A Value of the Solar Parallax from Meridian Observations of Mars at the Opposition in 1877.

Washington, D.C.:: Government Printing Office, 1881., 1881. First edition. 4to. 43 pp. Tables. Original printed wrappers; small stain to front wrapper, spine worn. Early ownership signatures on cover & title of George Davidson. Very good. WITH: HALL, Asaph. Observations and Orbits of the Satellites of Mars with Data for Ephemerides in 1879. Washington, D.C.: Government Printing Office, 1878. 4to. 51 pp. 11 tables. Printed wrappers; rear cover loose. Early ownership signature on cover. Good. Hall, professor of astronomy at Harvard, was an expert computer (truncated) of orbits and was the first to discover satellites of Mars, which he named Deimos and Phobos. Includes an early photographic portrait of Hall extracted from an unknown source. Davidson founded the observatory of his name in San Francisco and from 1876-1886 had charge of the main triangulation and astronomical work on the western coast. DSB VI. (Inventory #: S7483)