History: The Great Trigonometrical Survey

Tim Middleton explores how India was mapped and the world’s tallest mountain named.

It was July 1819 and the monsoon was due. Lieutenant George Everest was in the middle of the Indian jungle between the Godavari and Kristna rivers with a team of 150 men. These jungles were home to numerous menacing creatures: hump-backed boars and tigers patrolled the forest floor; boa constrictors and bird-sized spiders lived in the trees; and hornbills ruled the air.

Then the monsoon struck. Vegetation sprouted from every crevice in the cracked earth and paths soon became choked with plants. Insects swarmed everywhere. Dry riverbeds became raging torrents.

Suddenly, Everest found himself cut off from his supplies by the river Musi, a tributary of the Kristna. His next goal, the hill of Sarangapalle, was the other side of the Kristna itself. Everest’s elephants, carriers of his prized surveying instruments, refused to cross the swollen river. So Everest and 12 of his trusty men took to the water in a coracle, a small round boat woven from palms and covered in animal hides, which he had found on the river bank. Evening was drawing in, but they pressed on to Sarangapalle, a further 12 miles. By the time they reached the hills the heavens had opened. They spent the night in a raging thunderstorm with no food or tents, their Harris tweeds doing little to keep out the rain. Within a few weeks, the whole of Everest’s party had succumbed to fever. Such was the life of a surveyor in India.

George Everest had taken leadership of The Great Trigonometrical Survey in 1823 upon the death of his successor, Colonel William Lambton, who established it in 1802. It was one of a number of surveys that were set up as part of the colonial enterprise; a way for the British to stamp their authority on Indian territories. It was essential for the British rulers “to have a complete geographical knowledge of the country for their revenue and administrative purposes”. The job of this survey was, quite simply, to determine where places were. Up until this time the only known method for locating a point on the Earth’s surface was to make astronomical observations, which took months if not years to complete. Lambton recognised that surveying by triangulation was the only sensible way to make a map of India.

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Image:
CIRCA 1840: Colonel Sir George Everest (1790 -1866) Welsh surveyor, geographer and Surveyor-General of India from 1830 to 1843.
(Photo by Time & Life Pictures/Getty Images)