By Rectangular SystemIn the early days (from 1785) of the United States,provisions were made to subdivide territorial landsinto townships and sections thereof, along linesrunning with the cardinal directions of north-south,east-west. Later, as additional lands were added to thepublic domain, such lands were subdivided in asimilar manner.However, these methods of subdividing lands donot apply in the eastern seaboard (original 13 states)and in Hawaii, Kentucky, Tennessee, Texas, and WestVirginia. For laws regulating the subdivision of publiclands and the recommended surveying methods, checkthe instruction manual published by the Bureau ofLand Management, Washington, D.C.By Plane CoordinatesFor many years the triangulation and traversemonuments of various domestic and foreign surveyagencies have been defined by their geographicpositions; that is, by their latitudes and longitudes.Property corners might be definitely fixed in positionin the same way. The necessary computations areinvolved, and too few land surveyors are sufficientlywell versed in the theory of geodetic surveying for thismethod to attain widespread use. In recent years, planecoordinate systems have been developed and used inmany states and in many foreign countries. These gridsystems involve relatively simple calculations, andtheir use in describing parcels of land is increasing.Every state in the American Union is now covered bya statewide coordinate system commonly called a gridsystem.As with any plane-rectangular coordinate system,a projection employed in establishing a statecoordinate system may be represented by two sets ofparallel straight lines, intersecting at right angles. Thenetwork thus formed is the grid. A system of linesrepresenting geographic parallels and meridians on amap projection is termed graticule. One set of theselines is parallel to the plane of a meridian passingapproximately through the center of the area shown onthe grid, and the grid line corresponding to thatmeridian is the Y-axis of the grid. The Y- axis is alsotermed the central meridian of the grid. Forming rightangles with the Y- axis and to the south of the areashown on the grid is the X-axis. The point ofintersection of these axes is the origin of coordinates.The position of a point represented on the grid can bedefined by stating two distances, termed coordinates.One of these distances, known as the X-coordinate,gives the position in an east- and -west direction. Theother distance, known as the Y-coordinate, gives theposition in a north- and- south direction; thiscoordinate is always positive. The X -coordinatesincrease in size, numerically, from west to east; theY -coordinates increase in size from south to north. AllX -coordinates in an area represented on a state grid aremade positive by assigning the origin of thecoordinates: X = 0 plus a large constant. For any point,then, the X -coordinate equals the value of X adoptedfor the origin, plus or minus the distance (X´) of thepoint east or west from the central meridian (Y -axis);and the Y -coordinate equals the perpendiculardistance to the point from the X -axis. The linear unitof the state coordinate systems is the foot of 12 inchesdefined by the equivalence: 1 international meter= 39.37 inches exactly.The linear distance between two points on a statecoordinate system, as obtained by computation orscaled from the grid, is termed the grid length of theline correcting those points. The angle between a lineon the grid and the Y -axis, reckoned clockwise fromthe south through 360°, is the grid azimuth of the line.The computations involved in obtaining a grid lengthand a grid azimuth from grid coordinates areperformed by means of the formulas of planetrigonometry.A property description by metes and bounds mightinclude points located by coordinates as follows:“Commencing at U.S. Coast andGeodetic Survey Monument ‘Bradley,Va’, having coordinates y = 75,647.13 ftand x = 35,277.48 ft, as based on theVirginia Coordinate System, NorthZone, as are all the coordinates, bearings,and distances in this description; thenceS 36°30´E, 101.21 ft to the intersec-tion of Able Street and Baker Avenue,whose coordinates are y = 75,565.77 ftand x = 35,337.45 ft, . . . .”By Blocks, Tracts, or SubdivisionsIn many counties and municipalities the land ofthe community is divided into subdivisions calledblocks, tracts, or subdivisions. Each of thesesubdivisions is further subdivided into lots. Blocksand tracts usually have numbers, while a subdivisionusually has a name. Each lot within a block, tract, orsubdivision usually has a number.10-32