# 1922 Index of Great Trigonometrical Survey of India

- By: Survey of India, Government of India
- Date: 1922
- Classification: Photograph
- Credit line: Report of the Survey of India for 1921–22
- Museum: [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:1922_Index_of_Great_Trigonometrical_Survey_of_India.jpg)
- Rights: Public domain
- Picture: https://invisiblenetwork.ai/thumbs/commons/thumb/6/64/1922_Index_of_Great_Trigonometrical_Survey_of_India.jpg/1920px-1922_Index_of_Great_Trigonometrical_Survey_of_India.jpg
- Who can see it: Teens profiles and older (museums give no ratings; placed by Invisible Network from the museum's own words)

Index to the Great Trigonometrical Survey of India (1922). India is shown on a 1-degree grid of green lines. The blue triangles indicate the Great Trigonometrical w:triangulation measurements. Triangulation series are indicated by a number in parentheses. These series are described in the table at the bottom left. The red dash-dot lines are telegraph longitude area.

Among the many accomplishments of the Survey were the demarcation of the British territories in India and the measurement of the height of the Himalayan giants: Everest, K2, and Kanchenjunga.