also differ from the PLSS ideal of one square mile for other reasons, including errors and sloppy work by surveyors, poor instrumentation, and difficult terrain. In addition, the primary survey tool was the magnetic compass, which is influenced by local irregularities. Once established, even an imperfect grid remains in force, mainly because the monuments of the original survey, when recovered, hold legal precedent over subsequent resurveys. Alternatives and legacy systems The Public Land Survey System was not the first to define and implement a survey grid. A number of similar systems were established, often using terms like section and township but not necessarily in the same way. For example, the lands of the Holland Purchase in western New York were surveyed into a township grid before the PLSS was established. In colonial New England land was often divided into squares called towns or townships, and further subdivided into parcels called lots or sections. Sections are also used in land descriptions in the portion of northwestern Georgia that was formerly part of the territory of the Cherokee Nation. They are not, however, part of the PLSS and are irregular in shape and size. See Cherokee County, Georgia for more information on the historical reasons for this. Another exception to the usual use of sections and section numbering occurs when most of a parcel, or lot, falls under a body of water. The term "government lot" is used for such parcels and they are usually described separately from the rest of the section using single numbers (such as "Government Lot 5 of Section 15"). Also, parcels within a platted subdivision are often specified by lot number rather than using PLSS descriptions. Where Spanish land grants in Florida have descriptions that predate PLSS or even the U.S. itself, deviation from typical section numbering and size and shape often takes place. In an effort to honor these land grants after the U.S. took control of Florida, surveyors would use descriptions from confirmed land grants to establish their initial boundaries and created PLSS sections that extrapolated from those lines. Often, the amount of land left over in areas immediately surrounding the grants was grossly undersized or awkwardly shaped. Those tracts are referred to as "fractional sections" and often are not subject to township or range definitions. An example of such a legal description's beginning would read "Being a portion of Fractional Sec. 59, Township 0