90 LITERATURE OF THE ARABS. 



ingly its professors, independently of all medical 

 considerations, were seen in the courts, and con- 

 sulted in the cabinets of princes ; and no public or 

 even private enterprise of moment was undertaken 

 without previously obtaining the concurrence of the 

 heavenly bodies. 



The most flourishing period of Arabian astron- 

 omy was the reign of Almamoun, who was himself 

 devoted to the study of this science. He caused a 

 complete digest of it to be composed by the most 

 eminent men of his court, and provided at his own 

 cost the necessary instruments of observation. 

 The land of the Chaldeans still supplied the same 

 spacious level, the same unclouded horizon ; and 

 under his munificent patronage the. philosophers of 

 Bagdad, first on the plains of Shinar, and a second 

 time on those of Cufa, accurately measured a de- 

 gree of the great circle of the earth, and determined 

 at 24,000 miles the entire circumference of our 

 globe. The process by which this remarkable mea- 

 surement was conducted is described by Abulfeda, 

 from the relation of Ibn Khallican and the best his- 

 torians. The obliquity of the ecliptic was calcu- 

 lated at about ^venty-three degrees and a half; 

 but not a single step was made towards the discov- 

 ery of the solar system beyond the "hypothesis of 

 Ptolemy. 



Among the Arabian astronomers were several 

 who distinguished themselves both by their writings 

 and observations. Albumazar published an Intro- 

 duction to Astronomy — a Treatise on the Conjunc- 

 tion of the Planets — and another on the Origin, De- 

 rivation, and End of the World. The celebrated 

 Alfragani composed a classical work entitled Ele- 

 ments of Astronomy, of which a translation, with 

 notes, has been given by Professor Golius, and 

 which presents a concise exposition of Ptolemy's 

 Almagest. This author likewise produced a trea- 

 tise on solar clocks, and on the astrolabe. Moham- 



