Great Trigonometric Survey of India

The Great Trigonometrical Survey was a project which aimed to measure the entire Indian subcontinent with scientific precision. It was begun in 1802 by the infantry officer William Lambton, under the auspices of the East India Company. Under the leadership of his successor, George Everest, the project was made a responsibility of the Survey of India. Everest was succeeded by Andrew Scott Waugh and after 1861 the project was led by James Walker, who saw the first completion of it in 1871.

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. The Survey had an enormous scientific impact as well, being responsible for one of the first accurate measurements of a section of an arc of longitude, and for measurements of the geodesic anomaly which led to the development of the theories of isostasy.

From its inception in 1600 to the beginning of the nineteenth century, the British East India Company gained more territory on the Indian subcontinent. With the acquisition of new territory, it employed several explorers and cartographers to provide maps and other information on its territories, most notably James Rennell, from 1767 in Bengal. As Rennell proceeded making maps, some serious flaws in them surfaced, based on a lack of precise measurements. In 1800, shortly after the English victory over Tipu Sultan, William Lambton, an infantry soldier with experience in surveying proposed to remedy precisely that, through a series of triangulations initially through the newly acquired territory of Mysore and eventually across the entire subcontinent.

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