Chapter IV: Coppernicus (from 1473 A.d. to 1543 A.d.), §§ 70-92 92-124

§ 70. The Revival of Learning 92

§§ 71-4. Life of _Coppernicus_: growth of his ideas: publication
of the _Commentariolus_: _Rheticus_ and the
_Prima Narratio_: publication of the _De Revolutionibus_ 93

§ 75. The central idea in the work of Coppernicus:
relation to earlier writers 99

§§ 76-9. The =De Revolutionibus=. _The first book_: the
postulates: the principle of _relative motion_,
with applications to the apparent annual
motion of the sun, and to the daily motion
of the celestial sphere 100

§ 80. The two motions of the earth: answers to
objections 105

§ 81. The motion of the planets 106

§ 82. The seasons 108

§ 83. End of first book. _The second book_: decrease
in the obliquity of the ecliptic: the star
catalogue 110

§ 84. _The third book_: precession 110

§ 85. _The third book_: the annual motion of the earth:
_aphelion_ and _perihelion_. _The fourth book_:
theory of the moon: distances of the sun
and moon: eclipses 111

§§ 86-7. The _fifth_ and _sixth_ books: theory of the planets:
_synodic_ and _sidereal periods_ 112

§ 88. Explanation of the stationary points 118

§§ 89-90. Detailed theory of the planets: defects of the
theory 121

§ 91. Coppernicus’s use of epicycles 122

§ 92. A difficulty in his system 123