On Tuesday 16 September 2008 21:41:13 Pat Naughtin wrote: > Dear All, > > You might be interested in this clear description of the PLSS the > Public Land Survey System used in many parts of the USA. They write: > > The Public Land Survey System (PLSS) is a method used in the United > States to survey and identify land parcels, particularly for titles > and deeds of rural, wild or undeveloped land. > > One of their claims is that 'The importance of the PLSS is one of the > many barriers to metrication of property title in the United States.'
I live in a metes-and-bounds state, so I don't see PLSS descriptions, except as academic exercises for questions which will be on the test. However, I don't think the PLSS is that serious a barrier to metrication. A legal description can include both township and section numbers and dimensions in meters, as well as state plane coordinates. "Distances are measured in U.S. survey miles, ...; these differ from international miles by a few millimeters." The difference is 3.2 mm in 1609 m. Using a total station, my crew achieved a misclosure of 23 mm in 460 m surveying around the Facilities Center at CPCC; this is a good misclosure in a boundary survey, the maximum allowed being 1:10000. Using chains, surveyors can, and did, make much larger errors. Should one of those township markers be found missing, the surveyor's job is to replace it where it was, not where it should have been assuming perfectly precise measuring. There is a system of horizontal control monuments placed by the NCGS, of which I know two (Wagner and Hagemeyer) on campus, one (McDowell) along the street, and one more that I have coordinates of but haven't seen myself (someone else held the rod). Any survey recorded in a map book that is within 2000 ft (610 m) of one of these monuments is required to show the bearing and distance to it. All coordinates of these monuments are calculated and published in meters. Pierre
