lumpish metal. Yet when thunder crashes and lightning flashes around your house, that same lead enables you to use your telephone without danger of electrocution. Even if a bolt of light- ning strikes the wires while you are talk- ing, lead protects you from harm. Lead is the principal part of the fuse which is used in the modern telephone system as a protection against unusually heavy electric currents. When a light- ning bolt reaches the fuse, it melts the lead of the fuse. This stops the current and prevents it from reaching your in- strument. There are about 76,000,000 fuses in telephone systems in the country, and lead is in them all. More than 27,000 pounds of lead are used every year in renewing burned-out fuses. A secondary protection Every telephone line has, in addition toa fuse, a device called a protector. Small particles of lead in these protectors, which are both in the exchange and your end of the telephone line, melt when lightning strikes the line and break the line over which the current is traveling toward you. The amount of lead used in this way is about 1,000,000 pounds. Renewals require the use of about 700,000 pounds more every year. How lead helps you phone Lead in fuses is only one of many uses to which this metal is put in the tele- phone system. Every time you telephone you summon the help of lead. In the telephone instrument and box is an average of 51 soldered connections. Lead is in all of them. Exchanges in the United States and telephone lines run- ning out of them have billions of soldered connections, with about 322,000,000 pounds of lead in them. Changes in con- SCIENTIFIC AMERICAN nections require the use of about 70,000,000 more pounds of lead every year. Sheaths of lead Millions of pounds of lead are necessary to provide snug coverings for telephone cables. One company uses in a year more than 53,000,000 pounds, to cover 35,300,000 feet of cable. Today there are in this country about 82,000 miles of telephone, telegraph, radio and elec- £ tric light cable covered with lead — 327,300,000 pounds of it. Along this ‘able are more than 6,000,000 pounds of lead for connecting and sealing the ends of cable to keep out moisture, and for terminal boxes. Where you see lead most N telephone systems, you do not see it or realize the important work lead is doing. But in paint, lead in the form of white-lead, the basic lead carbonate, and red-lead, a lead oxide, is known the world over. And after all, it is this use of lead that is most universal. For generations painters have used white-lead on such surfaces as wood, and red-lead on metal as standard protection NATIONAL New York, 111 Broadway; Boston, 131 State St.; Buffalo, 116 Oak St.; Chicago, 900 West 18th St.; Cincinnati, 659 Freeman Ave.; Cleveland, 820 West Superior Ave.; St. Louis, 722 Chestnut St.; San Francisco, 485 California St.; Pittsburgh, National Lead & Oil Co. of Pa., 316 Fourth Ave.; Philadelphia, John T. Lewis & Bros. Co., 437 Chestnut St. against the assaults of the weather. Rot cannot destroy the house whose surfaces are covered with pure white-lead and pure linseed oil. Rust cannot attack the iron and steel that are thoroughly pro- tected with red-lead. Property owners who jealously protect their money invest- =; ments know from “ag pation | experience that white-lead gives the surest protection for the surfaces of their houses. These owners have learned the truth of the words, “Save the surface and you save all.” They realize now that the cost of good paint is secondary to protection of the covered surface. Producers of lead products Dutch Boy white-lead is the name of the pure white-lead made and sold by National Lead Company. On every keg of Dutch Boy white-lead is reproduced the picture of the Dutch Boy Painter shown below. This trade-mark guaran- tees a product of the highest quality. Dutch Boy products also include red- lead, linseed oil, flatting oil, babbitt metals, and solder. National Lead Company also makes lead products for practically every pur- pose to which lead can be put in art, indus- try and daily life. If you wantinformation regarding any particular use of lead, write to us. If you wish to read further about this wonder metal, we can tell you of a num- ber of interesting books on the subject. The latest and probably the most complete story of lead and its many uses is “Lead, the Precious Metal,” published by the Century Company, New York. If you are unable to get it at your bookstore, write us or the publishers. LEAD COMPANY

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SCIENTIFIC 356

| e | The Standard Tube for all makes of adio Receiving Sets [! is the Vacuum Tube that has made possible the broad and far-reaching application of radio teleph- ony, and that ys the most important part in the operation of your receiving set. i Radio messages from government leaders—from the ]

heads of the world’s greatest educational institutions or from those who stand foremost in the arts the world will serve to bring the human race into closer contact. Cunningham Vacuum Tubes, standard for all makes of i receiving sets— built by one of the world's largest manu- | | | |

facture:s with unlimited resources — are the product of years of manufacturing experience and the creative genius of the engineers of that great scientific organization, t Research Laboratory of the General

ic Company. es tw 1 WEE ond.. S rh OO Keng “A titi “iiilisal — . if NTH! ai BN ma — -_ The care and operation of each model of Re ae _ PATENT NOTICE Tube is fully explainec / in our new 40-page * Radto Prices on lube Data Book opies may be obtained by Uses ae ay Cansingham tubes are sending ten cents to =. San Francisco office. C-301A—65 Volts 1-4 covered by patenta ow filament $5.00 dated 2-18-02 and >-299—8 Volts .06 amp others issued and pend Dey" Buttery Det. sand ing. Licensed for ama = m4 5 Volts Gas C ai teur, experimental and tent Detec’ $5.00 entertainment use in -li—1 ——& 25 amp radio communication Bry Entters pet ie Any other use will be Home Office : C-12—Similar to C-11 182 Second Street 154 W. Lake Street 30 Church Street [} with standard basesé

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OPPORTUNITIES IN RUBBER No.1 An Acid-Resisting Material Are you acquainted with the versatility of rubber as a material for mechanical uses? Do you know— That rubber is the most practicable acid resisting material? That muriatic acid tanks lined with rubber have been known to continue in service for over 20 years? That the most successful portable railroad tanks for muriatic acid are lined with rubber? The B. F. Goodrich Rubber Company has led the way in applying rubber to this use. It is an example of only one of many ways it may be adapted to your problems. We offer the cooperation of our Research Department to develop ideas for new applications. THE B. F. GOODRICH RUBBER CO., Akron, Ohio ESTABLISHED 1870 Goodrich cMecha nical RUBBER, GOODS “Best in the Long Run”

AMERICAN Radio Notes The Invisible Loud-Speaker.—Along | with the tendency to place all radio equip- ment in a fine cabinet so as to find a place for it in the living-room, there is a tendency to place the loud-speaker in a cabinet. Sev- eral of the present offerings are in the form of attractive cabinets, provided with a scroll | and sereen front. Just as in the case of | the modern phonograph, it seems almost cer- tain that the awkward loud-speaker horn must eventually disappear into a cabinet. | Radio Frequency in a Handy Package. —There has lately appeared on the market a vario-transformer which simplifies the problem of radio-frequency amplification. Instead of having a transformer with fixed windings, this vario-transformer has an ad- justment which tunes it accurately for all wave-lengths between 200 and 600 meters. Perfect shielding and pig-tail connections assure clear tones. Furthermore, the am- plification is uniformly maintained through- out the broadeasting range. This vario- transformer is put out as a separate instru- ment, aXd also in conjunction with a socket and rheostat, all mounted on a neat base. | Keep Matches Away from the Charg- | ing Battery!—It is not generally known, | unfortunately, that a storage battery on charge is giving off hydrogen gas, and that this when mixed with the oxygen of the air, forms an explosive. For this reason one should keep one’s face and lighted matches away from the vent of a battery while it is on charge. The battery is sufficient to permit the escape of the hydrogen gas, under normal conditions. In the presence of a flame, however, hydrogen gas, mixed with oxygen, may ignite and the battery may very well be blown to pieces. One should use an electric flashlight in looking into the charging battery to see the level of the electrolyte in each cell. What Resistance for the Rheostat?— One of the several questions which arise in the construction of a home-made receiver is

gas, the resistance of the rheostat. There are three general classes of rheostats, so far as resistance rating is concerned. Hence it becomes necessary to classify the tubes in three groups, in selecting the proper rheo- stat. A rheostat of 6 ohms is necessary for tubes of 5-volt rating. A 20-ohm rheostat is used for the tubes of 3-volt rating. <A 30-ohm rheostat is used for the 114-volt tubes. As for the carbon rheostats, they may be used with any type of tube since they have a range of resistance from zero to 30 ohms or more, thus covering the com- plete range of resistances. Regeneration and Radio Frequency.— While it is true that the is making way for the cuits, the fact remains that the ative circuit, when properly constructed, between two and three radio-frequency amplification. Beyond doubt, it is the most economical type of circuit, but, unfortunately, in the hands of the inex- perienced operator it is allowed to oscillate and therefore becomes a miniature trans- mitter to annoy the radio audience in the immediate neighborhood. When it comes to loud-speaker operation, the single-circuit re- generative receiver, together with two stages of audio-frequency amplification, gives the best results at the lowest expense. It is unfortunate that regenerative sets are in the hands of so many unskilled laymen who have made this otherwise efficient type of receiver a perfect pest to broadcast listeners. The American Telephone & Telegraph Company’s Suit against the operators of the local WHN station in New York for the infringement of radio patents, is a mat- ter of considerable concern in radio circles. It appears from what has been stated by the telephone officials, that the whole purpose of the present suit is to protect the patents of the telephone com- pany, which are being infringed with im- punity by many broadcasters. On the other hand, numerous broadeasters have come for- ward with the charge that the telephone company is seeking a monopoly of the air, to the end that it may place broadcasting on a strictly commercial basis for its own gain. This charge is vigorously denied by the telephone company. At the present writing it is unwise to comment one way or the other. There is no doubt, of course, that the telephone company’s patents are be- ing infringed by hundred of broadcasters. There is no doubt, too, that there are too many broadcasters, especially of the medi- ocre kind. But whether it is wise for the radio-frequency cir- old regener designed separate stages of small vent of the | the |

| regenerative circuit |

and | gives an amplification equal to | officially May, 1924

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SOLDER WITH INSULATION At Least 1,000 Miles More Distance is the usual reward if you can solder without im- pairing the insulation of your set If you are building a radio-frequency amplifier you should read our free booklet: “HOW TO SOLDER RADIO SETS” Write for it. THE VALLEY FORGE CHEMICAL CO. Valley Forge, Pa. Worthy of Their Reputation Sheer merit, proven through the acid test of service, has won for Burgess Radio Batteries a world-wide repu- tation for quality, expert construc- tion and superlative performance. ASK ANY RADIO ENGINEER BURGESS BATTERY COMPANY Building. . CHICAGO Harris Trust Building - - - Laboratories and orks Madison, Wis. Niagara Falls, Ont,

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goer MA tele] broa for alth lega ey man Tesi and and now of a of p radi deme greal anno to t 12,06 one-t does able whic the a wires or n Such imme detai the v resou Th issue and trans parat ton |] as st types and-p is th frequ plific: the u come give | simila know! audio- ducto) trollir and it tuner, 600 pr dense! super- ceivin, She tracti! Wirel means able t tances is ine broad reache feat grams and r statior Britai Seand two y high-f: assists organi house repeat Hastir since wave | at Ea: the tr: cast W about the e antenn wave | feet, i antenn great short-v and th mately paring waves. land o1 a freq same re = of 32¢€ hiteane frequet same } cast w dayligl carryir short 1 effect i

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May, 1924 telephone company to make the path of the broadeasters still more thorny by charging for the use of patents, remains to be seen, although there can be no question of the legality of such a move. Tesla and His “Wireless Power.”—It is many years since we have heard from Nikola Tesla, the well-known electrical inventor and the father of numerous rather startling and fantastic ideas. At the age of 67, Tesla now states that he is on the very threshold | of an age which will see the transmission of power over vast distances by means of radio. “Since my original experimental demonstration,” states Tesla, “I have made great improvements and can now definitely announce that the loss in the transmission to the greatest terrestrial distance, say 12,000 miles, will not amount to more than one-quarter of 1 per cent. This, of course, does not take into account certain unavoid- able losses in transmitter and _ receiver, which will amount to about 4 per cent in| the aggregate. In conveying energy through wires the loss amounts often to 20 per cent or more, and the distances are limited. Such a plant could be put into operation SCIENTIFIC AMERICAN 357 immediately, for I have developed all the | details. I shall commence construction in the very near future, relying upon my own resources.” The Transinductor.—In the February issue ofthis journal, under “Inventions New and Interesting,’ there was described the transinductor. This new transforming ap- paratus was designed and invented by Clin- ton H. Hulbert, instead of E. W. Kersten as stated in the article. One of the latest types of transinductors is applied as a push- and-pull radio-frequency transformer. This is the first instance of push-and-pull radio- frequency amplification. Push-and-pull am- plification applied to radio-frequency with the use of transinductors is said to over- come distortion, increase amplification, and give super-selective tuning; in fact, it has| similar advantages to those of the well- known audio push-and-pull amplification in audio-frequency. The push-and-pull transin- ductor by means of one dial is capable of con- trolling the magnetic inductance, capacity, and iron. It acts as a complete wave-length tuner, at maximum efficiency, from 200 to 600 meters. It requires no variable con- denser or any other control to bring ouf super-selectivity and sensitiveness in re- | ceiving, according to the inventor’s claims. Short-Wave Transmission is now at- tracting no little attention. According to Wireless Age, broadeasting stations, by means of short-wave transmitters, are now able to send their programs over great dis- | tances by day as well as by night. This is indicated by the results of short-wave broadeasting experiments which have lately reached almost unbelievable results. The feat whereby American broadeasting pro- grams are repeated on these short waves and received and rebroadeasted by English | stations, thus reaching the peoples of Great Britain, France, Germany, Belgium and the} Seandinavian countries, is the outcome of two years’ experimenting and perfecting of high-frequency apparatus by Frank Conrad, | assistant chief engineer of the Westinghouse | organization. Last October the Westing- house company inaugurated the first radio repeating station, known as KFKX, at Hastings, Nebr. This repeating station ever since has been receiving the high-frequency wave sent out by the parent station KDKA at East Pittsburg, Pa., simultaneously with the transmission of the usual KDKA broad- east wave. One of the most striking things about the short-wave transmitting set is the extremely short antenna used. The antenna at KDKA for use with the short- wave transmitter is slightly in excess of 35 feet, in striking contrast with the 200-foot antenna used for regular broadcasts. The great difference in frequency between the short-wave broadcasts (under 100 meters) and the common wave length band, approxi- mately 360 meters, can be noted by com- paring the kilocycle frequency of two such waves. KDKA commonly transmits to Eng- | land on a wave length of 94 meters, which is a frequency of 3,200 kilocycles. At the same time KDKA is broadeasting to its regular broadcast audience on a wave length of 326 meters, which is a frequency of 960 kilocycles. Tests have proved that the high frequency broadeasts go farther with the same power input than the ordinary broad- cast waves. It has also been proved that daylight has little effect, if any, on this carrying power. These two qualities of the short waves are going to produce a marked effect in the future of broadcasting. "FT 2S HEE TE FTULi OF FHiriRnest FOV 2,EOULDN’ FT Mis. Get ready now for summer radio Your radio batteries have served you well and faithfully over the long winter months. Now a great radio summer is at hand. To enjoy summer radio at its best, equip your receiver with the best batteries you can get. Put in new Eveready Radio “B” Batteries and see what wonderful, long-lived service they will give. Made especially for radio use, Eveready “B” Batteries will operate the loud speaker at maxi- mum volume for long or short periods, depend- ing on how rapidly the current is taken out of them. Packed full of pep and punch and go, Eveready “B” Batteries pour out their power the moment you turn on the tubes. Scientifically made for long-lived radio service, the cells renew their vitality when idle—responding instantly with fresh vigor. Eveready ““B” No. 767 is the standard amplifier “B” Battery, and gives 45 powerful, dependable, zippy volts. Five sturdy Fahnestock Clips make this big ““B” Battery available for soft detector tube use as well—varying the voltage from 1614 to 2214 as required. Insist on Eveready ““B” Batteries, remembering that they are the product of thirty years of experi- ence and know-how in battery making. Designed and made under the supervision of the finest electro-chemical laboratory known to science, the quality and efficiency of Eveready Radio Batteries are assured. For maximum battery economy and service, buy Eveready Radio Batteries. Manufactured and guaranteed by NATIONAL CARBON COMPANY, Inc., New York—San Francisco Headquarters for Radio Battery Information Canadian National Carbon Co., Limited Factory and Offices: Toronto, Ontario 1 EVEREADY No. 766 “B” Battery, 224 LJ ® volts. Six Fahne- stock Spring Clips — —they last longer Eveready Pi volt corage oA Battery Eveready *A”™ Dry Cell e best battery for use with dry cell tubes No. 764 The Space Saver Vertical 22 4-volt “B” Battery No. "771 “C”™ Battery Clarifies tone ff and prolongs a “B” Battery life No. 767 “B” Battery, 45 volts Variable taps Fahnestock Clips Informative and money-saving booklets on radio batteries sent free on request. If you have any questions regarding radio batteries, write to G. C. Furness, Manager, Radio Division, National Carbon Company, Inc., 216-218 Orton Street, Long Island City, N Y.

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858 SCIENTIFIC AMERICAN 88% timate of business in $10 communi§ties are sup plied minety days in ad vance through BABSON’'S REPORTS OF 2,970 such specific estimates made during the last 27 months 88% have proved correct Gassowe Rescate Write for Babson Report R40 —-Gratis LARGEST ORGANIZATION OF ITS CHARACTER IN THE WORLD | | 4 7 Good Markets Twenty-Seven cities are buying readily! Twenty industries are unusually active. They offer better than average markets for all sorts of goods and services. These fertile fields are indicated cleanly by the current analyses of every sales territory and of all leading industries, contained in current Babson Reports Thousands of men, co-operating through this organization, depend upon this infor- mation to help them increase sales and reduce costs. These same facts offer you an opportunity for increased volume during the next go days! The pro-rata cost of this service is small indeed—results considered. The BABSON STATISTICAL ORGANIZATION Babson Park, Massachusetts | perhaps the most popular, for aside from its May, 1924 “This is Station es (Continued from page 354) that the weakest radio energy is built up many fold before being turned over to the detector for conversion into audio-frequency eurrent. The detector is very much like the trigger of a gun, in that a certain amount of force must be applied before it will oper- ate or “shoot.”” Thus the weak radio waves may not be strong enough to “trigger” the detector tube, and no amount of audio-fre- quency amplification after the detector will be of any avail if the deteetor has failed to operate or “shoot.” There are all kinds of radio frequency am- plifier sets in operation. The neutrodyne is LARGEST ORGANIZATION OF ITS CHARACTER IN THE WOALD Seg i aera 7 : 4 iss’ ans Riu — ee ee f eet SHEIM SHOE CF LoRsHEM Shoes give loyal service — each succeeding pair maintains the reputation of the name—your next pair will serve you as faithfully as the first. eMost Styles —TGen “Dollars ‘The Bristol—cM-141 One of Gwo Glundred Styles. Booklet of Styles on “Request. Tue FrorsHem SHor ComMPANY Manufacturers -« CHICAGO pe Toren SHOE 4 remarkable efficiency it has the marked ad- vantage of being absolutely stable in adjust- ment. With its three tuning controls once charted for the various stations, the oper- ator of the set can always tune in any | desired station by setting the three dials to | the numbers indicated on the chart. | | There are two broad classes of radio fre- | quency amplifiers, namely, the tuned radio} | frequency, in which the successive steps or | “stages” are tuned, and the untuned type in| | which the coupling of one step or “stage” to the next is accomplished by special trans- | formers of fixed wave-length. | The old principle of regeneration, which | makes the detector tube serve as a detector | and a radio-frequency amplifier at the same | time, is still found in the latest types of receivers. However, certain precautions are taken so as to prevent the regenerative action of the detector tube from emitting a wave when the regenerative action is forced. The combination of so-called tuned radio | frequency and regeneration is quite popular | | today. There are receivers in which the vacuum tubes are made to work at two jobs at one time, just as in the regenerative set. Thus in these sets, which are known as reflex sets, the same group of tubes are employed first as radio-frequency amplifiers and then as | audio-frequeney amplifiers. Thus it becomes possible to make a given number of tubes do the work of twice that many when using | the conventional methods. Of radio cireuits, there is no end. Basic- ally, however, there are about a half-dozen A Vital Factor If reliability is important in the larger and more conspicuous apparatus, it is even more so in the small and often concealed parts, where a flaw will nevertheless prevent absolutely the working of the set. That is why Kellogg miniature condensers are designed and manufactured with the same painstaking care as the famous variable condensers and other larger parts. Our miniature condensers are all made exactly the same size mechanically, being 17% inches overall, with a tip diameter of 3, inches. Electrically they are built in seven different capacities from 250 micro- microfarads (No. 506) up to .01 micro- farad (501). The plates are of heavy tin foil insulated by specially prepared paper of high dielec- tric strength. This is tightly rolled and the copper terminals soldered to the brass end pieces which are securely crimped to the fiber cover. No. 501.01 M No. 504.0010 M. F. No. 502 “05 M. 4 lo. 505 .0005 M. F. No. sos 0025 M. F No. 506 .00025 M. F No. 507 .006 M. F. Jse—Is The Test KECLOGG SWITCHBOARD & SUPPLY COMPANY 1066 W. ADAMS STREET CHICAGO, ILL. circuits. The layman is bound to be con- |fused when confronted with dozens upon dozens of different circuits, accompanied by the most fantastic claims. Little wonder, | therefore, that many laymen prefer to hold | back from buying their radio set, because they have a distinct “hunch” that the ideal set has not as yet been evolved from the} | bedlam of receiving circuits. Yet the fact | remains that our fundamental circuits of to- day are highly efficient, and we are not likely | to replace them in a hurry. Putting the Atom to Work | (Continued from page 306) electrical, or in other words an etherial property; that inertia or massiveness is not | due to something in the ultimate unit of | matter, but to something surrounding it. The observed inertia of an electric charge may be ascribed to the ether which it carries with it. But that is too vague and indefinite | to be useful. It is preferable to say that | inertia is explicable in terms of electromag netism: that every electric charge has a cer- | tain mass associated with it, and that in an aggregate of electric charges their masses are added together. But here comes the delicate point. When electric charges are squeezed close together they interfere with each other to some ex- tent. The positive and the negative tend to | neutralize each other. If they could be| jammed into complete coincidence it must be supposed that they would obliterate each other. That, as far as we know, is not pos- sible. But they can approach very near each other. And in that case their effect is neu- tralized as regards distant observation, or at least almost neutralized; and their inertia is | diminished. Two opposite charges at a rea- sonable distance apart will have double the inertia of one. But if you pack them too} tightly together, the combined inertia will be less than double. Some of their mass} will apparently have disappeared, gone out of existence. Now we said that a helium nucleus, if it eonsisted of four atoms of hydrogen, must | have those four atoms packed very tightly | together. There are four positive charges | held together with two negative charges; and | the tight packing would result in a dimin- lished mass, a loss of weight; the aggregate | will not weigh four times the original unit, | but something less. In other words, not four | Magnified 225 Diameters This is what the tip of a fly’s leg is like when seen thru the Ultralens Microscope At last the high powered microscope is within the reach of all who wish to study, observe and ex- ‘7 5 0 periment with the vast world of minute objects that are in- visible to the naked eye. A re- markable discovery enables us se to manufacture the Ultralens Canada 5c. extra Microscope (magnifies 225 diameters) for one-eighth the usual cost. Easy to Use! Any amateur can immediateiy start using his Ultralens to examine the edge of a razor, the mesh of a cotton shirt, the bacteria in dirty water. No technical training required yet hundreds of scientists and teachers are using this instrument today. It is at once interesting, instruc- tive, and scientific. Gives enormous magnification and perfect definition. COMPACT The Ultralens Microscope comes packed in a beautiful Bakelite case with full in- structions that anyone who can read can understand. Lenses of 125 x and 325 x objectives can be furnished at $1.50 each. ORDER TODAY Order direct from this advertisement and get your Ultralens Microscope now. Fully guaranteed. If, however, you desire more information before pur- chasing we will gladly send free descriptive catalog. SCIENTIFIC APPARATUS CORP. Dept. 102 MILTON, PA. tin is wo but bri oth but ing hyc I of sev dro trin I trac con: are E whi ene} app of | mus Nov neit labo vert be a I ex W this phys sion, ener terve socia thou whic also, techr of th or rm what the : A wi ulate ident Kelvi vidua open It ce an et Bu culati thing the s grain work energ small with | 600 te If 1 tion « sultin, gen is not th seven appea thougl yet th gigant other But drogen heavie yet it done, | the in presen energy counte stars |; fractio count heaven ones a energy counter us, by Ordi togethe loose k amount into até kind of atoms j violent some of hotter. fronting is no di the ling human even a § in the ¢ quences cording time att

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May, 1924 SCIENTIFIC AMERICAN 359 times 1.0077, but only four times 1. That, is the kind of thing to be expected. That would account for the disappearance of the 0077 which belongs to hydrogen isolated, but not to the hydrogen used as the building brick for other atoms. Helium and all the other atoms may be composed of hydrogen, but of tightly packed hydrogen. And, aecord- ingly, hydrogen in combination is 1, while hydrogen free is 1.0077. But this looks as if matter could go out of existence. How is it possible for the seven or eight parts in 10,000 parts of hy- drogen to disappear? What about the doc- trine of the indestructibility of matter? But we have never yet said that it left no trace behind. That is just what we have to consider. If matter ever disappears, what are we to expect instead? Here comes in the theory of relativity, which states that in some sort matter and energy are interchangeable. If energy dis- appeared, we must expect to find generation | of matter; and if matter disappeared, we must expect to find evolution of energy. Now, so far as we have gone at present, neither of these things has been done in the laboratory. No one has seen matter con- verted into energy, or vice versa. It would be an important day when it was done. But * : tH . » Yr \ (as I expect. that some day it will be done. ’ |i We might stop to ask for a minute how \ SS Py ° ° , = eS S .) this can possibly be understood. What RECASS: ek pnhysical notion can we form of the conver- _ inns sion, or inter-relation, between matter and energy? In my view, only through the in- tervention of the ether. The ether has as- ec sociated with it an absolute well-known, though great, velocity—the velocity with 1eé as roa aS& which it can transmit waves; but which is also, in my belief, a constitutional velocity, I 1¢ technically called the velocity of light. Parts of the ether which are circulating in vortex or rotational motion with this velocity, are what we must look to for the explanation of the fundamental part of atoms of matter. a — ge ne Sete _ The bearing problems of industry machinery, and _ giant reduction ulate solic yroperties and wouk ave a ° : identity of its own; as Helmholtz and Lord are unusual and widely different. gear:s. — long so showed. LePasse: > tom Loads vary. Speeds vary. Installa- In each case longer bearing life, yvidua circulation 18 interrerec with or . . opened out, its energy becomes conspicuous. tions vary. The bearing manufacturer greater freedom from trouble, a sav- It ceases to - a matter unit and becomes must study each bearing application. ing in power, and simplified lubrication an energy unit. . . . . . But the energy of anything moving or cir- Timken engineers, in co-operation have been accomplished. rege tring a pes at with industrial engineers, have de- Timken engineering co-operation is avail- the square of that velocity. And even a termined the proper Timken Bearing able to any manufacturer. With the expe- aor _ Ly men ing 2 that speed could do for such widely different applications — gained in eee ee a ing ) qui hi ousands tf) ons. . f a > aps energy of one-tenth of a milligram, the se wine cers, conveyors, dectic on oid be of value to. a smallest visible or weighable speck, moving motors machine tools shaft han ers our experience cou ‘ willie va ue w you. with the speed of light, equals that of a load 3 ’ g ae This engineering help is yours 1f you ask for 600 tons falling a mile. overhead trolleys, wood. working _ it on your business stationery. If then the whole of any perceptible por- tion of matter disappeared, the energy re- sulting would be prodigious. When hydro- THE TIMKEN ROLLER BEARING COMPANY, CANTON, OHIO gen is packed into helium, the whole runs not the slightest risk of disappearing. But Ordinary combustion is due to the packing | together of atoms into molecules, a very loose kind of coupling, giving a very small amount of energy. The packing of atoms into atoms is a much closer and more violent kind of phenomenon. And the undoing of atoms into non-circulating ether is the most seven or eight parts in every 10,000 do dis- appear. The 1.0077 becomes one. And PRINCIPLE mg Bee ey The basic reason for the succes of Timken in industry = ; ; ‘ can be definitely traced to the Timken Dual Duty prin- gigantic that the result would put all our ; ‘. Fé 2 : other sources of energy to shame. ciple—the capacity to take, in one bearing, both radial Sut we have not learned how to pack hy- loads and thrust loads. In addition, the tapered design drogen into helium or into any other of the of Timken Bearings makes them adjustable for any wear heavier atoms—as yet. No, not yet. And which might develop after years of uninterrupted service. yet it would appear that it must have been done, some time and somewhere; perhaps in the interior of stars, certainly in ways at present unknown. And, if so, some of the . . energy associated with matter may be ac- - , counted for. This is believed to be why the — stars are hot. I suggest that some small : violent of all. The sun is hot enough: but some of the stars are several thousand times fraction of this outburst of energy may ac- ones are hot, roughly speaking. The total us, by any except what is here suggested. hotter. So that the amount of energy con- fronting us in space is majestic. Sut there is no difficulty at all in accounting for it on even a small fraction of the energy contained in the atoms of their own planet, the conse- quences will be beneficent or destructive ac- count for their rapid motion. All the energy is beyond anything that ean be ac- the lines here indicated. And if ever the cording to the state of civilization at that L L ke R 4 E A ee I F [ G . heavenly bodies are moving, and all the big counted for by any of the forces known to human race get hold of a means of tapping time attained. © 1924, T. R. B. Co.

Page 60

860 ree weeks saved ~all extra profit When you estimate a job will take 7 weeks and you bid accordingly—then you start your outfit at work and actu- ally finish 3 weeks ahead of schedule, “it’s a grand and glorious feeling.” EVERY DAY SAVED IS CLEAR PROFIT. Chas. D. Moore of Pontiac, Mich., finished widening and grading the Dixie Highway north of Pontiac, 3 weeks ahead—thanks to the perform- ance of his Bay City 16-B Crane Exca- vator equipped with “THE TRUSTWORTHY ENGINE” Mr. Moore says, “No engine replacement or repairs were necessary during the entire job. The material excavated was hard-packed gravel.”” How’s that for “digging through"’? Be sure your new equipment is equipped with Climax Trustworthy Engine. Write for Catalog CLIMAX ENGINEERING CO. 34 W. 18th Ave. Clinton, lowa P { worthy po Used as Standard Equipment by— Kansas City, Mo Equitable Asphalt Maintenance Co **Satisfies the craving in my mind as a plank steak would satisfy a hungry hobo.’’ So writes a Hartford man about his SCIENTIFIC \MERICAN subscription, assuring us that to miss a single issue would be unthinkable to him. ‘That is exactly our idea in suggesting this coupon to you in case you are not now a regular subscriber. Don’t depend upon chance of buying a copy when for $2 or $4 expenditure you can have the SCIENTIFIC AMERICAN coming to you regularly the 2oth day of each month. A good magazine is hard to find, a more interest- ing Or important one impossible. Be your own judge—tear this corner off today and start SCIENTIFIC AMERICAN on a journey to your home each month. SCIENTIFICAMERICAN Munn & Co. 233 Broadway, New York SCIENTIFIC AMERICAN PUB. CO. Mann & Co., 233 Broadway. New York Please enter my subscrip tien to the new menthly “Scientific American” for one year for which I enciose $4.06, or for six months, for which I enclose $2.00. | SCIENTIFIC AMERICAN When, Where, Why? (Continued from page 312) traflic. This is a constructive suggestion | for preventing accidents, and one which| could not possibly be made in the absence of | complete figures for all the accidents of a| whole state; for in the absence of such | figures, your guess that most accidents oc- | eur to new ears is as good as Commissioner | Stoeckel’s guess that most oecur to old ones. Much discussion goes on, in and out of | the daily press, as to just how much reckless | | driving and reckless walking there is, and | about three minutes to find out for you just | what | ment, to carelessness of an occupant of the | | fication. | the conditions ; | Pretty complete catalog of the motoring sins, just how responsibility for the sum total of automobile aecidents should be divided. If you ask this question in New York, again your guess or my guess or anybody’s else guess is just as good as that of the Police Commissioner or the head of the city’s court system. But if you ask it in Connecticut, there is no guess-work at all in the answer. It will take the Commissioner's office staff percentage of the state’s motor acci dents are due to recklessness of the operator ; what percentage to carelessness of a pedes- trian; what percentages to the carelessness of a “contributor” (see below), to bad equip- ear, to miscellaneous causes involving no apparent carelessness at all. Under operating recklessness the Connecti- cut system of tabulation lists twenty-one items, and it will be interesting to go down this list. Intoxiedtion; speed too great for eutting in; passing a stand- ing trolley; passing on curve, on hill, on wrong side; trying to beat a train to the} crossing; cutting corners; parking on the| wrong side; failure to grant right of way; inattention; following the car ahead too closely ; runaway car through failure to set brakes, through cranking while in gear; con- fusion; skidding; careless backing; inexperi- ence: driving on the wrong side of the road. Could you draw up so exhaustive without a file of accident is it not? a list of “don'ts” reports to refer to? The pedestrian displays seven ways, according to the official classi- He gets intoxicated: he gets con- fused; he plays in the street; he steps from behind another vehicle; he boards or leaves | a trolley improperly; he coasts; and he| crosses the street at a time or place where he shouldn’t or without due attention to his} earelessness in course. “Contributors” bringing on accidents are the motorman, the cyclist, the teamster, the gateman or flag man, the push-eart man, the runaway horse, the animal of miscellaneous sorts, and the unknown operator of another car who suc- | ceeded in getting clean away. Defective equipment of course usually means bad brakes, glaring headlights, or inadequate headlights. It may also be the steering gear; and tires today are sufficiently reliable to make it reasonable to presume that one that blew out was defective within the possible knowledge of the owner. Ob secured vision is defective equipment when not due to the rain or snow or fog that is actu ally in operation at the moment; if it is clear, you are responsible for being able to see through your windshield. Then there is a miscellaneous category here. The occupant of the car may display carelessness in jumping on or off a moving vehicle, in the fact that his very presence there constitutes stealing a ride, or in inter- | fering with the operation of the car. Under miscellaneous causes chargeable to | nobody in particular are road obstructions, weather conditions, unprotected railroad crossings, and ignition of the gasoline. Now it is self-evident that the very anal- ysis of accidents among this series of causes is a mighty edueational undertaking. When we ean, in addition, state exactly what per- centages of the accidents occurring in a given area within a given time are to be attributed to each cause, we have made a very long step indeed toward prevention. We know in what direction to turn legisiation, propa- ganda, popular education. We know what it is that we are trying to prevent, instead of merely guessing. In the present article, no attempt is made to show what percentages of accidents are due to the various causes; we leave that for future treatment. What we are pounding on here is the practical necessity for just such a census of accidents as Connecticut’s, based upon just these | data—reports of every accident, from those | involved. } If the figures are available as a means of keeping the bad cars off the road, they whose carelessness aids in own | map. }numeral “1.” If no further smash May, 1924 are equally available as a theans of keeping off the bad drivers. The Commissioner has a file in which are kept, for identification purposes, little index cards showing names, addresses and license numbers of all Con- necticut’s licensed operators. When the year runs out, these are not destroyed; they are transferred to a permanent file, in which they are arranged alphabetically, and in which appears a complete record of every person who has been licensed to drive in Connecticut since this file was started. Ulti- mately, of course, it will have to be weeded out up to a certain arbitrary date; but this will not rob it of its value. The essential details of every accident are entered upon cards of corresponding size to the license cards in this file, but of differ- ent styles and colors; and one of these cards is put in the file of each operator involved. Trials, suspensions, revocations—everything that constitutes part of one’s record on the road—all this goes in. In dealing with every accident of today and tomorrow, the Commissioner has available this complete record; he can make it availabie to the court, or he can avail himself of it by demanding that cause be shown why the license should not be revoked. In some jurisdictions you can go right on having the same sort of accidents indefinitely, and none of the old ones will bob up in court to prejudice your showing in the latest one. But not so in Connecticut; if you are tem- peramentally unfitted to drive a car on the public roads, the Commissioner will find you out. So much for the cause of the accident, the ear, the driver. There is one other impor tant element, the place. Whatever the cause which the judicial sifting-out process hits upon as the proximate one, it is usually the case that the physical conditions sur rounding the scene of the wreck made some contribution. The most reckless driver does not have a smash-up every minute, or even a narrow escape; his close shaves and his smashes occur at points where there is some physical hazard, however minute, lying in wait for him. Commissioner Stoeckel has formulated a program of identifying these physical haz ards, and so far .as possible eliminating them. Large-scale maps of the leading cities —New Haven, Bridgeport, Hartford, ete. are posted on his walls, and every time an accident occurs in one of these cities the spot at which it happened is tabbed on the Ultimately the system may be ex tended to cover the whole state; already it has been extended to numerous cities which it did not originally cover. For the year’s first accident at a point (usually a corner, of course), a tri angular-headed pin is inserted, carrying the fiven comes at that spot during the year, the original pin is not disturbed. If a second follows the first, the “1” pin is replaced by one of the same shape that says “2.” When the roll for a given point reaches six, the shape of the pin changes, and the numerals from “6” upward are carried on square heads. It is then easy enough to pick out the where accidents are habitual from where they are not habitual. Along toward the end of the year, the Commissioner's accident map for one of his cities looks like the picture on page 312. As soon as the accident map makes it clear that accidents are in the habit of coming at a given corner, an inspector is sent out to look that corner over and find its physical defect. If the bulk of the smashes have occurred at night, the illumination is naturally suspect, and he looks for glares or shadows. Other suspicious parallelisms between the several accidents at a given spot furnish other leads. Sometimes it is one thing, sometimes another; always the inspector will find out what it is, and usually, unless it be pure unadulterated congestion, a remedy can be found. One of Hartford's plague spots was a five-corners, and the danger was taken out of it by routing all traffic through it circularly. Again the pro- hibition of left-hand turns spells remedy. Sometimes it may be found that a rough spot in the pavement distracts the driver's attention at the critical moment and renders places those him peculiarly liable to getting hit; again the combination of grade and intersection may be one ecaleulated to make the unin- formed driver lose control temporarily, or there may be a blind spot which ean be eliminated. In one ease, the police authorities of a city of some 40,000 were in total ignorance of the existence of the worst trap in the city; when they were informed by the Com- |S Sezereoewmetorreens pg Str: the full pou I rect out o oO 899 | L

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May, 1924

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62 | SCIENTIFIC Every Executive Should Have This Book In this booklet you will find helpful suggestions that will aid in the solution of many of your manufacturing problems. The booklet gives typical examples of how manufacturers in widely different lines have lowered their production costs, eliminated excess weight and expensive machining operations and have gained numerous other advantages by replacing castings and forgings with Stampings and Pressed Metal parts. It may be that a closer analysis of your product will show that a re-development in pressed metal of one or more of its parts will in economies that you cannot afford to ignore. G.P.aF. SERVIC “KNOWING HOW SINCE ‘Si" result The facilities of our vast plant of 15 acres with its complete mechanical equipment and more than 1,200 workmen are at your dis- posal. Our more than 42 years’ experience in this specialized work gives assurance that we are well qualified not only to advise you intel ligently but also to execute promptly any order, no matter how large or how intricate the design may be. Write for FREE booklet today Sent on request to all interested in lowering production costs. Address Geuder, Paeschke & Frey Co. 351-357 West Ohio Street Chicago, Illinois 1331-1731 St. Paul Avenue Milwaukee, Wisconsin | tooth so why not put me to the test. Guess You’re Running Machines Right —But you get it down to a science when you get the figures on each move, each turn of a shaft! Veeder Counters don’t record what you think your machines are doing. ‘They don’t register the busy appearance of machine operators. You do get the proof of right- way and wrong-way management from a eeden COUNTER The large Set-Back Rev- lution Counter ai right ss than % actual i ] ’ l Re 4 t ‘ l ’ full si The Set-Back Revolution Counter above re- cords the output of the larger machines where the revolu- tions of a shaft record operations, or output. Counts one for each revolution, and sets back to zero from any figure by turning knob once round. Supplied with from four to ten figure-wheels, as required. Price, with four figures, as illustrated, $10.00 (subject to discount). The Small Revolution Counter at left records the output of smaller machines where a shaft revolution indicates an operation. Though small, this counter is very durable ; its mechanism will stand a very high rate of speed, making it especially adapted to light, fast-running machines. Will subtract if run backward. Price, $2.00. There ? a VEEDER to fit every machine—and every need in your production-scheme. The Veeder booklet shows 80 pages of counters; write for this free guide to greater production. | The Veeder Mfg. Co.., 18 Sargeant St. ssclltlteas Hartford, Conn. | lower 6th left in the other. |} teeth are all of the AMERICAN be considered reasonably accurate, it should | have found those predominant and highly developed sources of infection. The den- tist’s records show that, contrary to the electronist’s findings, the lower 6th year molars were missing. It must be apparent that the electronist has failed to score even a modest success in | this diagnostic test. This is rather disap-| pointing, in view of the previous correspond- ence we had with the Los Angeles gentleman, | reading, in part: “Now as I have said before I know the method will diagnose an abscessed Send me on a specimen of the handwriting on plain white paper and in plain envelope of one or two people whom some dentist will vouch for their having abscessed teeth. Use separate envelopes to avoid mixing the ‘vibrations’ and let each patient write his own name or anything he pleases, send on to me and I will send you back name of the tooth of each patient. Dr. ...... here has always done this stunt correctly and I see no reason why he should fall down with you.” Not until actually called upon to make a test is there any suggestion of pos- sible failure; then this suggestion is put) forward quite strongly! Aside from the obvious failure of the elec- tronist in this particular test, there is another highly significant fact which bears considerable thought. It will be noted that the electronist found the upper 6th right in one case, and the lower 6th right and the In effect, these same kind. Perhaps this is merely a coincidence, but at any rate | it is a possibility for which we were quite | prepared in advance. A brief review of the records in our co | operating dentist’s office disclosed the fact | that a very large percentage of dental work | is done on the sixth year molars. | their The den- tist’s explanation as to the cause for such preponderance of trouble in those specific teeth, is that the 6th year molars are the first large teeth in the mouth, usually making appearance at the age of from five to six years. Furthermore, our co-operating dentist informs us that in any diagnosis of teeth infections or ailments without a com- plete examination, he would say offhand that the trouble existed in the 6th year molars. Our Abrams Investigation Committee fails to be impressed by this test of localization. In view of the electronist’s claim of 80 per cent aceuracy in his diagnostic work, we are frankly disappointed. As for the small amount of energy derived from handwriting as compared with a blood specimen, we can only state that we sent precisely what was | asked for. Furthermore, certain electronic workers have time and again stated that handwriting was as effective as blood speci- mens. This test must stand as our only evidence of the efficacy of the electronie localiza- tion work until other tests are entered into between electronic workers and ourselves. Again we solicit electronic workers to co- operate with us in tests to the end that we ean arrive at the real truth of the entire electronic controversy. The History of Engineering HERE comes to hand a most interesting volume, the Transactions of the Neweco- men Society for the study of the history of technology. This body. whose well indicated by the full name quoted, has its headquarters in Lon- don and the bulk of its membership is Brit- ish. The President of the Society assures us, however, that they are anxious to have the Society regarded as an_ international body, and that American members would be weleomed most cordially. We know of no such body in this country, and one whose interests lie in the field of technologie anti- | quities would find his fees well repaid by the | Transactions alone. Some idea of the scope | of these may be got from a statement of the more important papers included in the vol- | ume before us. We note discussions of the | early history of mechanical handling de-| vices, of Greek and Roman engineering in- | struments, of mechanics and engineering from Aristotle to Archimedes, of Timothy | Hackworth and the locomotive, of Heaton’s | steam earriage, of Gurney’s railway locomo- | tives (both of these from 1830), of Brun- | ton’s steam horse of 1813, and of several | other interesting items. In addition there is | included in the volume a very useful bibliog- |raphy of historical subjects, and it is the | intent to continue this in sueceeding volumes | | until it is brought down to date. The Secre- | retary of the Society is Mr. H. W. Dickin- son, M. I. Mech. E., the Science Museum, South Kensington, London 8S. W. 7. engineering and scope is May, 1924 PATENTS Trade-Marks Copyrights Designs 76 Years’ Practice Before the Patent Office If you have an inven- tion which you contem- plate patenting, or a trade-mark which you desire to have registered, we shall be pleased to have you consult us. We have thoroughly ex- perienced attorneys in our New York, Wash- ington, Los Angeles, Chicago and San Fran- cisco offices, with long experience in preparing and prosecuting both patent and trade-mark applications. Prompt, Conscientious and Efficient Service The SCIENTIFIC AMERICAN contains Patent Office Notes, De- cisions and other matter of interest to inventors— and particulars of recent- ly patented inventions. We shall be pleased to send, without charge, our Handbook on United States and For- eign Patents, Trade- Marks and Copyrights. MUNN & CO. PATENT ATTORNEYS Woolworth Building - - - - New York Scientific American Building - Wash., D. C. Tower Building- - - - - Chicago, Ill. Hobart Building - ~- San Francisco, Cal. Van Nuys Building- - - Los Angeles, Cal. Ph of ma bot ac tai con wh fee Irr the tur red pre the is | this ity, and C gic whi seve fect: liab] tage loid: the pour per tion ring, pree with all t drate solut hydr thou: sever catec one celler to ap a is of cloth or ce for t mann penti parts are d is obt subst: of lin while fire. the fir added first-r Umsei A ] orator produ which that t hexetc from hexeto ius pov Oils Stone Grasse tractio stones, methoe carbon ployed mable more, | almost monly possess action vent a kilogra works ture, that is tractio! mately remove that th and sol where |

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May, 1924 SCIENTIFIC The Service of the Chemist A Department Devoted to Progress and Achievement in the Field of Applied Chem istry Conducted by ISMAR GINSBERG, Chemical Engineer A New Disinfectant.—According to the Pharmaceutical Journal a new disinfectant | of excellent properties has appeared on the} market under the name of acrosyl. It is| both a saponified antiseptic disinfectant and | a deodorant. It is a cresol preparation con- taining 50 per cent tar acids, these acids containing 55 to 60 per cent of meta eresol, which is known to be a more powerful disin- fectant than phenol and the other cresols. Irritant properties have been removed from the tar acids during the course of manufac- ture, and the caustie action of the cresols is reduced by the fatty acids present in the preparation. The carbolic acid coefficient by the Rideal-Walker test is three. The odor is particularly pleasant for a preparation of this nature. It is made of a uniform qual- ity, has no corrosive effect on instruments and does not blunt knives. Colloidal Copper Hydroxide as a Fun- gicide.—Ordinary Bordeaux mixture, which is commonly used as a fertilizer, has several important disadvantages and de- fects. For example it does not stick and is liable to scorch. To remove these disadvan- tages it has been recommended that the col- loidal copper compound be used instead of the ordinary substance. This colloidal ecom- pound was prepared by the addition of a 10 per cent solution of caustic soda to a solu- tion of sulfate of copper, with constant stir- ring, any excess of soda being avoided. The precipitated hydrate was repeatedly washed with distilled water by sedimentation. When | all the salts were removed, the copper hy- drate on shaking with water, gave a colloidal solution which foamed, and contained copper hydrate to the extent of one part in one| thousand. It remained in suspension for | several weeks. Preliminary tests have indi- | eated that such colloidal copper hydrate in a one to five thousand concentration has ex- cellent sticking properties and is fungicidal to apple seale and blotch. Linoleum Adhesive Preparations.—It is often desirable to fasten linoleum or oil | cloth direct to the floor, which may be wood or cement, The cement that is recommended for this purpose is made in the following | manner. Twenty-five parts of Venetian tur- pentine are used as a solvent in which 30 parts of rosin and 70 parts of Manila copal are dissolved. After a homogeneous mixture is obtained which is achieved by he: ating the substances, it is mixed further with 22 parts of linseed oil. This mixing is accomplished while the first mixture is still hot and on the fire. Then the composition is removed from | the fire and 35 parts of denatured alcohol are | added. The result is a linoleum adhesive of first-rate sticking properties. — Chemische Umschau. A New Camphor Substitute.—The lab- oratories of the Bayer Co. in Germany have produced a new substitute for camphor | which bears the name of hexeton. It is s: rid | that the effects and properties possessed by hexeton are identical to those of camphor from the qualitative standpoint but that hexeton is approximately twice to four times as powerful as camphor. Oils from Olive Husks and Grape Stones.—The French journal Les Matieres Grasses contains a new method for the ex-| traction of oils from olive husks and grape stones. ‘The characteristic features of this method are as follows: In the place of using carbon disulfide, ethylene trichloride is em- | ployed because it is not nearly as inflam-| mable as the first named solvent. Further- more, the solvent power of this substance is | almost as great as those of the solvents com- | monly used for oil extractions. It however | possesses the additional advantages that its | action is very rapid. The losses in the sol- vent are only 0.5 to 0.8 liter per hundred kilograms of material treated. The solvent works better at a slightly elevated tempera- ture. The grape stones, and other material that is to be extracted, remain in the ex- traction apparatus for a period of approxi- mately two hours, which is long enough to remove practically al) the oily constituents that they contain. Then the mixture of oil and solvent is sent to the distilling apparatus where the ethylene trichloride is evaporated |eoloring mature citrus fruits. by the action of dry superheated steam. After the oil is freed from all traces of sol vent, it is collected through a suitable draw- off .cock and the solvent is recovered. The apparatus in the plant consists of a crusher, a dryer for receiving the cake from the crusher, and a boiler which is used for gen- erating the high pressure steam required for the distillation process. Two extractors are necessary, each having a capacity of from 500 to 600 kilograms. A multiple condenser completes the installation. With this appa- ratus it is possible to extract from 3500 to | | 4000 kilograms of raw material daily. The | condenser requires from 10 to 15 pounds of water per minute. The yield of oil is a little better than 10 per cent of the weight of the | cake. Electro-Magnetic Treatment of Steels. —An interesting paper was recently read be- fore the Institution of Production Engineers in London on the subject of the electro- magnetic treatment of steels. In this talk it was brought out that in the heat treatment | | of steel it is not only important to know the | temperature of the steel, but also the time | it has been maintained at that temperature. | Steel containing not more than 0.4 per cent | of carbon could be hardened perfectly by | quenching at a temperature of 750 degrees | C., if it had been heated slowly; while to} obtain similar results with rapid heating a} temperature of 810 degrees C. would have | to be reached. The point emphasized was that the steel should be heated until its mag- | netic properties disappeared. It was men- tioned that the electro-magnetic method of treating steels was applicable, with slight modifications, to a wide range of alloy steels. Products from Marine Animals.—At a meeting of the American Leather Chemists Association a rather interesting paper was | delivered on the products that are obtained from marine animals. The paper dealt par- ticularly with the products that are gained from sharks. It was said that in tropical water sharks that var¥ in size from two to | twenty feet are caught, the average size being ten feet. The most common method used for catching is by the use of gill nets. These are 300 yards long and 12 feet deep and are suspended in the water by buoys and anchors. The small fish are allowed to pass through the net while the large fish are re- tained. On pulling in the net a blow is de- livered by one of the men between the eyes of the shark. It is then hooked in the mouth and hauled on board. A good boat- load is 40 sharks, although 100 ean be han- dled. Skinning is done by eutting down the back and working the skin over the sides and belly, any adhering flesh being subsequently removed. The skin is now salted down, ready to be sent to the tannery. The liver ean now be used for oil recovery, as it con tains approximately 50 per cent of oil, which for some purposes might replace cod or men haden oil. The bulk of the flesh is used either as manure or poultry food. Pimento Seed Oil.—Pimento seed oil is a comparatively new product. The seeds con tain approximately from 18 to 19 per cent of oil, which corresponds to forty gallons of oil per ton of seed. It is dark red in color 2.3 per cent of free acids. and contains 2. Coloring Mente Fruits.—The Bureau of Chemistry has developed a process for This process is now being quite geneially employed in California. The use of ethylene displaces |entirely the old process of bleaching by means of coal-oil burners with or without special humidifying means. In the new method the ethylene is merely forced into the sweat room, and if the room is tight only about one ecubie foot of the gas will be needed twice daily for 5000 cubic feet of air space. If the “gassing” is done under can- |} vas, the quantity of ethylene employed is doubled. The coloring, depending on the} amount of green color in the fruit, is ac: | complished usually in two or three days, the | maximum being five days and the minimum | 1%, days. The proper temperature for or- | anges is from 70 to 75 degrees and for | lemons from 60 to 65 degrees. The “gassing” | has also been done by forcing the ethylene ey eee, hand as A TE NE ST RE RE SIG NAR RNE Bas t e ie eee ee ee Mn CS eee eh en Ue eee ae ee ee AMERICAN In Slow Moving Traffic —a Cool Motor No driving condition tends to overheat a — more quickly than the uncertain, top-and-start conditions of crowded boul- po and downtown streets. Few hills our 9 a motor more severely than dense traffic. How fortunate the driver whose car is Harrison-cooled! For no matter what the condition of roadway or traffic may be, he is confident that his motor will not overheat. The Harrison reputation has been built upon the superior performance of Harrison Radiators under the most try- ing motoring conditions. Motorists have come to know that for continuous and unfailing radiator per- formance, no worthy substitute has ever been devised for the original hexagon cell- ular core that forms the basis of Harrison efficiency. Accordingly, there is an unmistakable trend on the part of manufacturers of finer motor cars to provide Harrison Radiators as standard equipment. Harrison Radiator Corporation ae New York ARRISO) COOLED The Mark of Radiator Satisfaction Bt * 4.7 greet: ce 2 ts] ks ‘ i 2 § ha eG ew Hema” reuse t RANE EON SCI REO AE ORE RS ae Cait sctitienaseshieies sc mbas Te RABE,

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on this lew cost machine. making profits with 6"x20". Saws 2'6" stock. 1” wide x 1'9” . gnnding, and face-plate Motor 's to *4 h.p. Ma- aid as illustz:ated or without

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| pigment, by adding soaps, water, mineral oil into cars already loaded. Five cubic feet} per car per day has been found to do the work. The cost of the bleaching by this process runs from 34 cents to 80 cents per ear of fruit. This depends however, on the length of time consumed in the bleaching operation as well as on the number of gas applications per car. Paint Plasticity Factors.—The practi- eability of expressing quantitatively the ef- fects produced upon a paint by long grind- ing, by changing the concentration of the or deflocculating agents and the like is point- ed out by E. C. Bingham and A. C. Jaeques in Industrial and Engineering Chemistry. Since the yield value and mobility are inde- pendent properties, these factors affect now one of these properties, then the other, and sometimes both simultaneously. This inde- | pendence and the oceasionally prodigious magnitude of the effects enhance the impor- tance of the plasticity method. Comparative results of experiments are given. New Deposit of Soapstone in Austria. It is reported that an enormous deposit of soapstone has been discovered in Zwettl, not far from the Bohemian frontier. The soap- stone, which is stated to require very little preparation, can not only be eut, sawn, drilled and polished, but will absorb many colors, a property that should lead to its extensive use in powder form in the color industry. The deposit is the most important of its kind yet discovered in Central Europe. Liquid Oxygen as an _ Explosive.— Liquid oxygen explosives have been suecess fully used in Colorado by the Department of the Interior in experimental mine blasting and road construction work at a cost of ap-| proximately half that of the gelatin dyna-| mite required to do the same work. A liquid | oxygen explosive consists of carbon black, wood pulp or some other carbonaceous ma- terial made into eartridges and soaked in liquid oxygen. tonated similarly to ordinary dynamite with eap and fuse or with electrical detonators. Besides costing less, the liquid oxygen ex- plosive is said to be much safer to use than ordinary dynamite. There are disadvantages resulting from its use, however, and much is yet to be learned before it can be univer sally adopted in metal mining. Sulfuric Acid Manufacture —In Chemi- ker Zeitung, 1922, page 699 there is given a

This explosive ean be de

| short description of a new method of making sulfurie acid in which the chambers are re placed by horizontal eflinders provided with a number of perforated plates. This method is being worked on a practical scale in South Africa. The hot sulfurous acid gases first | pass through a Glover tower, where they are cooled down to about SO degrees C. and at the same time they increase the acid con- | tent of the irrigating acid liquors from 66] per cent to 7s per cent. Then the gases, mixed with water vapor, are made to enter the horizontal cylinders at the bottom, meet- | ing a downward current of nitrosyl sulfurie acid. Accordingly, the acid is freed from its nitrogen content while the sulfur dioxide is converted into sulfuric acid, with resulting outflowing acid. The evolved nitrogen oxide gases are again absorbed in two Gay-Lussae towers, connected in series and used further in the increased coneentration of the process, New German Motor Fuel.—A new German motor fuel, under the name of benzolite, has appeared on the market both in Germany and in England. This fuel is a patented product and consists of 50 per cent benzol, 20 per cent gas oil and 30 per eent of aleohol. It is said to be the sue cesser to a preparation known as “tetralit” which was a mixture of benzol and tetralin. The new fuel is a water-white liquid derived from naphthalene and is of about 0.975 specific gravity at 30 degrees C., flashing at 78 degrees C. and of high B. T. U. capacity. In practice it is mixed with an equal quan- tity of petrol or benzol. Oil Paint and Drug Reporter, November 12, 1923. Use of Water Glass in Paving Streets. —In the city of Locle, Switzerland, accord- ing to the Chemiker Zeitung, a macadamized road was built in which the sand that was} used in making the top surface of the road was first treated with a solution of water glass. About one hundred and twenty liters of ordinary water glass were used per cubic meter of sand. It is claimed that the road, made from material treated in this manner, | lasted three years. After the application of | the top surface the road was well rolled to} make it as smooth as possible. Very heavy | traffie passed over the road in the three} years that it was in use. It was found that |

| gen. |} look much like cement or May, 1924 the water glass had penetrated to a depth of ten centimeters and had cemented together the particles of sand and dirt into a firm, solid mass for the same depth. Glycerin as a Seal for Liquefied Hydro- One of the difficulties which the United States Bureau of Standards has en- countered in the liquefaction of hydrogen is the securing of hydrogen of sufficient purity. If other gases are present, they become frozen at a temperature higher than that at which hydrogen liquefies. This clogs ap the apparatus and stops the process. The stor- ing of hydrogen in any kind of a gas holder is therefore a matter of some difficulty be- cause gases are very apt to diffuse through the liquid seal used in the holder and become mixed with the hydrogen. Experiments were made during recent months on the relative rates of diffusion of nitrogen through glyc- erin, machine oil and water. It was found that the rate of diffusion through glycerin, is much lower than through water or ma- chine oil. This was to be expected because of the extremely low solubilities of nitrogen and other gases in glycerin. The Bureau now proposes to employ glycerin as a seal for the gas holder used for the temporary storage of pure hydrogen.

Plombit, an Acid Resistant Material.— This is the name given to a product that has recently appeared on the German market. The material is in the nature of an artificial asphalt which can be obtained in any desir able color and of higher melting point than is possessed by the ordinary run of asphaltic substances. The melting point of the plom bit substance is in the neighborhood of 130 It is made in a variety of colors and is completely odorless. According to the patent specifications it is a complicated com- bination of oleic acid with hard rubber plus the addition of concentrated sulfurie acid and free sulfur. The new product is of con- siderable interest to chemists for the sub stance is perfectly acid-proof, as it resists all sorts of acids in varying concentrations and is therefore well suited for lining the walls -anmd bottoms of acid tanks and con tainers of all sorts, and also for the protec tion of machinery that is subjected to acid The process of covering degrees C. vapors and fumes. the metal apparatus with the plombit plates These sheets which ceramic plates, are dipped into the molten plombit and ce mented together, so that an even surface, is somewhat as follows. free from cracks or openings of any sort 18 obtained. For further details see Chemiker Zeitung. Synthetic Marble.—A new process of manufacturing synthetic marble has been devised in which the marble is made by a wet method in place of the fire method. <A mixture is made of chloride of calcium and an aqueous solution of sodium carbonate or a mixture of precipitated carbonate of lime and sodium chloride solution is heated in autoclaves at a temperature of 300 degrees C. and 24 atmospheres pressure for a period of eight hours. A compact mass is obtained in this manner. The product resembles marble, has the same high lustre. When sodium sulphate is employed in admixture with chloride of calcium a product is ob tained which resembles alabaster.—Chemiker Zeitung, 1923.

Hexalin Soaps.—Hexalin and methyl- hexalin soaps are being made and used in Germany on a large scale for various textile and laundry purposes. The composition of some of these soaps is given below. This data was derived from the German period ical, called Seifenseider Zeitung. In the first formula the soap is made from a mixture of HOO parts of linseed oil, 250 to 300 parts of hexalin, 199 parts of potash lye of 50 de grees Be., and 1208 parts of water. Another formula eonsisted of 500 parts of rape oil fatty acid, 500 parts of hexalin, 195 parts of potash lye, 50 degrees Be., and 1705 parts of water. Still another formula consists of 200 parts of cocoanut fat, 130 parts of linseed oil, 200 parts of hexalin, 156 parts of potash lye and S880 parts of water. Products which re- semble soft soap are made from the following formulae: 500 parts of linseed oil, 300 parts of methylhexalin, 100 parts of caustic potash te., 140 parts of soda lye, 36 degrees Be., and 230 parts of water; 500 parts of linseed oil fatty acid, 300 parts of hexalin, 52 parts of potash lye, 250 parts of soda lye and 300 parts of water. These in- gredients are mixed together in a_ kettle heated with indirect steam until a clear solu- tion is obtained. The hydrogenated phenols, hexalin and methylhexalin, aid in the saponi- fication of the fats by the alkali so that the manufacturing process is shortened. lye, 50 degrees

K¢4!

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a) or) ou May, 1924 SCIENTIFIC AMERICAN WESTINGHOUSE ELECTRIC AY aa 7 — ai wy : 2 = 3 orf a Slt rl, =) "Ee 4 HEN Ya a wh MATERIALS HANDLING WITH ‘FEWER HANDS The same compact, powerful, easily controlled hoists ore from the mine, To Modernize~ Motor-driven machines the motor MOTORIZ E derricks, cranes, hoist- ing and conveying ap- paratus—load and unload anything from iron ore to live elephants, with equal ease. All products of factory, farm, mine and forest meet at the wharf where nations barter, as did individuals in the village market places five thousand years ago. machine grain into the elevator, every sort of material from one factory floor to another. It operates long moving platforms on which motor cars grow like magic, traveling cranes in steel mills, baggage trucks in railway stations. Whatever your materials handling problems, there is a solution in some form of motorization. WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY Offices in all Principal Cities Representatives Everywhere Westinghouse © 1924 by the Westinghouse Electric & Manufacturing Company

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366 JUST PUBLISHED Going to Build? if the answer is “Yes” or “Maybe,” then here is your book —the Scientific American’s Home Owners’ Hand-Book, just published and designed to give the A to Z in practical home building. The last word on the building conditions and methods of 1924. The book is an authoritative guide—as authoritative as Scientific American itself—on the subject of building, how to judge materials, how to plan the house according to loca- tion, building considerations, decoration inside and out. Also contains the legal aspect of water rights, sewers, etc., and in addition the many modern appliances and housewife luxuries, and how to install them in the building. 512 pages of the essentials in building that will turn the house you build into a home. If you are going to build, $2.50 is a slight insurance cost against faulty materials or serious mistakes in construction. Order your copy now—coupon will expedite. SCTENTIFICAMERICAN PUBLISHING CO. MUNN & CO. 233 Broadway, New York Book Department S. A. Scientific American Publishing Co., 233 Broadway, New York City Gentlemen: Please send me a copy of the Home Owners’ Hand-Book, inclosed find $2.65, charges prepaid. Name SERRE NOOR SOOT TEETER HERE E HEE HEHEHE EE EE EH ESS ES ES EE ES ES ES ES SEES ESOS ES OSES ED EES Address | | | bottom of the SCIENTIFIC AMERICAN The Story of Steel—V (Continued from page 310) the adjoining transformer house holders that grip the carbon electrodes. to the The electrodes is maintained with a clear spacing of about three-quarters of an inch between them and the surface of the slag. At the South Chicago Works, the electric furnace is used in conjunction with 25-ton Bessemer converters and large tilting basic open hearth furnaces of 200 tons capacity. The capacity of the electric furnace is 25 tons and the charge consists of all-blown molten Bessemer metal, or a charge of molten open- hearth metal from the 200-ton tilting furnaces is used instead of Bessemer metal. Three- phase current is used, and the amperage, automatically regulated, runs from 6000 to 14,000 per phase. The current comes in to the transformer house at transformed to 110 volts. If the furnace is producing .80 carbon steel, the temperature will rise to about 2750 degrees; if it is making .O8 carbon steel, the temperature will rise to 2850; and for certain will reach 3000 degrees Fahrenheit. It is needless to say that the perfect con- trol of the temperature at all times, during the process of refining, as well as of the chemical reactions, and the possibility of making many sample tests during the heat, are among the great advantages of electric refining. The sequence of operations in refining a charge of metal, is as follows. First: Twenty-five tons of blown molten Bessemer metal or open hearth metal is poured in. Second: The on. Third: 1400 pounds of lime, and if Bessemer metal be used, 900 pounds of iron oxide are added. This forms a slag for the removal of the phosphorus. Fourth: After the phosphorus has been reduced from .09 to .0O8 of 1 per cent, the preliminary or oxidizing slag is removed from the furnace, and a new slag is made by shovelling in 1100 pounds of burnt lime, 200 pounds of sand, 200) pounds of fluorspar and 200 pounds of coke dust—all for the purpose of deoxidizing the metal, and eliminating sulfur. electrical current is turned or other alloy is added to produce the alloy steel required. The treatment, as above | described, lasts about four and one-half} hours. | stresses put upon | much the same manner as if the disk were a | Finally, when the metal in the charge has been thoroughly refined, the proper amount of manganese, nickel, vanadium, chromium, In the next chapter of the series we shall | which | deal with the open-hearth system, by the bulk of the huge output of steel from our American mills is produced. Exploring Within the Steel (Continued from page 317) graphic record is being made, the record is a straight line. When, however, a discontinuity such as an inclusion, a crack, or a hard or soft spot passes through the solenoid a red light flashes or a bell is rung and the spot of light on the galvanometer moves sharply, while the photographie record is no longer a straight line but shows a hump. As applied to an elevator cable: supposing that a single wire has been broken, even if the break is inside the cable and is invisible to the eye, the defectoscope not only shows that there is a break but it shows exactly where it lies. This fact is especially valu- able in application to elevator or mine hoist | cables that have been in continued use. The solenoid can easily be installed around the cable, the control and recording device being located at any desirable place, whether quite remote or not. A highly interesting defectoscope is now nectady where it is used for testing the bucket wheels of large steam turbines. Some of these forgings are as large as ten feet in diameter and four inches in thickness. They must be of unquestioned integrity, for the them by revolving at a high rate of speed are extremely high. By beginning the defectoscopic analysis at the periphery of the disk and moving toward the center in a spiral the analysis is made in scale installation of the single long piece. Since this installation was made two years ago, perfect results have been given. It is | believed that no piece which has been re- |has ever turned out on | good disk, and no accepted disk has ever jected as a result of the magnetic analysis “autopsy” to be a 2200 volts, and is| products it} (reducing) | in regular use in. Sche-| May, 1924 Write For It! How to do 52 LATHE JOBS LATHE WORK is a valuable 8 - page bulletin contain- ing 52 instructive illustrations showing the Lathe in opera- tion on 52 prac- tical Lathe jobs that come up in general manufacturing and machine shop, showing the proper method of machining each job. CATALOGUE NO. 83 describes the entire line of South Bend Lathes and attachments. CHECK BOOKLETS DESIRED, ENCLOSE THIS AD WITH YOUR NAME AND AD- DRESS, OR SEND CARD. '| SOUTH BEND LATHE WORKS | 421 E. Madison Street South Bend, Ind. “WONDER” COLD PIPE, TUBING | AND BAR BENDERS Standard of the World Hand and Motor Operated 14 Sizes of Machines What it costs te bend pipe l-inch pipe -_ cts 2-inch pipe 10 cts 4-inch pipe 26 cts 6-inch pipe 60 cts 8-inch pipe $1.00 American Pipe Bending Machine Co. 32 Pearl Street, Boston, Mass. 4 INVENTIONS PERFECTED—MODELS MADB . Ina fully equipped machine shop Manufacture dies, tools, jigs, and fixtures of precision Let us manufacture and act as your factory 301 W. Grand Ave. p> Chicago, Ll. Tel, Sup. 1819 STEEL STAMPS METAL CHECKS STENCILS fren tarre] CALS AND FIcURES - SEND FOR ~ CATALOG THE SCHWERDTLE STAMP CO. BRIDGEPORT, CONN. Limited gratis fully teed stand- ard make ¢: Hive Da Days Free aes 00 Annually w eulde you step by can train at home poms, es o by: as eras and gre of te ne Cegree ce of to. con easy terme. e furnish call text ma oat Teche rolume’ Law fae Library, Gok Ge' Ca a. e 12). page i LaSalle Extension University, Dept. SSi-4 “Chicago Rapid Production on Small Work ly production in tool rooms, repair eae, ete. a for Sn prices. EY MACHINE. TOOL co. Experimental and Model Work Fine Insteuments and Fine Machinery, nventions Developed. Special Tools, Dies, Gear Cutting, Ete. | HENRY ZUHR, Inc. 489-93 Broome St., New York City Tired, Aching Muscles ! Enjoy a spring day at your favorite sport without suffering that disagreeable setback. Have Absorbine, Jr., in kit or locker. Apply it promptly. As if by 14” x6’ Price: $415. magic it prevents that stiff, lame PT feeling. You are fit as usual the + pe next At all druggists’, $1.25, or postpaid, Liberal trial bottle, we., postpaid W. F. YOUNG, Inc, Heats cxmeagen MA pro’ SCO] wou beet ten disk if dica the Hoy ing che! the 80 8 met som agre thei the was of ing had the erus a ec cau disk T ear geal ner com Ss Bes: tire! sion pho: eau: cial] rail Sut proc dan; rail high they of | Ir the whi rail chet shov inel it b inst pre ing Ir the but sco} A I dur a he mou mat enti plai “fla pre\ rail had ceal mov it v van inte one latt the eati the siti to ¢ ious tole T does exis the har of : pro] usil mag piec exa and pro) piec eal exp plac the noi con con) mel

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May, 1924 proved bad in service. Because of micro- scopic blowholes and other defects which would have remained unknown had it not been for the use of magnetic analysis from ten to twenty per cent of these expensive disks have regularly been thrown out. In one case this particular instrument in- dicated a bad spot that seemed to be about the general size and shape of a cigar box. However, since the steel from which the forg- ing had been made had a very satisfactory chemical analysis, but for magnetic analysis the disk would have been accepted. In fact, so sure were the proponents of the magnetic method that there was large inclusion of some sort in the large forging that they agreed to repay the cost of the forging if their belief proved inaccurate. Therefore, the disk was cut open. The suspected area was found to contain the fragmented pieces of a broken brick! This brick, as illustrat- ing the total depravity of inanimate things, had managed to get into the blooms during the rerolling of the ingot and had been erushed. The pieces were distributed over a considerable area, providing the potential cause for a céntrifugal explosion had the disk been used in a turbine. The testing of large circular specimens like ear wheels, locomotive tires, fly wheels, large gears and elevator sheaves in a similar man- ner to that of the turbine disks has also been commercialized. Steel rails were formerly made by the Sessemer process, but it was impossible en- tirely to eliminate the danger of an oceca- sional batch running a little too high in phosphorus. This element has the effect of eausing “cold shortness,” or brittleness, espe- cially in cold weather, and many disastrous railway wrecks have resulted from this fact.

But rails are now made by the open hearth process and are practically free from this danger. They cost more to make, but the railroad companies do not hesitate to pay a higher price for them, in fact for two decades they have voluntarily paid a bonus for rails | of high standard. In one ease a serious wreck was caused by the accidental inclusion of a common bolt which had got into the molten metal in the| which rail mill and due to some cause a chemical analysis would have probably shown, had failed to dissolve in it. This included bolt had weakened the rail until it broke at the critical moment. A simple installation of the defectoscope would have prevented that particular rail from ever leav- ing the mill. In the Burrows laboratory in Jersey City the writer witnessed one particularly simple but significant demonstration of the defecto- scope’s ability to “spot” defects in steel rails. A rail that had been in a railway during a period of some years was placed in a horizontal position, and a defectoscope was use on mounted on a movable carriage in such a manner that it was able to traverse the entire length of the rail. First it was ex- artificial plained that a_ well-camouflaged “flaw” consisting simply of a small hole had previously been drilled into the webb of the rail at some point along its length. This| had been filled with putty and the job con- cealed with pigments. As the _ solenoid moved slowly ‘along the length of the rail it was observed that the beam of the gal- vanometer swung slightly at definite equal | intervals of about eighteen inches. Then, at | one point it swung quite sharply left. The | latter phenomenon had accurately located | the hole, while the former stood as an indi- | cation of the strains that had been put upon the steel at the cross ties. As the defectoscope must not be too sen- sitive for commercial use, and must be able | to distinguish between insignificant and ser- | ious flaws, it can be adjusted to any desired | tolerance in this respect. The magnetoscope unlike the defectoscope does not always give an indication of the existence of flaws. It is used for checking the general physical properties such as hardness, grain size, chemical composition of a piece of steel or iron against the like | properties of a standard piece. For example, using one of the types of magnetoscope, the magnetic comparator, suppose a_ certain piece of material is known to possess the exact properties wanted for making a tool and it desired to know whether these properties have been duplicated in other pieces of material. eal solenoids each having its own system of exploring coils, are provided. In one is placed the standard material; in the other, the material to be checked. The two sole- is noids, energized by alternating current, are | connected in series and the test coils are connected in opposition. mens are not identical in their magnetic In this case two identi- | If the two speci-| SCIENTIFIC properties a differential effect will be mea- sured on an indicating device. This is be- cause the voltages set up in the respective | test coils are different. The standard piece may be of any con-| venient length, while the piece to be tested | may be in a continuous length and may be} drawn through its coils at any desired speed | up to 200 feet per minute. The deflections | on the indicating device may be read by means of a lamp and seale, or they may be made to close the contacts of a delicate relay | so that signal lights and bells, or a marking device may be energized, | Examination of small circular pieces such as balls, ball races, rollers, and piston rings by means of the magnetoscope makes the location of cracks, flaws and segregations easy. In addition, variations of quenching temperatures of as low as 10 degrees are detectable. This method has just been| adopted for testing the bevel gear rings of a well-known make of motor car. Drills, for instance, which have received proper heat treatment are readily separated | from imperfect drills, and laminated regions | in plates can also be determined by means of one form of the magnetoscope. The application of magnetic analysis to irregular shapes must be considered indi- vidually, for while the detection of flaws is| usually possible, it is not always necessary when the raw stock has been certified mag- netically. The item of greatest interest in semi-finished parts is the correctness of the heat treatment, and it is in the sorting out of properly heat treated articles that the application of magnetie analysis to irregu- lar parts and small shapes finds its widest usefulness. Magnetic analysis is also applicable to the study of growing fatigue strains in steel under stress while in service. These strains | bring about a change in the magnetie quali- ties of the steel. For example, during the life test of a new model automobile, airplane or

other machine the model may be disas- sembled and the parts examined magnetic- | ally, permitting the detection of defective parts before the defect has otherwise made itself discoverable. In short, practically three-quarters of the steel products the world are potential subjects of magnetic analysis, and when they have become actual subjects the factor of | safety allowed in most steel construction work will according to the proponents of the method, be materially decreased, while the losses due to mysterious failures will greatly diminish. of Post-Treaty Standing of the World’s Navies (Continued from page 320) ment we also show a large predominance, with 93 ships. In fleet submarines of 1000 tons and over, however, we make but a poor showing, Japan has 24 ships in this class against our six, the eight possessed by Great Britain, and nine by France. Our position strong in aircraft carriers; and this is due to our conversion of two of our huge battlecruisers, 876 feet in length and with a designed speed of 33 knots, into aircraft | carriers. Japan should have come next with | three ships in which two battlecruisers were to have been included. One of these, how- ever, was injured in the earthquake and a battleship has been converted in its place. We have drawn up this comparison with a | view to placing before Congress and the coun- try the urgent need for the construction of at least eight or ten light cruisers of the 8000 to 10,000-tons class. The conference per- mits the arming of such vessels with guns up to eight-inch caliber, and a squadron of 10,000 ton, 32-knot vessels, carrying eight of is

| these weapons, and with a steaming radius that would enable them to cruise anywhere on the main sea routes of the world, together with the construction of a dozen flotilla | leaders, would go far to correct the present | want of balance in our fleet. Making High-Tension Cables (Continued from page 325) front through a die somewhat larger than its own diameter, the difference being usually about 1/4 or 9/32 inches. As the eable passes through this chamber a pressure of | 500 pounds per square inch is exerted on the | plastic lead by the hydraulically operated | piston. This pressure forces out an envel- ope of lead around the paper cable as it passes through the die. The reason for hav- ing the lead plastic instead of molten is two- | fold. First, because it must not be hot enough to damage the paper or compound and second, because if fluid it would squirt AMERICAN

chart in business.” truck “face to face.” It’s a revelation ! of your problem.

DATE ¥i43__— 3 Hicka CAR No_.3__ DRIVER A—Got started late from garage. B—Nothing to do till 9:30. C—1 hour and 20 minutes “‘static.” D—Lunch, and settling the world war. E—Standing, at $3.00 per hour. F—Ditto. G—Reports at 5:30, earns overtime. H—Truck used at night. The Real Diary of a Real Truck No wonder it has been called “the most interesting For the first time you are enabled to see your own And you notice at once that your driver is only a part Now you see your whole problem laid out before you —analyzed for you in terms of hours and minutes. Write for Booklet S The Service Recorder Company Cleveland, Ohio Why?

i The Advice of Specialists —Yours for the Askin3 I tal the friendly desire to co-operate with in- ventors and builders of small motor driven tools, novelties or appliances, we maintain our Engi- neering Department—a corp of specialists whose chief duty is to devise ways and means of apply- ing fractional horse power motors to new uses. If you are developing a new product and are perplexed with the problem of finding a motor exactly suited to your needs, we want you to tell our Engineering Department of your difficulties. Years of close contact with the uses and applica- tion of small motors—extensive experience in counseling with other inventors and manufac- turers, has given the personnel of this depart- ment a specialized knowledge that will be ex- tremely helpful to you in the solving of your problem. Feel free to ask these experts for advice. They’ll be glad to do everything possible to help y ou find aspeedy solution to your power unit difficulties and will give frank and im- partialopinions on any motor question. Fill in and mail the DUMORE Survey Blank, attaching rough sketch or blue print of your product. WISCONSIN ELECTRIC COMPANY 4800 Sixteenth Street, Racine, Wisconsin Dumore Fractional HPMotors |

WP ------------ DUMORE | | Survey Blank | Fill in and Mail | | Wisconsin Electric Co 4800 Sixteenth St., Racine, Wis. { Weare interested in small motors and | desire to receive, Gratis, the recommenda- | tion of your Engineering Dept. as to what " motor can best be applied as a power unit | for the tool, appliance or novelty mentioned below: | Motor will be used for (State purpose) (a We will supply you with sample of | machine for test purposes ( Yes or No) (b) We will need (c) H. P. Motor | (d) For constant or intermittent j service. ' (e) Motor will or will not be enclosed in machine. (f) Wewill require R. P. M, (State speed). | (g) Constant or variable speed. i | | l | | | | -_ <9 ! a ; © ; H m E i ; H g i % ‘ i = Soe 2s i & ; © ~ © & & S22 449 4-3 ge <£ O ® & & |

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368 SCIENTIFIC AMERICAN LG When we ‘say to you that the Shaving Stick has important ad- vantages over shaving preparations in any other form, we can do so without bias, for we manufacture shaving sticks, powder and cream. In its attractive nickel box, our COLGATE & CO. y having Stick “HANDY GRIP"AND REFILL For Comfort, Convenience and Economy The famous “Handy Grip”, with a trial-size shaving stick in nickel box, sent for 10c. When the trial stick is gone, buy Colgate “Refills” for the price of the soap alone, 25c. Established 1806 7 ATES bi, | | “Handy Grip” Shaving Stick is most convenient for traveling. It will not crush when packed, and it makes a wonderful lather for easy shaving. It is not uncommon for a Colgate Shaving Stick to last more than a year in daily use. NEW YORK Personal Stationery! 200 SHEETS and $7.00 100 ENVELOPES Printed With Your Name and Address *, with envelopes to match printed in beautiful, rich and envelopes, and sent $1.00. (West of Denver 1.10.) inconvenient to D. to you and outside postpaix of U. If send the money, we will ship C. O ) Write name and address plainly. | Money returned you are not more than sat-| isfied Order today! ELITE STATIONERY COMPANY 5074 Main Street Smethport, Pa. WANT WORK uiih HOME . Farn $18 to @) a week RETOUCHING photos. Menor women. Noselling or canvassing. We teach you, guaran | tee employment and furnish WORKING OUTFIT FREE. | Limited offer. W rite teday. “CRAPT TU DIE | 8000 Sheridan Road ‘1 ST . Chicago | The MONARCH Jr. Lathe Ideal for Beginners or Experts The MONARCH Jr. 9” Engine Lathe (illustrated) is simple and trouble proof—beginners soon turn out finished work—the choice of experts too. A splendid lathe for inventors, mechanics, small shop owners. completely equipped ; accurate; semi quick change gear, auto safety devices. $270 9” 2% ft. bed— with bench legs Also built with bed lengths up to 5 feet. Made in 11-inch swing size too, at slightly higher price. THE MONARCH MACHINE TOOL CO. 430 Oak Street SIDNEY, Ohio Compact; ness. SCIENTIFIC AMERICAN PUB. CO. Book Shelf Clearing To clear our shelves we are offering a number of books, many at attractive discounts and all standard works of reference and useful- Write for list of titles and prices. additional details and invite inquiry. We shall be glad to give 233 Broadway, New York | fectly manufactured product, for with high | tension out all over the place and would not form} evenly around the cable, or hold its shape. | Cables, any more than any other kind of electrical apparatus, cannot be delivered | without first being tested to make sure that | they will give the service for which they! were designed. In service they must often | undergo a considerable amount of bending | during the process of installation, they must be able to withstand voltages a good deal in excess of the operating voltage, on account of momentary surges, and all the other elec- | trical characteristics already touched upon must be checked up. That means that bend- ing tests, as well as voltage, conductor resis- tance, insulation resistance, and dielectric loss tests must be made. There are some points about the voltage test which illustrate particularly well how} earefully the design of high tension cables has been studied, and necessarily so. The} duration of excessively high voltage is of im- portance as it has been found that an in- sulating material may withstand a very high voltage momentarily but will fail if it is sustained for several minutes. It is also a fact that the kind of voltage has a direct | bearing on the strength of the insulating ma- | terial. That is, insulation such as impreg- nated paper can withstand something like two and a half times the voltage with high | tension direct current that it can with 60- cycle alternating current, but with high fre- quency or oscillating voltage, such as from condenser discharges, it fails at about half | that voltage. Thus in testing care must be| taken not to damage the cable by using the wrong kind of voltage, or in operating under service conditions to permit the production of surges, very likely of high frequency, by improper switching methods or otherwise. So it will be seen that it is not a simple matter to convert old ropes and oil refinery refuse into a scientifically designed and per eables, where the forces to be con trolled are so powerful that they will most certainly search out the slightest weakness, | nothing short of perfection will suffice. Truffles and Truffle Hunters (Continued from page 332) from the common truffles of Europe that they are placed by botanists in a distinct | family. The first truffles known to the French | sporum, were the white summer species, 7'uber aesti vum, and the Bourgogne truffle, Tuber un cinatum. The former soon came to be known as the “English truffle,” since it was one of the commonest species in the London mar- kets, being found from midsummer to au- tumn in beech,:oak, and birch woods. It is about as large as a small apple and is covered with conspicuous black warts, while the flesh is brownish with white veins. The odor very strong and penetrating and the flavor agreeable. That queen of all the truffles, the Périgord, or Tuber melanosporum, was not discovered until about the end of the fifteenth century. | At the present time, when the “French truffle” is spoken of, this is the kind that is meant. Périgord pie, more commonly known as Pdté de foies gras, is flavored with | this species, which is famous for its delicate aroma, its uniformly good quality, and its regular shape. It about the size of a walnut, rounded in shape, brown or black externally and ornamented with coarse warts, is iS while the interior is blackish-gray varie- gated with white veins. The odor is very pleasant, resembling that of a strawberry when the tubers are young and becoming powerful with age. It oceurs during the autumn and winter months under oaks and beeches, the live-oak being its favorite shel- ter-tree. The “Italian truffle,’ 7. magnatum, has a strong odor resembling that of garlie or decaying It is quite irregular or lobed in shape, without warts, yellowish or brownish-yellow externally and _ pale-liver colored veined with white within. Although usually the size of a walnut, it sometimes weighs much ten or twelve pounds It oceurs in late autumn in clayey soil under willows, poplars, or oaks, and rarely in cultivated fields. Unfortunately, its flavor does not equal its odor in strength. Another onion-scented species, 7’. macro- is sometimes found in England be-| neath oak, beech, and willow trees. One of the characteristic winter species | is Tuber brumale, which is round and black, with sharp warts and the usual variegated flesh. Its odor is very strong and lasting. The “white truffle,” 7. album, oceurs in| England, Germany, and southern Sweden, cheese. as as growing half above the ground and half bur- | dance, May, 1924 ied. It is about the size of a large walnut and has a whitish-red tint. In the market at Trent, Italy, where I have made careful observations of the edi- ble fungi, the following species are usually found: Tuber aestivum, Tuber brumale, Tuber mesentericum, Tuber melanosporum, and Tuber uncinatum. In France, several million dollars’ worth of truffles are mark- eted annually at from one to two dollars a pound, many of which find their way to America. In 1913, nearly half a million pounds were exported from France to other countries. One October day not many years ago, some truffles were sent te our herbarium that were collected under oaks in the suburbs of New York City, with the aid of a dog trained in Italy. Two gentlemen had conceived the idea of developing our native truffles and raising dogs to supply the needs of those who wished to hunt them. The idea was a good one—scientifieally if not com- mercially—and we encouraged it. The dog was taken to an adjoining state and found other specimens, which were also sent to us. Three species of truffles had previously been reported from the eastern United States, but the records were scanty and the specimens few. Here were the actual fresh specimens; not many, to be sure, but still in sufficient quantity for scientific investi- gation. Anyone now finding this species can readily recognize it from the description or by comparison with the preserved types. This new species, as published by Miss Gilkey, is yellowish-brown, sometimes fur- rowed, without warts, one-half inch in diam- eter, yellowish within, marked with white veins. The sacs contain from one to four spores, which are large, yellow, and beauti- fully seulptured. It in New York, New Jersey, and probably in other eastern states, The possibility of finding native truffles occurs | of commercial importance in this country is rather remote, since they would almost cer- tainly have been discovered already by the French people of the South or the Italians of the North. However, there are sections in Virginia and the Carolinas settled by peo- ple who probably never saw truffles and it might be well to institute a careful research in those States and in regions lying to the west of them. If truffles exist there in abun- the hogs certainly know it by this time, since it customary to turn these animals loose in the forests and let them make their own living by hunting acorns and chestnuts and digging up poke-root. The introduction and cultivation of com- mercial species would seem perfectly feasi- 18 ble on theoretical grounds, since all the necessary facts and conditions now appear to be known; but careful experimentation alone would determine the accuracy of this conclusion. The following conditions would be essential. The soil must be light, shaded, properly drained, rich in decaying matter, and con- taining a certain proportion of lime and clay. Sandy soils are too dry and too poor to grow truffles, even if lime were added to them. The climate conditions of France and Italy furnish a criterion. New York is too cold for the best winter species, although some truffles found in northern Europe might grow here. Southern California is probably too dry, but farther north on the Pacifie coast there is plenty of rain, as well as moderate temperatures. The limestone regions of Virginia and southward would seem to be ideal localities, The best shelter-trecs of Europe are prob- ably the truffle oak, the evergreen oak, and the hazel. These and other European spe- cies might be planted in this country in places where they would do well; or a num- ber of our native trees and shrubs, such as oaks, beeches, hazelnuts, birches, elms, pop- lars and willows, might be used experimen- tally. The spawning method most largely used in France for establishing new truffle grounds is to take soil from truffle beds and spread it over the new ground. Another method, ealled colonizing, is to plant mature truffles just as one would plant potatoes, but with- out the same assurance of success. If there |is any virtue in the new method of making artificial cultures on leaves, it would soon appear in a new country where true truffles did not exist. In the case of the ordinary mushroom, excellent spawn may be grown from the flesh of the cap, without using the spores at all. These and other methods might be tried in several well-selected local- ities in the United States, which, in the event of success, would serve as centers of distribution of the spawn. 4