Guyou

Classifications

tessellating
conformal

Graticule

Meridians: Central meridian is straight. The 90th meridians are straight but bent at the 45th parallelsN/S Other meridians are complex curves.
Parallels: Equator is straight. Other parallels are complex curves. Poles: Points, in the midpoint of opposite sides of a square bounding a hemisphere.
Symmetry: About the central meridian or the equator.

Aspects

A transverse aspect is the Peirce Quincuncial projection. An oblique aspect is the Adams projection of a hemisphere in a square.

Scale

Varies considerably along each meridian and parallel.

Distortion

Great distortion of area, especially near the 90th meridian at latitudes 45°N. Or S., where conformality fails.

Other features

Shows hemisphere conformally in a square and the world in a 2x1 rectangle. Hemispheres can be mosaicked to form a continuous map indefinitely.

Usage

Novelty map of a hemisphere or of the world.

Similar projections

Listed under Aspects above.

Origin

Presented by Emile Guyou of France in 1887.

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.