The British went to India in 1808 to start the Great Trigonometric Survey to find out the name and geographic location of the tallest mountains in the world. The team began working in the Southern regions of India and slowly proceeded towards the Northern regions. They used a very large Theodolite (which required 12 men to carrying it) for calculating the heights of the mountains.
Photograph © William Bullock Clark
In 1830 they reached the foothills of the Himalayan mountains. Nepal were reluctant to permit British people into their country since they were suspicious about the political hostility and potential appropriation by them.
The British pursued with their survey from Terai, which is a region that is parallel to the Himalayan mountains and is in the South of Nepal. There observation centre here was up to one hundred and fifty miles away from the mountains.
During November in 1847, the acting surveyor general, Andrew Waugh recorded a number of findings from the Sawajpore observation centre which is located in the Eastern regions of the Himalayan mountain ranges. During that time, the highest peak on earth was considered to be Kanchenjunga. Due to curiosity, Andrew Waugh observed another peak that was behind it at a distance of one hundred and forty miles. Andrew Waugh’s official John Armstrong, also located the peak from the Western side and named it as ‘Peak B’. In 1849 James Nicolson, a member of the survey was sent to that region where he made two findings from Jirol which was one hundred and twenty miles away.
James Nicolson moved towards the east where he took more observations of ‘Peak B’ from five different locations, the nearest one being at a distance of one hundred and eight miles from the peak.
With all his findings James Nicolson moved back to Patna on the Ganges to go through his data. He had calculated an average altitude of 9,200 meters (30,000 feet) for ‘Peak B’. The measurement taken clearly showed that ‘Peak B’ was definitely taller than Kanchenjunga. Regrettably, James Nicolson suffered from malaria and was pressed to go back home, with the computation incomplete. One of the assistants of Andrew Waugh, Michael Hennessy had already started denominating the mountain peaks by using Roman numbers, and Kanchenjunga was given the name ‘Peak IX’ and ‘Peak B’ was designated as ‘Peak XV’.
In 1852, Radhanth Sikdar a mathematician from India and a Bengal surveyor from Dehradun recognized ‘Peak XV’ as the tallest peak. The official announcement that ‘Peak XV’ was the tallest mountain in the world was detained for few years so that all the calculations could be re-checked.
Andrew Waugh started to work on the data gathered by James Nicolson in 1854, and his employees worked with him for nearly two years on the computations, with issues related to light interaction, temperature, barometric pressure over a wide range of findings. Eventually, he declared his observations in a letter to his assistant in Kolkata.
In 1856 ‘Peak IX’ (Kanchenjunga) was announced to have a height of 28,156 feet (8,582 meters), and ‘Peak XV’ was having an altitude of 29,002 feet (8,840 meters). Andrew Waugh resolved that ‘Peak XV’ was the tallest mountain in the world.
Today the height of Peak XV (Mount Everest) is known as 29,029 feet or 8,848 meters.
In April 2015 Nepal suffered from a devastating 7.8-magnitude earthquake. This year (December 2017) ‘The Survey Department’ of Nepal has announced that over the next two years they are all set to start a project to remeasure Mount Everest to see if the earthquake had altered the mountain’s height.