WATSON, James Craig, astronomer, born in Fingal, Ontario, Canada, 28 January, 1838; died in Madison, Wisconsin, 23 November. 1880. He was of American ancestry, and was born during a visit of his parents to Canada. He was graduated at the University of Michigan in 1857, and in his junior year performed the phenomenal task of reading La-places Mecanique celeste from beginning to end. During his final year he was the sole pupil in the observatory, where he spent part of his time in grinding lenses and in the construction of a telescope. On his graduation he became assistant to the chair of astronomy, and in his work he displayed such aptitude as an observer and such rapidity in his computations that in 1859 he was appointed professor of astronomy. In 1860 he was given the department of physics, but in 1863 resumed charge of the department of astronomy, and was made director of the observatory. In 1879 he was called to the chair of astronomy and the directorship of Washburn observatory in the University of Wisconsin. He discovered a comet on 29 April, 1856, while he was still an undergraduate, and on 20 October, 1857, he discovered independently an asteroid that had been found a few days previously. In 1858 he devoted his attention to Donati's comet, and his computation of its orbit is accepted as authoritative. His first independent planetary discovery was on 14 September, 1863, of the asteroid Eurynome, and on 9 January, 1864, the comet known as 1,863, vi., which had previously been noted, was found by him. He discovered on 7 October, 1865, the asteroid that has since been named Io, and on 24 August, 1867, he discovered Minerva, and on 6 September, 1867, Aurora. During 1868 he added six minor planets to the solar system. He was a member of the government expedition to observe the solar eclipse at Mount Pleasant, Iowa, in 1869 and was sent on a similar mission in 1870 to Carlentini, Sicily. In 1874 he was appointed to the charge of the American party that observed the transit of Venus from Peking, China. On this expedition he made his eighteenth planetary discovery, to which he gave the name Juewa. Professor Watson was one of the judges of award at the World's fair in Philadelphia in 1876, and wrote a "Report on Horological Instruments." In 1878 he had charge of the government expedition to Wyoming to observe the total solar eclipse, and on that occasion he paid special attention to the existence of an intra-Mercurial planet as well as that of an extra-Neptunian one, in both of which he believed. On 29 July, 1878, he determined the exact locality of what he believed to be "Vulcan," and he further satisfied himself of the existence of a second intra-Mercurial planet. Subsequent to his removal to Madison he devoted his energies to remodelling the observatory structure, and introducing original features of his own devising. For many years he was actuary of the Michigan mutual life insurance company, and by commercial enterprises he acquired a moderate fortune, of which he bequeathed $16,000 to the National academy of sciences, the income of which is used partly as a research fund and partly for the Watson medal. The total number of asteroids that he discovered was twenty-three, and in 1870 he received the Lalande gold medal from the French academy of sciences for the discovery of six asteroids in one year. In 1875 the khedive of Egypt made him knight commander of the Imperial order of the Medjidich. The degree of Ph. D. was conferred on him by the University of Leipsic in 1870, and that of LL.D. by Columbia in 1877. In 1867 he was elected to the National academy of sciences. His contributions to astronomical journals were frequent, besides which he published a "Popular Treatise on Comets " (Philadelphia, 1860); "Theoretical Astronomy" (1868) ; and "Tables for Calculation of Simple and Compound Interest and Discount" (Ann Arbor, 1879).