FARM MAPS Farm maps, as the name implies, show the size, extent and shape, as well as the ownership of the farms. (Fig. 35.) The best farm maps are made with the topographic map used as a base; that is, the topographic map is enlarged, generally to a scale of four inches to a mile; the contour lines left off (brown figures may be left on), and the farm lines and other information added. An existing farm line map may easily be combined with the topographic map, or the description of the farms obtained at the proper courthouse and the maps constructed from the deeds. The best farm maps are so constructed. Of course, a survey of the farm is necessary if data are not obtainable other wise.
In the Eastern States, Pennsylvania, West Virginia, etc., the farms are irregular in shape, but a rectangular system of land division has-been provided by Acts of Congress at various times, requiring the subdivision of land surface into rectangles; so. at first six-miles square rectangles were laid out and referred to as townships and ranges, later it was decided that the six-mile square townships be further subdivided into rectangles of one square mile and known as sections, giving thirty-six sections to a township and numbered accordingly from one to thirty-six, with section one in the northeast corner and thence west and east alternately up to thirty-six, in the southwest corner. Later half section lines were also authorized to be run, further sub dividing the land into smaller but always rectangular por tions. Thus in a section of one square mile we have 64o acres, a half section 320 acres, r6o acres to a quarter section. The letter
of the law could not be followed out, as it is impossible to set out true rectangles on a spherical surface, and a certain error is obtained which is generally proportioned into the northern tier of sections. (Fig. 36.) A farm map is used to show the leases held by a company as well as the leases of a competing company; various colors are in use to indicate the various leaseholds. The maps also show the proper location of all wells.
The systems employed in surveying well locations are two in number, the rectangular method and the bearing method.
The rectangular method necessitates the use of a measuring tape or chain, or may be paced; and the locations are measured at right angles to the farm lines. Many States require this method for well locations and it is the most advantageous, as it is easily made and the distances from the property• lines are known. Such locations may easily be described verbally; thus the statement that a well on the J. Smith farm is 30o feet south of the north line and 40o feet east of the west line is easily understood and the corresponding location on one's own map made. (Fig. 35.) The bearing method necessitates the use of a transit or com pass, and the location is indicated by the distance a well is from the nearest corner stone of the farm and the magnetic bearing of that line. This method is inferior to the rectangular method. and should be avoided wherever possible. (Fig. 35.)