Sir George Everest

In 1818, Sir George Everest joined Col. Lambton. In 1822, Lambton continued the survey from Hyderabad towards Nagpur. But he died on the road at Hinjunghat on 20th January, 1823. After the death of Col. Lambton, George Everest assumed the control of the Great Trigonometrical Survey. He was a worthy successor who had made the Arc his life's work. Though Everest saw the Himalayas only once in his career, the loftiest peak there and, consequently, in the world, was given his name: acknowledgement of the painstaking scientific endeavour that crawled through the subcontinent's vast burning expanse to make possible the measurement of the snow capped Himalayas.

Everest was born in 1790. The Great Trigonometrical Survey India, begun at Cape Comorin in 1806 by William Lambton, would then run almost 2,400 kilometers north to the Himalayas, extending over 20 along the meridian. During this tremendous undertaking, Everest was relentless in his pursuit of accuracy. To that end, he made countless adaptations to the surveying equipment, methods, and mathematics in order to minimize problems specific to the Great Survey: immense size and scope, the terrain, weather conditions, and the desired accuracy.

In June of 1830, George Everest become the Surveyor General, in addition to his post as superintendent of the Great Trigonometrical Survey. Everest's first work on the Arc was to create a baseline near Dehra Dun using the Colby compensating bars. The 39,183,783 ft baseline was meticulously surveyed, using every precaution to safeguard its accuracy. He then connected the Dehra Dun baseline to the Sironj baseline, a distance of over 400 miles, using a triangulation gridiron. This was across a vast plain, which necessitated the construction of masonry towers, designed by Everest, most of them 50 feet high. The great theodolite was then hoisted to the top, and Everest performed and recorded the observations. By day, heliotropes were placed on distant points, reflecting bright flashes of sunlight towards the survey towers. On days when refraction became a problem, observations were taken at night, using an Indian version of the reverberatory lamp, which could be seen for thirty miles, and sometimes by using cylindrical blue lights whose visible range could exceed fifty miles. Transportation was interesting; a typical foray included 4 elephants for the tiger-wary principals, 30 horses for the military officers, and 42 camels for supplies and equipment. The 700 or so laborers traveled on foot. Progress was steady; by May of 1836 half of the gap between Sironj and Dehra Dun had been completed, and the rest was completed the following season.

Everest next turned his attention to astronomical observations throughout the arc of meridian, especially at Kalianpur (24 degrees 07'). Unfortunately, ill health prevented him from completing this task, so it was Andrew Waugh who stepped in to finish the job, including re-measuring the Bidar baseline with the Colby compensating bars. The subsequent error of closure between the observed and computed length of the Bidar base, after 425 miles and 85 triangles from Sironj, was 0.36 feet in a line length of 41,578 feet.

By 1841, twenty-three years had passed from the time Everest had first begun work on the Great Arc. It would take him two more years to complete the computations, and compile the results before he retired and returned to England.