Classifications
pseudocylindric
Graticule
Meridians: Sinusoidal curves.
Parallels: Equally spaced straight parallel lines. Perpendicular to the central meridian.
Poles: Lines about 54% the length of the equator.
Symmetry: About the central meridian and the equator.
Distortion
Undistorted at 30°N/S (or other, depending on the standard parallel) on the central meridian. Low along equator and central meridian until higher latitudes. Distortion mix is biased toward angular deformation.
Similar projections
Eckert V is very similar but scaled smaller. Winkel I is very similar when giving it a 0° standard parallel.
Origin
Presented by Reinholds V. Putniṇš of Latvia in 1934.