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: About the central meridian or the equator.
Scale
True on 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. All meridians intersect parallels at right angles, but projection is not conformal. Spacing of parallels along the central meridian is the same as that for Van der Grinten I.
Usage
World maps, but rarely.
Similar projections
Lagrange is conformal.
Van der Grinten I has parallels that do not intersect meridians at right angles.
Origin
Presented by Alphons J. Van der Grinten (1852–?) of Chicago 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.