Magnetism
Free to read here, from Project Gutenberg.
Bibliographical history of electricity & magnetism, chronologically arranged
On the magnet, magnetick bodies also, and on the great magnet the earth
Electricity and Magnetism
The Letter of Petrus Peregrinus on the Magnet, A.D. 1269
The Study of Elementary Electricity and Magnetism by Experiment
William Gilbert, and Terrestial Magnetism in the Time of Queen Elizabeth
The Natural Philosophy of William Gilbert and His Predecessors