Hall, ASAPH

b. 1829. A istant at the Harvard Coll. Observatory 1857-62, and at U. S. Naval Observatory 1862-63; Prof. of Mathematics 1863. He has been connected with nearly all the eclipse expeditions sent out by the Observatory; was chief of a party for observing the transit of Venus at Vladivostock, Siberia, 1874, and again at San Antonio, Texas, 1882. In Aug. 1877 he made his most famous discovery, that of the two satellites of Mars.