Orr, M. A. (Mary Acworth) · London and Edinburgh, Gall and Inglis · leaf 186
edher direction, but simply increased and retarded hermotion alternately during her monthly revolution.Thus, when the moon was at M, in what Ptolemy called 148 PTOLEMY. the upper apsis (or arc) of her epicycle, or as we shouldsay in her apogee, the motion on the epicycle was con-trary to her motion… … Fig. 34. The moons epicycle and deferent. near the lower apsis, or perigee, and the motion on theeccentric seemed to be accelerated. The slight difference in speed between the two motionsaccounted for the continuous displacement of the apogeein the zodiac, as may be seen from the diagram.…
Dante Alighieri, 1265-1321 · Astronomy, Ancient · Astronomy, Medieval · Early maps
Internet Archive · Wellesley College Library · Public Domain Mark 1.0. Free to use for anything.
