摘要 : An assessment is made of the accuracy of the map and written survey, which is essentially a list of land-holders and theareas held by each, and of their mutual consistency. The geometry of the map is compared quantitatively with t... 展开 An assessment is made of the accuracy of the map and written survey, which is essentially a list of land-holders and theareas held by each, and of their mutual consistency. The geometry of the map is compared quantitatively with that of thefirst edition ( 1852 ) Ordnance Survey 6-inch ( 1 : 10 560) map. The Saxton map is found to have a scale of 1: 5140,leading to the conclusion that the perch used in the scale bar represents 71/9 yards or thereabouts. The areas quoted in thewritten survey are consistent with acres based on this value. The positional accuracy of points on the map is found to be 20 m, and areas of typical plots determined from the map are uncertain by between about 4 and 12%. The relationshipbetween these two facts can be understood through a detailed study of the statistics of the errors in separations of points onthe map. The written survey is found to omit a substantial number of plots of land from its listings. The map thus appearsto be more reliable overall than the written survey. 收起