Science TechnologyEast India Company rule
Great Trigonometrical Survey begins at Madras
Measuring a baseline close to Madras, William Lambton set the Great Trigonometrical Survey of India in motion.
On 10 April 1802 surveyors measured a baseline on the level ground around St. Thomas Mount, near Madras, and with it the Great Trigonometrical Survey of India got under way. In charge was William Lambton, an infantry officer serving the East India Company. Triangles were then extended outward from this line, first over South India and in time across the entire subcontinent. Reliable maps of the Madras Presidency, and of India as a whole, rested on the groundwork the survey provided.
