Euler, LEONHARD

Euler, LEONHARD, a distinguished mathematician, born 15th April 1707, at Basel, where he afterwards studied under John Bernoulli, and was the friend of Daniel and Nicholas Bernoulli. At the age of nineteen he was second in the contest for a prize offered by the Academy of Paris for the best treatise on the masting of ships. His friends the Bernoullis had been called to St Petersburg by Catharine I., when she founded the Academy, and in 1727 they induced Euler to settle in that capital, where in 1730 he was appointed to the chair of Physics, in 1733 of Mathematics. From that time he continued to labour in the field of mathematics with an ardour that excited the generous rivalry of the Bernoullis. More than half the mathematical treatises in the 26 quarto volumes published by the St Petersburg Academy from 1727 to 1783 are by Euler, and at his death he left more than 200 treatises in MS., which were afterwards published by the Academy. The French Academy of Sciences awarded him its prize on several occasions, and in 1740 his treatise on Tides shared the prize with those of Maclaurin and Daniel Bernoulli. In 1741 he accepted the invitation of Frederick the Great to Berlin, and there published a great number of valuable papers. In 1766 he returned to St Petersburg, where he died, September 18, 1783. The last years of his life were spent in total blindness, amid which he still pursued his researches, dictated his well-known Introduction to Algebra to his servant, and perfected, with some assistance, his theory of the moon's motion, constructing new tables, and carrying in his wonderful memory all the elaborate computations involved in his difficult task. After his return to St Petersburg, he also prepared his Lettres à une Princesse d'Allemagne (3 vols. 1768-72), in which, along with much theory unsoundly applied, there is a clear exposition of the most important facts in physics. Euler was of an upright, amiable, and religious character, and a man of wider general culture than might have been looked for in one who pursued his special studies so keenly. His proper domain was the abstruser parts of pure mathematics, and here his principal works include his Theory of Planetary Motion, Introduction to the Analysis of Infinites, Institutions of the Differential and of the Integral Calculus, and Dioptrics, which are all, as well as his Opuscula Analytica, in Latin. See Radio's Leonhard Euler (Basel, 1884) and Die Baseler Mathematiker (ib. 1884).