Machine summary:
Ibn Khallikan, the celebrated Muslim biographer,1 says, "He made astronomy his particular study, but he was well 'versed in other sciences and dis• played an eminent talent for poetry".
In his voluminous work 'Ali ibn Yfmus amply discusses the subject whereon he treats and indicates the application of the rules therein given, whilst its correctness testifies to the great care and labour with which it was compiled.
S. , in his work on " Arabic Authors", says :• " Another celebrated astronomer, 'AB ibn Yfinus, was a native of Egypt, and appears to have lived at the court of the monarch· of Egypt, Al-Hakim bi'amrillah, and under .
The following observations by 'Ali ibn Yunus, upon the influence of one of the constellations, is frequently quoted in the works of Arabian astrologers :-'' Mizan (Libra) is an equalising sign,* and, if this is the Tali', (predominating constellation), in which a person enters the world, then the Shakhs (individual) will be possessed of high powers of comparison and of good judgment, and able to take an impartial and dispassionate view of matters, and will love harmony and always strive to adjust quarrels and.
A treatise by 'Ali ibn Yfmus on the Shirayan (Sirius and Procyon-The great and little dog-stars), wherein he dwelt at considerable length on the heliacal rising of Sirius and the time of its declension, is frequently alluded to, and quotations therefrom cited by later Arabian astronomers.
'Ali ibn Yfmus was versed in a great variety of sciences and, as we have already seen, played on .