HOLDEN, Edward Singleton, astronomer, born in St. Louis, Missouri, 5 November, 1846. He was graduated at the scientific school of Washington university in 1866, and in that year assisted Dr. Benjamin A. Gould in collecting materials for the "Investigations in the Military and Anthropological Statistics of American Soldiers." He was graduated at the United States military academy in 1870, and appointed 2d lieutenant in the 4th artillery. He served at Fort Johnson, North Carolina, until 1871, when he returned to West Point as assistant professor of philosophy. In 1872 he was transferred to the engineer corps, serving as instructor in engineering. In March, 1873, he resigned his commission in the army, became professor of mathematics in the United States navy, and was ordered to the naval observatory at Washington, as assistant in the work of the transit circle. Subsequently he was assistant to Professor Simon New-comb in charge of the 26-inch equatorial telescope. His "Monograph of the Central Parts of the Nebula of Orion" is an exhaustive treatise on all of the observations hitherto made upon that subject, including several years' work of his own (Washington, 1882). In 1876 Professor Holden went to London to examine the South Kensington loan collection of scientific instruments. He gave much attention to the methods of testing chronometers, and in 1879 the time-ball on the Western Union telegraph building in New York was erected according to his plans. On 6 May, 1878, he observed the transit of Mercury, with Dr. Henry Draper, at Hastings, and in that year was placed in charge of a party to observe the total eclipse of 29 July in Colorado. In 1881 he became professor of astronomy in the University of Wisconsin and director of the new Washburn observatory. He remained there till 1886, and issued four volumes of publications. He was also head of the division of climate and rivers in Professor Raphael Pumpelly's northern trans-continental survey. In 1882 he terminated his official connection with the navy, but was placed in charge of the government expedition to the Caroline islands, to observe the total eclipse of the sun on 6 May, 1883. In 1886 he became president of the University of California and director of the Lick observatory on Mt. Hamilton, San Jose. He is a member of numerous scientific associations, and has received the degree of LL.D. from the University of Wisconsin (1886), and from Columbia (1887);, He has published "Astronomy for Students, with Professor Simon Newcomb (New York, 1880); and is the author of "Sir William Herschel: his Life and Works" (New York and London, 1881). His writings include "On the Adopted Value of the Sun's Apparent Diameter," " On the Number of Words used in Speaking and Writing," "On the Proper Motion of the Trifid Nebula," "The Cipher Despatches," "Studies in Central America Picture-Writing," "Observations on the Transit of Mercury at Mt. Hamilton," "List of Twenty-three New Double Stars discovered at the Caroline Islands by Edward S. Holden and Charles S. Hastings," and "A System of Local Warnings against Tornadoes."