Gall's stereographic was designed around 1855. It is a cylindrical projection with two standard parallels at latitudes 45° N and S.
A cylindrical stereographic projection based on two standard parallels at 45° N and S. The globe is projected perspectively onto a secant cylinder from the point on the equator opposite a given meridian. Meridians are equally spaced straight lines. Parallels are straight lines with spacing increasing away from the equator. Poles are straight lines.
Lines of contact
Two lines at 45° N and S.
All meridians and parallels.
Shapes are true at latitudes 45° N and S. Distortion slowly increases away from these latitudes and becomes severe at the poles.
Area is true at latitudes 45° N and S. Distortion slowly increases away from these latitudes and becomes severe at the poles.
Locally correct at latitudes 45° N and S. Generally distorted elsewhere.
Scale is true in all directions along latitudes 45° N and S. Scale is constant along parallels and is symmetrical around the equator. Distances are compressed between latitudes 45° N and S and expanded beyond them.
Used only for world maps.
Uses and applications
Used for world maps in British atlases.
- False Easting
- False Northing
- Central Meridian
- Longitude of Central Meridian