xiv Contents 



CHAPTER III. 



PAGE 



THE MIDDLE AGES (FROM ABOUT 600 A.D. TO ABOUT 



1500 A.D.), 55-69 .... 76-91 



55. The slow development of astronomy during this 



period 76 



56. The East. The formation of an astronomical school 

 at the court -of the Caliphs : revival of 

 astrology : translations from the Greek by 

 Honein ben Ishak, Ishak ben Honein, Tabit 

 ben Korra, and others 76 



57~8- The Bagdad observatory. Measurement of the 

 earth. Corrections of the astronomical data 

 of the Greeks : trepidation .... 78 



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 



6l. 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 cata- 

 logue .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 ofTivoli, 

 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 



