General

Used almost exclusively for large-scale mapping in the United States until the 1950s. Now nearly obsolete and no longer used by USGS for new plotting in its Topographic Map series.

Best suited to areas with a north-south orientation.

A compromise of many properties.

Not conformal, perspective, or equal area.

Directions

True only along the central meridian.

Distances

True only along each parallel and along the central meridian.

Areas

True only along the central meridian. Distortion increases away from the central meridian.

Shapes

True only along the central meridian. Distortion increases away from the central meridian.

Type

Conic.

Mathematically based on an infinite number of cones tangent to an infinite number of parallels

History

Thought to have originated around 1820 by Hasslet.

Note

Directly supported.

(United States Geological Survey, n.d.)