90 LITERATURE OF THE ARABS. 



ing-ly 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 observ^ation. 

 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 twenty- three degrees and a half; 

 but not a single step was made towards the discov- 

 ery of the solar system beyond the hypotjiesis 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- 



