Portrait · as reproduced in The Modern Review, 1933
Radhanath Sikdar
1813 — 1870
Legend gives him Mount Everest. The record gives him something larger: the mathematics of a survey that mapped a subcontinent.
In December 1831, an eighteen-year-old from Jorasanko in Calcutta was hired by the Great Trigonometrical Survey of India as a "computer" — a human calculator — for thirty rupees a month. He had studied mathematics at Hindu College and read Newton. George Everest, the Survey's head, soon wrote that even in Europe his talents would rank very high, and kept him on the job.
Radhanath Sikdar spent thirty-one years turning angles measured on hilltops into the shape of India. He rose to Chief Computer, ran Calcutta's weather register, wrote the hardest chapters of the Survey's manual, and stood up to a magistrate on behalf of his porters. After he died, his name was quietly cut from the preface of that manual. Today he is famous mainly for a calculation that historians now doubt he made.
Thirty-one years of reckoning
The lifeline
1813
Born in October in Jorasanko, Calcutta; enters Hindu College in 1824
1831
Joins the Great Trigonometrical Survey as a computer, aged 18, on ₹30 a month
1843
Fined ₹200 for protesting a British magistrate's misuse of the Survey's porters
1851
Chief Computer in Calcutta; the Manual of Surveying credits his chapters
1862
Retires from the Survey and teaches mathematics at the General Assembly's Institution
1870
Dies on 17 May at Chandernagore, upriver in French India, aged 56
By the numbers
The measure of him
₹30
His monthly pay when he joined the Survey in 1831, aged 18
31 yrs
In the Great Trigonometrical Survey, from 1831 to 1862
₹200
The fine he paid in 1843 for defending survey porters from forced labour
29,002 ft
The Survey's 1856 height for Peak XV, within 30 ft of today's 29,032
What he gave the Survey
The work
1830s
Reducing the Great Arc. Under Everest he turned field observations into positions on the earth, correcting for its curvature, for refraction and for temperature. The arc, measured along a meridian through the length of India, was completed in 1843.
1851
A Manual of Surveying for India. Edited by Captains Thuillier and Smyth. Its preface credited Sikdar with the technical and mathematical chapters.
1850s
The Calcutta weather register. As superintendent of meteorological observations he ran hourly readings at the government observatory, and abstracts appeared in the Journal of the Asiatic Society of Bengal.
1854
Masik Patrika. With Peary Chand Mitra he founded a Bengali monthly in plain, everyday language, written for women's education.
1856
Peak XV, 29,002 ft. The Survey announced it as the highest mountain on earth. Disputed By long tradition Sikdar computed it and ran in to tell Andrew Waugh. Historians who have read the Survey's records argue the reductions were done in Dehra Dun while his office was in Calcutta.
Erased, then mythologised
Recognition
In his lifetime & after
Hired as a human calculator on ₹30 a month
Fined ₹200 for standing up for the Survey's porters
In 1865 Peak XV was named after Everest. The Survey's Indian staff went unnamed
The 1875 edition of the Manual dropped his credit. The Friend of India called it "robbery of the dead"
Today
On 27 June 2004 India Post honoured him on a Great Trigonometrical Survey stamp, alongside Nain Singh
He is popularly hailed as "the man who measured Everest"
Historians now dispute that claim, and the argument has put his documented work back on the record
Everest's 1838 verdict stands: few in India, European or Indian, could compete with him
The city that schooled him
Calcutta
He was born in Jorasanko, in north Calcutta, and was educated at Hindu College, the new English-language college of the city's reformers. After nearly two decades of computing in the hills around Dehra Dun, he came home to run the Survey's mathematics. He died upriver, in French Chandernagore.
1817
Hindu College founded in Calcutta. Sikdar enters it in 1824
1851
Returns to Calcutta as the Survey's Chief Computer
~35 km
Up the Hooghly to Chandernagore, where he died in 1870
"Even in Europe his mathematical talents would rank very high."
— George Everest, on Sikdar, 1838
