ब्राह्मस्फुटसिद्धान्त (ब्रह्मगुप्त - शून्य, कुट्टक, बीजगणित एवं सम्पूर्ण २१ अध्याय सान्वय सटीक)

WESTERN COUNTRIES UNDER ISLAM 13
make the contents of Ptolemy's work accessible to the less
learned. In the nineteenth century this book gave rise to a
long controversy, which we shall presently consider somewhat in
detail.
Western Countries under Islam
In the eleventh and twelfth centuries we do not find any
names of conspicuous astronomers in Muhammedan Asia.
But the western countries under Islam had in the meantime
become ready to do their share of the work of keeping the
mathematical sciences alive. In the Fatimite kingdom of
Egypt Ali ben Abi Said Abderrahman ben Ahmed ben Junis,
generally called Ibn Junis (died 1009), was distinguished both as
an astronomer and a poet. At Cairo a liberally equipped
observatory enabled him to verify the planetary theories which
had once been developed in the neighbouring Alexandria, and
in token of his gratitude to the reigning sovereign, Al Hakim,
he named his work the Hakemite Tables.¹ We have to pass to
the farthest west to find the next astronomer of mark in the
person of Ibrahim Abu Ishak, known as Al Zarkali (in Europe
afterwards called Arzachel). He was a native of Cordova, lived
about 1029-1087, and edited planetary tables called the Toledo
Tables.² In the following century we find two celebrated
astronomers of Seville, Gabir ben Aflah, known as Geber (died
1145, often mistaken for the great alchemist, Gabir ben
Haijan, in the eighth century),³ and Nur ed-din al Betrugi
(Alpetragius), both of whom raised objections to the
planetary theories of Ptolemy, though they failed to produce
anything better of their own. Spanish astronomy continued
to flourish for a while, although the power of the Arabs in the
Peninsula was rapidly declining, and it produced in the thirteenth
century a very remarkable man, who, although a Christian
king, must be included in this account of Arabian astronomy,

1. Caussin has published an extract in vol. vii of the Notices et Extraits des
   manuscrits (Le livre de la grande table Hakemite). Other Chapters, trans-
   lated by the elder Sedillot but never published, are reviewed by Delambre,
   Hist. de l'astr. du Moyen Age, p. 95 sqq.
2. Never published. Delambre, l. c. p 176, and Steinschneider, Etudes sur
   Zarkali, Bullettino Boncompagni T. xx. p. 1.
   3 The word algebra has also sometimes erroneously been connected with his
   name.