, an Arabic prince of Batan in Mesopotamia, was a celebrated astronomer, about the year 880, as appears by his observations. He is also called Muhammed ben Geber Albatani (Mahomet, the son of Geber) and Muhamedes Aractensis. He made astronomical observations at Antioch, and at Racah or Aracta, a town of Chaldea, which some authors call a town of Syria or of Mesopotamia. He is highly spoken of by Dr. Halley, as a man of great acuteness, and accuracy in making observations. Finding that the tables of Ptolemy were imperfect, he computed new ones, which were long used as the best among the Arabs: these were adapted to the meridian of Aracta or Racah. He composed in Arabic a work under the title of “The Science of the Stars,” comprizing all parts of astronomy, according to his own observations and those of Ptolemy. The original of this, which has never | been published, is in the library of the Vatican. It was translated into Latin by Plato of Tibur, and was published at Nuremberg in 1537, with some additions and demonstrations of Regiomontanus; and the same was reprinted at Bologna in 1645, with this author’s notes. Dr. Halley detected many faults in these editions. (Philos. Trans, for 1693, No. 204.) In this work Albategni gives the motion of the sun’s apogee since Ptolemy’s time; as well as the motion of the stars, which he makes one degree in seventy years. He made the longitude of the first star of Aries to be 18 2‘; and the obliquity of the ecliptic 23 35’; and upon his observations were founded the Alphonsine tables of the moon’s motion. 1


Hutton’s Mathematical Dictionary. —Vossius de Scient Math. D’Herbelot Bibl. Orient. Biog, Universelle.