The
Great Trigonometrical Survey was a project carried out by the
Survey of India throughout most of the 19th century. It was piloted in its initial stages by
William Lambton, and later by
George Everest. 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.