Simon Newcomb, an American astronomer, born at Wallace, Nova Scotia, March 12, 1835. He came to the United States in his youth, taught school several years in Maryland, and was employed as computer on the " Nautical Almanac" for 1857. He began his original investigations in theoretical astronomy in 1858, and in 1861 was appointed professor of mathematics in the navy, and ordered to the naval observatory. He negotiated the contract for the great telescope authorized by congress, supervised its construction, and planned the tower and dome in which it is mounted. He was a member and secretary of the commission created by congress in 1871 to provide for the observation of the transit of Venus, Dec. 9, 1874. The work of organizing parties, selecting their stations, and planning the system of observation fell chiefly on him. In 1872 he was elected a foreign associate of the royal astronomical society of England; and in 1874 he received that society's gold medal for his tables of Neptune and Uranus, and in the same year was elected a corresponding member of the institute of France. His most important astronomical works are: "On the Secular Variations and Mutual Relations of the Orbits of the Asteroids" (1860); " Tables of the Planet Neptune;" "Investigation of the Solar Parallax" (1867); "On the Action of the Planets on the Moon," communicated to the French academy during a visit to France (1871); and "Tables of Uranus" (1873). He has also published "A Critical Examination of the Financial Policy during the Southern Rebellion" (1865), and has contributed to the "North American Review" and other periodicals articles on political economy, etc.