SURVEYING (from survey, from AF. stir vccr, survoir, from Lat. supervidcre, to overlook, oversee, from super, above + videre, to see). The art of ascertaining by measurement the shape and size of any portion of the earth's surface, and representing the same on a reduced scale on maps in a conventional manner. Surveying is supposed to have originated in Egypt, where property boundaries were annually obliterated by the inundations of the Nile. In Rome surveying was considered one of the liberal arts, and the measurement of lands was intrusted to public officers (agrimensorcs) who enjoyed certain privi leges; and it is probable that the system of measurement praetieed by them was similar to the cruder methods of plane surveying practiced at the present time. The higher development of surveying method is of comparatively recent date.
Surveys are broadly separated into two classes, determined by the extent of the area surveyed. Most surveys comprise the measurement of com paratively small areas in which all practical re finements are met if we consider the areas abso lute planes, neglecting the curvature of the earth's surface. The methods of measuring such
areas is usually denominated plane surveying. Certain surveys of modern times, however, in clude areas so large that it is necessary to take into account the curvature of the earth's sur face, and the methods of measuring such areas are termed geodetic surveying or geodesy (q.v.)..
Briefly summarized, plane surveying includes land surveying, topographic surveying, and hy drographie surveying (see EvimocriAeny), min ing surveying, railway surveying, and city sur veying. Geological surveying is a development of topographical surveying in which the outcrops of the earth's rock formation are located and de noted on topographical maps. Geodetic survey ing is a class by itself, as is also photographic surveying (q.v.).