The World on Mercator's Projection by TANNER, H.[enry] S.[chenck] (1786-1858) - 1823

Philadelphia: H. S. Tanner, 1823. Copper-engraved map, with full original color, n very good condition. A World map by one of America's first great cartographers The objective of depicting a three dimensional sphere on a two dimensional sheet of paper has challenged mapmakers since Classical times. Mercator's solution was to straighten all of the longitudinal meridians, making them perpendicular to the lines of latitude. The consequence of this projection was that while lands close to the Equator assumed a relatively realistic form, lands closer to the poles attained a progressively attenuated and exaggeratedly large appearance. The map reflects the great improvements in geographical understanding in the wake of the epic sea voyages of the late eighteenth-century, most notably those by Cook, La Perouse and Vancouver.