From the early nineteenth century, Imperial Russian expansion threatened the increasing British dominance of India. In the 1860s, Captain Thomas Montgomerie hit on the idea of training natives from Indian border states to be surveyors, and have them explore the region covertly. Disguised as traders of Buddhist monks, the Pundits taught themselves to count their own paces and to walk at exactly 2,000 paces to the mile, whether uphill, downhill or on level ground. They were taught the use of sextant and compass, to navigate by the stars and to calculate altitudes by observing the boiling point of water. These loyal servants of the Raj, for personal prestige, the opportunity of employment or the sheer love of adventure displayed an extraordinary dedication to their British employers. Despite their precautions and tricks, some of them were sent back, imprisoned or tortured. Even so, they managed to map the Himalaya, Tibet and surrounding areas with remarkable precision, thereby helping the British to consolidate their rule in the Indian subcontinent.