(1813 – 17 May 1870) was an Indian mathematician who, among many other things, calculated the height of Peak XV in the Himalaya and showed it to be the tallest mountain above sea level. Peak XV was later named Mount Everest.
Radhanath was born as youngest child of Tituram, a resident of Jorasanko in Calcutta. Radhanath Sikdar was educated at “Phiringi” Kamal Bose’s School andHindu School in Calcutta, India. Alone among the great Derozians he took to science as his life’s mainstay. He worked for the Surveyor General of India, a division of the british Raj in India. He joined the Great Trigonometric Survey in 1831.
When in 1831 George Everest was searching for a brilliant young mathematician with particular proficiency in spherical trigonometry, the Hindu College maths teacher Dr. John Tytler superlatively recommended his pupil Radhanath, then only 19. Radhanath joined the Great Trigonometric Survey in 1831 December as a “computor” at a salary of thirty rupees per month. Soon he was sent to Sironj near Dehra Dun where he excelled in geodetic surveying. Apart from mastering the usual geodetic processes, he invented quite a few of his own. Everest was extremely impressed by his performance, so much so that when Sikdar wanted to leave GTS and be a Deputy Collector, Everest intervened, proclaiming that no government officer can change over to another department without the approval of his boss. Everest retired in 1843 and Col. Waugh became the Director.
After 20 years in the North, Sikdar was transferred to Calcutta in 1851 as the Chief Computor. Here apart from his duties of the GTS, he also served as the Superintendent of the Meteorological department. Here he introduced quite a few innovations that were to remain standard procedure for many decades to come. The most notable was the formula for conversion of barometric readings taken at different temperatures to 32 degrees Fahrenheit.
At the order of Col. Waugh he started measuring the snow-capped mountains near Darjeeling. Compiling data about Peak XV from six different observations, he eventually came to the conclusion the Peak XV was the tallest in the world. He gave a full report to Waugh who was cautious enough not to announce this discovery before checking with other data. When after some years, he was convinced, only then did he publicly announce the same. The norm, strictly followed by Everest himself, was that while naming a peak, the local name should be preferred. But in this case, Waugh made an exception. He paid a tribute to his ex-boss by proposing that the peak be named after Everest. Everest agreed, and Sikdar was conveniently forgotten.
It appears that while Everest and Waugh both extolled him for his exceptional mathematical abilities, his relations with the colonial administration were far from cordial. Two specific instances are on record.
In 1851 a voluminous Survey Manual (Eds. Capt. H. L. Thullier and Capt. F. Smyth) was published by the Survey Department. The preface to the Manual clearly and specifically mentioned that the more technical and mathematical chapters of the Manual were written by Babu Radhanath Sikdar. The Manual proved to be immensely useful to surveyors. However, the third edition, published in 1875 (i.e., after Sikdar’s death) did not contain that preface, so that Sikdar’s memorable contribution was de-recognized. The incident was condemned by a section of British surveyors. The paper Friend of India in 1876 called it ‘robbery of the dead’.
It is also on record that Sikdar was fined a sum of 200 rupees by the British court in 1843 for having vehemently protested against the unlawful exploitation of survey department workers by the Magistrate Vansittart. The incident was reported in detail in The Bengal Spectator edited by another great Derozian Ramgopal Ghosh.
In 1854, he along with his Derozian friend Peary Chand Mitra started the Bengali journal Masik Patrika, for the education and empowerment of women. He used to write in a simple and uncluttered style that was rather atypical for the age.
Sikdar had retired from service in 1862, and was later appointed as teacher of mathematics at the General Assembly’s Institution (now Scottish Church College).
He died on 17 May 1870 at Gondalpara, Chandannagar in his villa by the side of the Ganga.
It is said that in recognition of Sikdar’s mathematical genius a German learned society made him a Corresponding Member in 1864, a very rare honour those days.
The Department of Posts, Government of India, launched a postal stamp on 27 June 2004, commemorating the establishment of the Great Trigonometric Survey in Chennai, India on 10 April 1802. The stamps feature Radhanath Sikdar and Nain Singh, two significant contributors to society. The Great Arc refers to the systematic exploration and recording of the entire topography of the Indian subcontinent which was spearheaded by the Great Trigonometric Survey.