Its elevation as at present determined by trigonometrical observation is 2 9, 002 ft., but it is possible that further investigation into the value of refraction at such altitudes will result in placing the summit even higher.
The peak possesses no distinctive native name and has been called Everest after Sir George Everest, who completed the trigonometrical survey of the Himalayas in 1841 and first fixed its position and altitude.
De Morgan's other principal mathematical works were The Elements of Algebra (1835), a valuable but somewhat dry elementary treatise; the [[Essay]] on Probabilities (1838), forming the 107th volume of Lardner's Cyclopaedia, which forms a valuable introduction to the subject; and The Elements of Trigonometry and Trigonometrical Analysis, preliminary to the Differential Calculus (1837).
At first he purposed to study law; but this he abandoned on his father's death in 1794, and entered the army, obtaining a commission in the 12th regiment of foot, then stationed in India, where he rendered valuable assistance in the great trigonometrical survey.
He co-operated in the Danish and Hanoverian measurements of an arc and trigonometrical operations (1821-1848), and wrote (1843, 1846) the two memoirs Ãœber GegenstÃnde der hÃ¶heren GeodÃsie.