An Historical Account of the Origin and Progress of Astronomy: With Plates

according Almagest ancient angle apogeum appear apsides Arabians ascertained ascribed assigned astronomer attraction axis Bailly cause celestial bodies centre Chaldeans Christ circle circumference coincide comets commencement computed conjunction consequently considered constellation Copernicus degrees described determined diameter direction earth eccentric ecliptic Egyptians elements epicycle epoch equal equator equinoctial points equinox Eudoxus fixed stars formed former gnomon Greeks heavens heliacal heliacal rising Hindus Hipparchus horizon hypothesis inequalities inferior planets instruments interval Jupiter Kepler known latitude latter length longitude luminary lunar mean distance mean motion mentioned Mercury meridian moon's movements nearly Newton nodes obliquity observations obtained opinion orbit parallax period phenomena philosopher planetary planets Plutarch pole precession probably Ptolemy radius respect retrograde revolution revolve right ascension rising Saturn shew shewn sidereal solar solstice sphere sun and moon sun's superior planets supposed surface theory tion Tycho Brahe variations velocity Venus vernal equinox zodiac