Note 169 — Chapter I · THE CONTRIBUTION OF THE ANCIENT WORLD
Reading edition
These were the invention of Hipparchus (Avezac, Projection, 1863, pp. 16–20). The stereographic projection, called planisphere, was described by Ptolemy in a treatise entitled Planisphere which was translated into Latin from the Arabic during the time of the Crusades. See below, p. 398, note 36.