Orr, M. A. (Mary Acworth) · London and Edinburgh, Gall and Inglis · leaf 155
19 distance and consequently the brightness will constantlyvary, and Mars will be brightest when at perigee P(point nearest Earth), and faintest w^hen in apogeeA (point furthest from Earth).^ But, as the Greeks had discovered, Mars attains hisgreatest brilliance at different points of the zodiac,… … Fig. 23. The Moveable Eccentric. by making PGA turn round upon the fixed point E,so that for instance when the sun had moved througha quarter of his circle (in three months) P A had movedto PA, and the whole eccentric had moved into thenew position shown in the diagram, its centre G beingnow at C…
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.
