Equilateral triangular map aligned on grid lines - is true to scale angle and area and mosaic of such maps can be made up into globe

摘要

The edge of the triangular map is true to scale. It is true with respect to area, and angle and it is always identical to the trend of a particular orthodrome. This means that maps of this kind, unlike plane-table sheets, can be made up into a globe. Such a map is very useful for navigational purposes because its range at the edge of the map encompasses a region with a length of approximately 381 km. With a scale of 1:500,000 it will require 8,000 of these maps to produce a perfect copy of the entire surface of the earth.