§ 59. _Albategnius_: discovery of the motion of the sun’s apogee 79
§ 60. _Abul Wafa_: supposed discovery of the _variation_ of the moon. _Ibn Yunos_: the _Hakemite Tables_ 79
§ 61. Development of astronomy in the Mahometan dominions in Morocco and Spain: _Arzachel_: the _Toletan Tables_ 80
§ 62. _Nassir Eddin_ and his school: _Ilkhanic Tables_: more accurate value of precession 81
§ 63. Tartar astronomy: _Ulugh Begh_: his star catalogue 82
§ 64. Estimate of oriental astronomy of this period: Arabic numerals: survivals of Arabic names of stars and astronomical terms: _nadir_ 82
§ 65. =The West.= General stagnation after the fall of the Roman Empire: _Bede_. Revival of learning at the court of Charlemagne: _Alcuin_ 83
§ 66. Influence of Mahometan learning: _Gerbert_: translations from the Arabic: _Plato of Tivoli_, _Athelard of Bath_, _Gherardo of Cremona_. _Alfonso X._ and his school: the _Alfonsine Tables_ and the _Libros del Saber_ 84
§ 67. The schoolmen of the thirteenth century, _Albertus Magnus_, _Cecco d’Ascoli_, _Roger Bacon_. _Sacrobosco’s Sphaera Mundi_ 85
§ 68. _Purbach_ and _Regiomontanus_: influence of the original Greek authors: the Nürnberg school: _Walther_: employment of printing: conflict between the views of Aristotle and of Ptolemy: the celestial spheres of the Middle Ages: the _firmament_ and the _primum mobile_ 86
§ 69. _Lionardo da Vinci_: _earthshine_. _Fracastor_ and _Apian_: observations of comets. _Nonius._ _Fernel’s_ measurement of the earth 90
COPPERNICUS (FROM 1473 A.D. TO 1543 A.D.), §§ 70-92 92-124
§§ 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
§ 83. End of first book. _The second book_: decrease in the obliquity of the ecliptic: the star catalogue 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