De Revolutionibus, Preface and Book I.

Albategni Almagest annual revolution apogee appear Arabic Aristarchus of Samos Aristotle ascribe Astronomy Averroes axis Cancer Capricorn CELESTIAL SPHERES Chorobates circle circular motion Coelo diameter Dioptra diurnal rotation Earth moves Earth's centre ecliptic Ecphantus edition equal equator five planets Fixed Stars Gerard of Cremona given by Copernicus greater Greek half the subtense heavenly bodies Heavens Hicetas Hipparchus Holiness intersection Jupiter Latin length Lysis to Hipparchus Mars mathematicians Mathematics mediaeval movement Muhammed natural nearer nearest NICOLAUS COPERNICUS numerals observe opposite orbits perigee phenomena Philolaus philosophers Plato pole printed at Venice Ptolemy Pythagorean ratio reason Regiomontanus remain at rest remaining side result follows REVOLUTIONIBUS revolves right angle rise round the centre Saturn sides containing sphere of land sphere of water spherical triangle subtense of twice Sun and Moon T. L. Heath Theorem things Timaeus translation triangle are known Venus and Mercury West to East