Wheeler From 1869-79 extensive explorations were made in the West under direction of Capt. G. M. Wheeler of the United States army engineers. The title of the organ ization was United States Geographical Surveys west of the 100th meridian. Many hachured topographic maps .were prepared of parts of Arizona, Utah, New Mexico and Colorado and the geology of various regions was mapped by G. K. Gilbert, A. It Marvine, E. E. Howell, J. J. Stevenson, I. C. Russell and others. The principal results were published in three quarto volumes issued in 1875, 1881 and 1889.
United States Geological In 1876 there were four geological surveys in progress, the Hayden, King, Wheeler and Powell with some duplication of work, a condi tion which roused so much criticism that Con gress referred the consideration of the con tinuance of the work to the National Academy of Science. That body recommended the sub stitution of a single organization for the topo graphic and geologic work, and accordinglai 1879 Congress created the United States logical Survey (q.v.) as a bureau of the In terior Department. This survey has been continued by annual appropriation (about $1,500, 000 in 1917). It has made detailed topographic maps of 40 per cent of the area of the United States. Large areas have also been mapped geologically, considerable public land classified in various ways and water resources determined. The maps are on various scales and sold at cost of paper and printing, most of them by the survey. Many of the geological reports are for gratituous distribution. Two hundred and eleven folios of the Geologic Atlas of the United States have been issued which sell from 25 to 75 cents each.
Reclamation Many detailed sur veys have been made by the Reclamation Serv ice in connection with its various projects, and many suggested ones. Some of the resulting maps have been issued in the various annual reports of the bureau and others are filed.
Isthmian Many surveys have been made by parties sent to the Central America and Panama by the United States gov ernment to obtain data for canal routes.
General Land The General Land Office created in 1812 (see Punic LANDS) and since 1849 a bureau of the Interior Department, has surveyed a large proportion of the public lands in the States west of the Mississippi River, except Texas, and also Ohio, Illinois, Indiana, Florida, Alabama, Wisconsin and Michigan. Many of the State lines were run by the Land Office. In the surveys by this bureau public lands are divided into townships six'miles square, comprising 36 sections one mile square, the latter divided into quarter sections of 160 acres and in some cases, minor divisions, a system devised by Lieutenant-Colonel Mans field in 1803. The enclosing lines are due north
and south and east and west and owing to con vergence of meridians and varying length of parallels at different latitudes the divisions are only approximate. The townships are num bered east and west from prime meridians, and north and south from standard parallels. The sections, ordinarily a mile square, are numbered thus : Thus, for instance, a piece of land is desig nated NWJ Sec. 28, T. 19 S., R. 28 W. New Mexico. Farther_ subdivision is indicated by 1/4, 1/4 sections, and odd areas as lots. The maps are prepared on a scale of two inches to one mile and in most cases the con figuration of the land is represented by hachures excepting in later work in a few Indian reservations where contour lines have been used. This mapping covers -most of the smooth surfaced or rolling lands but large areas of mountain lands are not yet subdivided. The maps are not issued but held in file in the general land office and local land offices in various public land States. The bureau does, however, issue general maps of the States and of the United States compiled largely from its own surveys.
Coast and Geodetic The work of mapping the coast of the United States was initiated by Congress, 10 Feb. 1807, on recom mendation of Thomas Jefferson, with an appro priation of $50,000. F. R. Hassler was its first superintendent, beginning work in 1816 and continuing to 29 April 1818 as a bureau of the Treasury Department. The surveys were then continued by the United States army en gineers and by officers of the navy until the bureau resumed operations again in 1832 under the Navy Department with Hassler again as superintendent. On reorganization late in 1843 A. D. Bache became superintendent and he con tinued in charge until his death in 1867. Pierce, Patterson, Hilgard, Thorn, Mendenhall, Duf field, Pritchett, Tittmann and Jones were later superintendents. The geodetic work or deter mination of the form of the earth was made an additional function of the survey in 1878. The survey has prepared charts of the coasts and exterior waterways of the United States and of parts of its possessions, and mapped more or less of the coast, the District of Columbia and other areas. Many special reports on geodesy, tide tables and scientific researches of the bureau have been issued. The charts which are issued in sheets of various sizes and scales are sold at low rates directly by the bureau and by local agents in seaboard cities.