QUANTITATIVE MEASURES conformal projections, a b everywhere on the projection. Whena eb, the valueof 2โอม is09. Hence there is no angular deformation at points on con- formal projections. Because the values of a and b vary from place to place, however, the product of abwill alsovary from placetoplace. Consequently, all conformal transformations enlarge or reduce areas relative to one another. The product ab at various points provides an index of the degree of areal change. On equal area projections, the scale relation ships at each point are such that the product of ab always equals 1.0. Any difference between the va+ ues of a and b produces a value of 20 greater than 00. Consequently, all equakarea projectionsdefonm angles. The value of 20 at various points provides an index of the degree of angular distortion. On projections that are neither conformal nor equal area, a will not equal b. Norwill the product of ab 1.0. Therefore, on such projections, both the values of Sand2s2willvary from place to place and serve as quantitative measures of the distor. tion.