August epicycloidal

August

Classifications

conformal

Graticule

Meridians: Central meridian is straight. Other meridians are curved and concave toward the central meridian.
Parallels: Equator is straight. Other parallels are curved and concave toward the nearest pole.
Poles: Points.
Symmetry: About the central meridian or the equator.

Aspects

Transverse oblique aspect used by Athelstan F. Spilhaus in 1942 to show a map of world oceans.

Scale

Increases rapidly with distance from the center.

Distortion

Great distortion of area toward the 180th meridians in comparison with the center.

Other features

Boundary of the world map is a two-cusped epicycloid. Like the Eisenlohr projection, this projection has no “singular” point at which conformality fails. Unlike the Eisenlohr, the map boundary has a varying scale.

Usage

Novelty whole-world maps.

Similar projections

Eisenlohr has a boundary of constant scale.
Van der Grinten IV is not conformal and has circular arcs for meridians and parallels.

Origin

Presented by F. August and G. Bellermann in Germany in 1874.

Description adapted from J.P. Snyder and P.M. Voxland, An Album of Map Projections, U.S. Geological Survey Professional Paper 1453. United States Government Printing Office: 1989.