Brilliant Sikdar, discoverer of height of Mt. Everest and Survey of India 1800s

 Today at quiz contests, the kids easily answer what the height of Mt. Everest is before blinking our eyes. None of us know how much hard work, sacrifices and mounds of mathematical calculations were made by the people during the great survey undertaken in 1800s by the British under  William Lampton, George Everest and Andrew Waugh.

Radhanath Sikdar discovered the height of Everest. Veethi
During the colonial period under the East India company' rule  it was an eminent  Indian  mathematician Radhanath Sikdar (1813-1870), of  The Great Trigonometric Survey of India (GTS),  who had discovered  in 1852 the highest summit, (then called Peak XV), in the world. Several years later, it was confirmed by the Surveyor-General of India, George Everest. The highest peak was later known as Mt. Everest. Like George Everest himself, Sikdar never saw the snow-clad Mt. Everest.

Mt. Everest .Daily Express
  The  border area of  Nepal-Tibet  was  a god-forsaken one, a forbidden region and it was a difficult terrain  for the survey crew to work with while  mapping  the Himalayan region and the peaks. Many higher peaks and the terrain  below them were glaciated and subjected to glacial erosion. This resulted in unstable slopes and pointed peaks, making the climb a tough one.  Surveyors  in 1849 could cover lesser summits, taking measurements of Peak XV from six different locations with  theodolite instrument. They covered a distance of 100 miles south of the peak. More daunting task was the light reflected off snow at distances, making it tough to get the same measurements twice. A difference of 1000 to 1300 feet in the data caused by refraction had to be  mathematically corrected by the mathematical team based in Calcutta.
Survey of India emblem. en.wikiprdia.org
Surveyor Lampton FRS (c. 1753 – 20 or 26th January 1823), soldier and geographer toiled 17 years of his life in his  project (called Triangulation Survey),
William Lampton.Frontline
involving physical measurements. He died in 1823 of TB at the age of 70 while camping with his team on the high mountain.

George Everest, Lampton's successor changed  the techniques and the apparatus and took another 20 years, conducting surveys. Only in 1843 the survey team could reach  the Himalayas under Andrew Waugh, George's successor.  
Great Theodolite by Jesse Ramsdenuded by lambton  en.wikipedia.org
The survey took into account the elliptical shape of the earth that varies from place to place. Yet another factor is density of the rocks which led to the theory of Isostasy - the state of gravitational equilibrium between Earth's crust and mantle such that the crust (made of rocks) "floats" at an elevation that depends on its thickness and density.

Everest (4 July 1790 -1 December 1866), a Welsh surveyor and geographer who became assistant to Colonel Lampton in 1816 embarked on the mammoth task of  the Trigonometric Survey of the Indian subcontinent, involving various mathematical methods and it took  20 to 25  years for him to complete the survey. The  survey had its early beginning in Madras (now Chennai) in 1802  under William Lampton, an army officer. The survey involved several thousand Indians and was named the Great Trigonometrical Survey (GTS) in 1819. He retired from the survey in 1843.

The detailed survey over a stretch of more than 1,600 miles, covered vast mountainous wooded areas and  rugged terrains. The employees mainly Indians in thousands, had to work under various unfriendly weather conditions, far away from the human settlements. Countless people lost their lives owing to  wild animal attacks, mosquito bites and poisonous snake bites.
Andrew Scott Waugh (GTS of India) Wikipedia
George Everest,The Great Trignometric Survey of India Wikipedia Pinterest
Radhanath Sikdar  in 1852 met his  superior Andrew Waugh in the survey office in the hill station of Dehradun and excitedly told him that he had finally calculated the highest peak in the Himalayas. He arrived at the figure after years of  hard work with  mind-boggling mathematical calculations. Sikdar, aged 39 was mainly instrumental in arriving at the correct figure after going through countless data gathered during the tiresome survey of the topography. Though Sikdar came up with  his important discovery,  he  remained an  unsung hero.
The Great Arc: India was Mapped and Everest was Named: John Keay. Amazon.com
Sikdar had a sound knowledge of mathematics  and his skills were fully utilized by the survey. George Everest himself acknowledged that Sikdar was a  "mathematician of rare genius," according to the British historian John Keay, author of two books on the subject, told BBC News Online. He further mentioned that
"His greatest contribution to the computation was in working out and applying the allowance to be made for a phenomenon called refraction - the bending of straight lines by the density of the Earth's atmosphere." George Everest further commented on Sikdar: “There are few in India, whether European or native, that can at all compete with him. Even in Europe these mathematical attainments would rank very high .... there are a few of my instruments that he cannot manage; and none of my computations of which he is not thoroughly master. He can not only apply formulae but investigate them." 


Sikdar's great contribution was not known to countless  Indians and  is now part of the Great Arc Exhibition in London's vibrant Brick Lane. The Indian Government-sponsored exhibition celebrates 200 years of the mapping of the Indian subcontinent.

Though the discovery was made as early as 1852, the public announcement got delayed  till 1856 because of recheck and final confirmation. Andrew Waugh made a formal announcement four years later, renaming the peak after his mentor and predecessor George Everest despite his protests. As part of the work,  the density of the earth, its  angle of curvature and heights of innumerable peaks all along the curve had to to be minutely calculated. Extrapolation and calibration of various survey data needed  high degree of mathematical skill and Sikdar's work was a stupendous one.  

Sikdar, who was 39 when he made his discovery, was one of the survey's  unsung heroes.The GST was greatly indebted to him for hid monumental work in solving the jigsaw puzzle with respect to the height of Everest. The son of a Bengali Brahmin,  he was born in October 1813 in Jorasanko, Calcutta's old city. He majored in mathematics at the famous Hindoo college, Kolkata and also gained basic knowledge in English.  At the Hondoo College Newtonian mathematics and physics were taught by Tytler and Ross and Sikdar was the first Indians to master Newtonian mathematics and physics. He  Joined Great Trigonometrical Survey in 1832.  He remained a bachelor through out his life and his passion was maths and was good at solving, tricky, knotty odd mathematical calculations. He became the right-hand man of George Everest  at Dehra Dun in measuring the Great Arc and wrote the scientific and technical chapters of the Survey Manual. Having spent 20 years in the North, Sikdar was transferred to Calcutta in 1851 as the Chief Computer. Here his additional  duties included serving  as the Superintendent of the Meteorological department.  His  few innovations in meteorology  became standard procedures for many decades to come. The most significant finding  wasa practical  formula for conversion of barometric readings taken at different temperatures to 32 degrees Fahrenheit.

Skidar became a recluse in the later years and died on 17 May 1870 at his own villa in Chandan Nagar, then a French colony. Earlier after retirement in 1862, he taught maths at  General Assemblies Institution and was awarded  corresponding Membership of Bavaria Natural History Society under German Philosophical Society in 1864, a rare honor bestowed on a foreigner. Along with one Peary Chand Mitra, Sikdar edited a women's magazine called  Masik Patrika (the monthly magazine) of the Calcutta Art and Craft Society in 1854. He believed in woman's empowerment and spoke against polygamy, child marriage and racial discrimination. He wholeheartedly  encouraged widow's remarriage.
Mauna kea and Mt. Everest. Business Insider
 Tit-Bits:
01. Geologically speaking, Mount Everest, a part of the Himalayan range, is slowly growing inches by inches because of plate tectonic movements between the Indian and Eurasian plates. Slow collusion of these plates pushes the crust all along the Himalayan mountain chain. o, areas near the boundary are pone to tremors due to adjustments made by the moving blocks of rocks.
Indian plate colliding with the Eurasian plate and make mountains like the Himalaya.www.public.asu.edu
02. The height  of Mt. Everest has risen higher since Sikdar's findings. In 1955, the mountain "grew" by 26 ft to 29,028 ft (8 m to 8,848 m). It  grew another 7 ft (2 m) in 1999.
Today, the world's highest mountain stands 29,035 ft (8,850 m) high above the MSL(mean sea level).

03. The GST under George Everest was earlier known as the Triangulation Survey started by William Lampton at Madras  (Tamil Nadu) to survey the Geomorphology of the southern regions first.

04.  He assisted in the publication of many technical surveys. When the third survey manual came out  in 1875 there was no acknowledgement  of Sikdar's  major contribution and it was condemned by many British higher ups whose unanimous opinion was Sikdar was a great mathematician of exceptional ability and deserved better recognition and the survey owed him a lot.

Ref:
https://www.quora.com/How-did-the-Indian-mathematician-Radhanath-Sikdar-calculate-

https://www.facebook.com/public/William-Lampton

https://en.wikipedia.org/wiki/Radhanath_Sikdar

By Soutik Biswas, BBC News Online - Monday, 20 October, 2003, 02:09 GMT 03:09 UK
http://www.slideshare.net/ruchirgpt1987/radhanath-sikdar

http://en.banglapedia.org/index.php?title=Shikder,_Radhanath