Bonne Projection

 

A pseudoconical, equal-area projection. Central meridian is a straight line. All other meridians are complex curves.

 

Scale

 

Scale is true along the central meridian and along all parallels.

 

Distortion

 

No distortion along the central meridian and along the standard parallel.

 

Usage

 

Used for atlas maps of continents and for topographic mapping of some countries.

 

Limitations

 

Use only for a single hemisphere.

 

Origin

 

Used considerably by Rigobert Bonne (1727-1795) in the mid-18th century, but developed by others during the early 16th century.

 

Limiting Forms

 

The Sinusoidal projection is the Equatorial limiting form of the Bonne projection. The polar limiting form is a cordiform (heart-shaped) world map devised by Johannes Stabius and used widely by Johannes Werner in about 1514 and is known as the Werner projection. The Werner projection was used by Mercator and Ortelius in the late 16th century for maps of Asia and Africa. The Bonne projection has less distortion because its projection center is at the center of the region being mapped instead of at the pole.