Behrmann equal-area

Classifications

cylindric
equal-area

Graticule

Meridians: Equally spaced straight parallel lines 0.42 as long as the equator.
Parallels: Unequally spaced straight lines, farthest apart near the equator, perpendicular to meridians.
Poles: Straight lines equal in length to the equator.
Symmetry: About any meridian or the equator.

Scale

True along latitudes 30°N and S. Too small along the equator but too large at the equator along meridians.
Increases with distance from the equator in the direction of parallels and decreases in the direction of meridians to maintain equal-area.
Same scale at the parallel of opposite sign.

Other features

Same as the Lambert cylindric equal-area projection except for horizontal compression and vertical expansion to achieve no distortion at latitudes 30°N and S. Instead of at the equator.
Equivalent to a projection of the globe using parallel lines of projection onto a cylinder secant at 30°N and S.

Similar projections

Lambert cylindric equal-area by Johann Heinrich Lambert in 1772 (Standard parallel: Equator).
Gall Orthographic by James Gall in 1855 (Standard parallels: 45°N and S.).
Trystan Edwards in 1953 (Standard parallels 37°24′N and S.).
Peters by Arno Peters in 1967 (Standard parallels: Approximately 45°N and S., thus essentially identical with the Gall Orthographic).

Origin

Presented by Walter Behrmann (1882-1955) of Berlin in 1910.

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.