Mapping India: How Madras pioneered a new age of surveys and maps

During the 19th Century, this city that is now Chennai led India into a new age of mapping. Mark Madras week with us, exploring relics and stories of the Great Trigonometrical Survey

Back when explorers of the Western world were still finding their way around our land, penning India down as a map was no mean feat. The process, taken up by many through the centuries, was as challenging as it was historically, economically and politically important — and a major portion of it began right here in Madras.

The city has played a pivotal role in helping the world better understand the Indian subcontinent. The State’s history of cartography and surveying pushed the boundaries of its time, with academics attributing ‘India’s first modern scientific survey’ to the instructions of a Superintendent of Madras in 1787. Other than its own efforts in these fields, Madras has also contributed immensely to others’ efforts in surveying and mapping. Historically, it has done this through its involvement with the Great Trigonometrical Survey (GTS) of India, a pioneering survey utilising the method of triangulation.

“You had a map of a very large landmass of the world. It had been surveyed as far as its elevation and relief features were concerned. We shouldn’t forget that it began in Madras and eventually went all the way to Mt. Everest. It was an excellent survey. By the end of it, they [the British] knew the country like the back of their hand,” says historian and heritage activist V Sriram about the GTS that took nearly a century to be accomplished.

The GTS’ history can be traced back to the early 1800s in modern-day Karnataka. Following the defeat of Tipu Sultan in the Fourth Anglo-Mysore War, the British East India Company had control over vast amounts of the Indian subcontinent yet had little knowledge of its actual size and boundaries. When trying to solve this problem through surveys and exploration another problem arose: the lack of precise measurement for surveying. This was soon rectified by William Lambton.

Lambton, a soldier in the Fourth Anglo-Mysore War, had initially attempted to determine the breadth of the peninsula, from Madras to its opposite coast, and fix the latitudes and longitudes of many important places. After having received better instruments, and rejecting his initial attempt in 1800, he began a journey he would never end up seeing finished: the Great Trigonometrical Survey of India. 

On 10 April, 1802, this survey commenced with the measurement of a baseline near Saint Thomas’ Mount, Madras. From this a series of triangles was carried, about 85 miles East, North and South to Cuddalore covering over 3,700 square miles.

Sriram speaks on the cultural reasons behind choosing Madras: “Madras was really where the empire had begun. This was a very well established station as far as they were concerned, in 1802. It was also a question of where the army was located. With them being located in Calcutta, Bombay and Madras. The Survey of India, not yet named as such then, had its origins here [in Madras] as well”