Almagest. Claudius Prolemaus was a celebrated mathematician, astronomer, and geographer. Of the details of his life nothing appears to be known beyond the facts that he was certainly at Alexandria in A.D. 139, and since he survived Antoninus Pius he was alive later that March, 161. His Geography, is very famous, but perhaps even more celebrated was the , usually known by its Arabic name of Almagest. Since the Tetrabiblus, the work on astrology, was also entitled , the Arabs, to distinguish between the two, called the greater work , and afterwards ; the title Almagest is a compound of this last adjective and the Arabic articels. The work is divided into thirteen books, of which VII and VIII are the most interesting to the modern astronomer, as they give a catalogue of the stars. The best edition of the Almagest is considered to be that by Halma, Paris, 1813-16, two vols., 4to.