Classifications
polyconic
Graticule
Meridians: Central meridian is straight. Other meridians are circular, equally spaced along the equator and concave toward the central meridian.
Parallels: Equator is straight. Other parallels are circular arcs, concave toward the nearest pole.
Poles: Points.
Symmetry: Along the central meridian or the equator.
Scale
True along the equator. Increases rapidly with distance from the equator.
Distortion
Great distortion of area near the poles.
Other features
The world is enclosed in a circle.
Usage
World maps by the U.S. Department of Agriculture, the U.S. Geological Survey, the National Geographic Society, and others.
Similar projections
Lagrange is conformal.
Van der Grinten 11 has parallels curved to intersect meridians at right angles.
Mercator is conformal and has straight meridians and parallels.
Origin
Presented by Alphons J. Van der Grinten (1852–?) of Chicago in 1898. U.S. Patent obtained in 1904.
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.