Craster parabolic

Putniṇš P4

Classifications

pseudocylindric
equal-area

Graticule

Meridians: Central meridian is a straight line half as long as the equator. Other meridians are equally spaced parabolas intersecting at the poles and concave toward the central meridian.
Parallels: Unequally spaced straight parallel lines, farthest apart near the equator; spacing changes very gradually. Perpendicular to the central meridian.
Poles: Points.
Symmetry: About the central meridian or the equator.

Aspects

Oblique aspect used for map of Asia by National Geographic Society.

Scale

True along latitudes 36°46′N and S. Constant along any given latitude; same for the latitude of opposite sign.

Distortion

Distortion is severe near outer meridians at high latitudes but somewhat less than that of the sinusoidal projection. Can be substantially reduced by interruption. Free of distortion only at latitudes 36°46′N and S. At the central meridian.

Usage

Thematic world maps in textbooks.

Similar projections

Several pseudocylindrics, such as the sinusoidal and the Boggs eumorphic.
Putnins P3 projection (1934) has meridians, poles, and equator identical to those of the Craster, but parallels are equally spaced.

Origin

Presented by John Evelyn Edmund Craster (1873-?) of England in 1929. Developed further by Charles H. Deetz and O.S. Adams in 1934.

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.