According to Peter Hopkirk in The Great Game (OUP, Oxford, 1991), “The concept of employing native explorers for covert surveys in lawless territories beyond India’s frontiers arose due to the Viceroy’s strict prohibition on British officers entering those regions. Consequently, the Survey of India, responsible for creating maps of the entire subcontinent and adjacent areas, faced significant challenges in mapping northern Afghanistan, Turkestan, and Tibet. A young officer in the Survey, Captain Thomas Montgomerie of the Royal Engineers, proposed a solution. He suggested sending native explorers trained in secret surveying techniques into these off-limits areas. Their chances of detection would be much lower than those of a European, even in disguise. Additionally, if they were discovered, the political fallout would be less severe than if a British officer were caught mapping in such sensitive and perilous regions.
“Surprisingly, given the British and Indian governments’ desire to avoid entanglement in Central Asia, Montgomerie’s audacious plan received approval. Over the next few years, several Indian explorers, including Nain Singh and Kishen Singh, were sent across the frontier in secrecy. They were hillmen, selected for their remarkable intelligence and resourcefulness. The term ‘pundit,’ which typically denotes a learned man, became the common name for them. The risk of discovery could mean instant death, necessitating utmost secrecy about their missions. Even within the Survey of India, they were identified only by a number or code name. Montgomerie personally trained them at Dehra Dun, the Survey’s headquarters in the Himalayan foothills.
“Montgomerie rigorously trained his men to take a consistent pace of known length—33 inches for Nain Singh—which remained accurate regardless of terrain. He also taught them methods for discreetly counting the number of paces taken during a day’s march, allowing them to measure vast distances with impressive precision and without arousing suspicion. They often posed as Buddhist pilgrims, who frequently traversed the passes to reach the holy sites along the ancient Silk Road. Each Buddhist carried a rosary of 108 beads to count prayers and a prayer wheel that they spun as they walked. Montgomerie cleverly adapted these items for their needs. He removed eight beads from the rosary, keeping the total at 100, which was mathematically convenient. At every hundredth pace, the Pundit would slip one bead from the modified rosary, meaning each complete circuit represented 10,000 paces—equivalent to five miles for Nain Singh.
“The day’s march totals, along with any discreet observations, had to be recorded in a secure manner. The prayer wheel, with its copper cylinder, served this purpose well. Instead of the usual prayer scroll, it contained a roll of blank paper that could be accessed by releasing a hidden catch. Some of these prayer wheels remain preserved in the Indian State Archives. Another challenge was the compass, as the Pundits needed to take regular bearings on their journeys. Montgomerie concealed the compass in the prayer wheel’s lid. Thermometers for altitude calculations were hidden in the tops of the pilgrims’ staffs. Mercury, used for setting an artificial horizon during sextant readings, was stored in sealed cowrie shells and poured into a begging bowl when needed. Concealed pockets were added to their clothing, and false bottoms were built into the chest carriers of most native travelers to hide sextants. All this preparation took place in the Survey of India’s workshops in Dehra Dun under Montgomerie’s supervision.
“The Pundits were also thoroughly trained in disguise and the use of cover stories. Their safety in lawless lands depended on how convincingly they could portray themselves as holy men, pilgrims, or Himalayan traders. Their disguises had to withstand scrutiny during months of travel, often in close quarters with genuine pilgrims and traders. Some undertook journeys lasting years. One became the first Asiatic to receive the Royal Geographical Society’s gold medal for contributing a remarkable amount of knowledge to the map of Asia. At least two of them never returned, while another was sold into slavery but eventually escaped. Collectively, their covert expeditions provided a wealth of geographical intelligence over two decades, which Montgomerie and fellow cartographers at Dehra Dun used to update British maps of Central Asia.
“In Trespassers on the Roof of the World, Hopkirk recounts some of these journeys, particularly that of Nain Singh. He initially traveled with his cousin, Mani, but they separated to reduce the risk of detection.
“They calibrated their instruments in the town of Bareilly, whose position was well-known to the Survey authorities, before successfully crossing into Nepal. Nain Singh managed to join a Ladakhi caravan bound for Lhasa. However, at one point, the Ladakhi traders switched to coracles and transported their goods and themselves 85 miles down the River Tsangpo (Brahmaputra) to Shigatse, Tibet’s second-largest town. Nain Singh, however, had to continue on foot, the reason for which remains unknown, ensuring there was no gap in the covert route survey he had been conducting since leaving Bareilly—without any of his companions suspecting his true intentions.
“[In January 1866] Exactly a year after departing Dehra Dun, Nain Singh reached Lhasa, having meticulously counted each pace and taken numerous clandestine compass readings and observations. He spent three months in the Holy City, taking 20 separate observations—both solar and stellar—that allowed him to establish its precise latitude (the pundits were not trained in the more complex skill of calculating longitude). Nain Singh determined Lhasa’s latitude to be 29.39 degrees, while modern atlases list it as 29.41 degrees. His altitude calculations placed the Tibetan capital at 11,700 feet, while today it is generally given as 12,000 feet; the discrepancy may stem from differences in the specific locations measured.
“In April 1866, Nain Singh learned that the Ladakhi caravan he had accompanied to Lhasa was preparing to return. The 500-mile journey took over two months and followed the ancient Jong-lam trade route, the highest highway in the world at 15,000 feet. Once again, Nain Singh recorded every step and took the necessary observations for his route survey before finally returning to British India after a year and a half.
“Montgomerie compiled all his mileages, bearings, altitudes, and latitudes into a map. ‘The Pundit deserves all praise; his work has withstood every test excellently. […]’ Lhasa’s longitude was calculated from the route survey, accurate to within a quarter of a degree. Nain Singh’s route survey, during which he covered 1,200 miles and counted 2,500,000 individual paces, disproved the assumption that existing maps of Tibet might be correct in some respects.
“Montgomerie’s full official report on the covert trip was sent to the Royal Geographical Society, revealing the Pundits’ secrets, including the fake prayer wheels, altered rosaries, and hidden sextants. This major breach of security is puzzling, as it endangered both the Pundits’ lives and future operations. The Journal was distributed only to fellows of the Society, which included Russian explorers. However, as long as it continued to publish such accounts and maps, St. Petersburg remained unconcerned. The Chinese would have had ample reason to intervene, but their London Legation was unaware of the Journal. It would have taken one inquisitive individual to alert them, and simple checks at Tibetan border posts could have jeopardized the entire endeavor.
“What motivated men like Nain Singh and Kishen Singh—who undertook a five-million-pace journey to Chinese Turkestan that lasted four and a half years—to endure such hardships for their imperial masters remains unclear. Perhaps it was Montgomerie’s inspirational leadership, who took pride in their achievements and viewed them as his sons. Or perhaps it was the knowledge that they were part of an elite group, each aware of being selected for this important task. Alternatively, Montgomerie might have instilled in them his own determination to fill in the gaps on the Great Game map before the Russians did. Regrettably, little is known about these men as individuals, as none left memoirs. Yet in Kipling’s masterpiece Kim, whose characters resemble those from Captain Montgomerie’s shadowy world, they receive fitting recognition.
“Hopkirk recounts more journeys and stories of other pundits in his book, but the points highlighted in this excerpt reveal intriguing parallels with our own less illustrious methods of measurement: calibration, counters (the rosary ‘rotates’ similarly to a Jones counter), a series of continuous measurements, temperature effects on measurements, a course map, and Montgomerie sahib, the authoritative figure certifying it all.”
This article first appeared in Measurement News, issue no. 82, March 1997.