Great Trigonometrical Survey (GTS) Towers

A compilation of GTS Towers of West Bengal

The Great Trigonometrical Survey (GTS), started in 1800 and continued over half a century. It is often hailed as one of the most stupendous work in the history of science. The Great Arc (78⁰ E Longitude) was the backbone of the survey and the 1600 miles of inch perfect survey was the longest measurement of earth surface ever to have been attempted.

Collage of GTS Towers
Left – right: Paikpara, Akanpur, Bhalki, Bhola and Sukchar

Willam Lambton, an endearing genius, conceived the idea; George Everest, an impossible martinet, took it forward. The half a century long project involved equations more complex than any in the pre – computer age. It was also the most perilous project of its time, killing more men than any contemporary wars. Malaria wiped out whole survey parties, tiger and scorpions took their toll.