Context The
East India Company, and later the
British Empire, sought to form trade relations with Tibet. Additionally, exploration of Central Asia and Tibet were of particular interest during the
Great Trigonometric Survey of India because their geography was largely unknown to the British. However,
Qing China closed Tibet's borders after gaining significant control over Tibet's internal politics following the 1791
Sino-Nepalese War. A number of Europeans tried to reach Lhasa from India over the next hundred years; however, few successfully reached it, and local officials turned back most attempts at entry. A British attempt to reach Tibet from the east by travelling up the
Yangtse River failed in 1861, and
Edmund Smyth's attempts to enter Tibet from the west between 1861 and 1863 all failed as well. Because of the Great Trigonometrical Survey's past success with native surveyors,
Thomas Montgomerie (the astronomical assistant of the survey), proposed that native explorers be recruited to explore Central Asia and Tibet. Montgomerie's plan was approved in 1862, and his first recruits were
Abdul Hamid for an expedition to
Yarkand, followed by Nain Singh and his cousin Mani Singh for an expedition to Lhasa.
Recruitment and training In an 1861 letter, Smyth recommended Singh as a possible surveyor to Walker. Walker travelled to meet with Singh and recruit him and his cousin Mani. The two were sent to
Dehradun, the Survey's headquarters, and placed under Montgomerie's command. The two would spend two years training for their expeditions, learning a number of surveying techniques. Because the survey needed to be clandestine, a number of techniques were developed to hide the surveying. Mercury for thermometers was hidden in the bottom of a bowl, notes were stored inside a
prayer wheel, and survey gear was hidden inside the luggage. A
string of prayer beads, which usually had 108 beads, was modified to only have 100 beads; the pundits were trained to move one bead every hundred paces to count their steps. They were also trained to have a precise stride length of 33 inches across varying terrain.
First expedition Singh's first expedition began in 1865. He and Mani separated during the survey, with Mani travelling through western Tibet and Nain walking to Lhasa. Nain Singh reached Lhasa on 10 January 1866. He spent some time in Lhasa as a teacher of accounts before returning to India. During this expedition, Nain Singh estimated the altitude of Lhasa as 3,420 meters by boiling water; this was close to the actual value of 3,540 meters. He also estimated the position of Lhasa with celestial observations.
Second expedition Singh's second expedition explored western Tibet in 1867. Nain and Mani were accompanied by Kalian Singh, Nain's brother, and the three disguised themselves as
Bashahri traders. The expedition reached the goldfield at
Thok Jalung, mapped the
Sutlej river, performed an 850-mile-long route survey, and verified the position of
Gartok.
Third expedition Singh's third and final expedition returned to Lhasa via a more northern route than his first expedition and ran from 1873 to 1875.
Surveys During his secret survey of Tibet, Nain Singh was the first non-Tibetan to visit many legendary areas of Tibet, including the
Thok Jalung goldfields on 26 August 1867. He would later say that Thok Jalung was the coldest place he had ever visited. Nain Singh was a cousin of
Kishen Singh, another famous pundit explorer. ==Legacy==