Geographical Surveys West of the 100th Meridian (U.S.) Wheeler, George M. (George Montague), 1842-1905. Humphreys, A. A. (Andrew Atkinson), 1810-1883. Wright, Horatio Gouverneur, 1820-1899. text Washington : Govt. Print. Off., 1889. eng A. A. Humphreys, chief of engineers until June 1879. Succeeded by H. G. Wright. Date of publication for vol. 2. Astronomy and barometric hypsometry: 1877 (t.p.) United States--Surveys. United States--Discovery and exploration. West (U.S.)--Description and travel. United States. United States West. Available also through the Library of Congress Web site as a raster image. http://hdl.loc.gov/loc.gmd/g4050m.gct00105a http://hdl.loc.gov/loc.gmd/g4050m.gct00105b