Claudius Ptolemy was born at Pelusium, in Ægypt, and became an illustrious disciple of the school of Alexandria, in which city he flourished during the reign of Adrian and that of Antoninus Pius. The date of his birth has been commonly assigned to the 70th year of the Christian æra; but the accuracy of this date seems questionable; for he has himself noted in one part of his works, that Antoninus reigned twenty-three years. He must have, therefore, survived that prince; and, as it is not probable that he continued his scientific labours until after ninety years of age, which he must have done had he been born about the year 70, because Antoninus died in the year 161, it seems that his birth would be more properly ascribed to some later period. Moreover, it is asserted by the Arabians, that he died in the 78th year of his age; and a similar statement is also made by Luca Gauricus, in the dedication of his version of the Almagest[7] to Dominico Palavicini: Gauricus has, however, placed his death in the year 147, which does not accord with the fact of his having survived Antoninus. Ptolemy has recorded that he observed, at Alexandria, an eclipse of the Moon, in the 9th year of Adrian; and that he made many observations upon the fixed stars in the 2nd year of Antoninus Pius: whence it may be concluded, that his observations upon the heavens were principally made during the period from A.D. 125 to A.D. 140, or thereabouts; and it also follows, of course, that the supposition, entertained by some authors, of his identity with the Ptolemy who was always in attendance upon Galba, as his personal astrologer, and who promised Otho that he should survive Nero and obtain the empire, is entirely without foundation. To Gauricus’s[8] version of the Almagest there is also another dedication, addressed to Pope Sixtus, and composed by George Trapezuntius, describing Ptolemy as “_regiâ stirpe oriundum_,” and explaining that he had, “with a truly regal mind,” applied himself to the sciences, because the ancient sceptre of the Ptolemies had previously passed into the hands of Cleopatra, and because the kingdom of Ægypt had been since reduced to the state of a Roman province. The authentic details of the circumstances of Ptolemy’s life are, however, extremely few. It is said that he was distinguished among the Greeks by the epithets “most wise,” and “most divine,” on account of his great learning; and, according to the Preface to Whalley’s translation of the Tetrabiblos, the Arabians report that “he was extremely abstemious, and rode much on horseback”; adding, that although he was “spruce in apparel,” yet his breath was not remarkable for an agreeable odour. [7] Printed at Basle, 1541. [8] Chalmer’s Biographical Dictionary.