HALL, ASAPH (1829-1907), American astronomer, was born on Oct. 15, 1829, at Goshen, Conn., and left school when 13 years of age to support the family after the death of his father. At 16 he became a carpenter and his desire to be an architect led him to study mathematics. Nine years later he was able to spend a year and a half at Central college, McGraw ville, N.Y., and later a summer term at the University of Michi gan, where, under Brunnow, he made his first acquaintance with astronomical instruments. Determined to become an astronomer, he went to Cambridge, Mass., in 1857, as an assistant to Prof. Bond at $3 a week. In 1862 he had made such progress that he was appointed an aid, and one year later professor in mathematics at the U.S. Naval Observatory, Washington, D.C. This position he held until his retirement in 1891. From 1895 to 1901 he was professor of astronomy at Harvard. At the Naval observatory Hall had the 26 in. equatorial telescope under his charge from 1875 to 1891. His work with it was chiefly in three fields; planetary observations and the orbits of their satellites; observa tions of double-star orbits; determinations of the stellar parallax. In each of these fields Hall's extensive observations were of great value. His most spectacular achievement was the discovery in 1877 of the two satellites of Mars, whose orbits he calculated. He died at Annapolis, Md., on Nov. 22, 1907.