Mercator, Gerardus (1512-1594)

Flemish mapmaker who devised Mercator's projection in which the parallels and meridians on maps are drawn uniformly at 90°. The projection continues to be used, in particular for navigational charts, because compass courses can be drawn as straight lines, but the true area of countries is increasingly distorted the further north or south they are from the Equator. For other types, see map projection.