Chapter III

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

§ 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