The Mercator projection is a modification of a standard cylindrical projection, a technique used by cartographers to transfer the spherical proportions of the earth to the flat surface of a map. For correct proportions, the parallels, or lines of latitude, are spaced at increasing distances toward the poles, resulting in severe exaggeration of size in the polar regions. Greenland, for example, appears five times larger than it actually is. Created by Flemish cartographer Gerardus Mercator (1512–1594) in 1569, this projection is useful primarily because compass directions appear as straight lines, making it ideal for navigation.