ALBATEGNI

, an Arabic prince of Batan in Mesopotamia, who was a celebrated astronomer, about the year of Christ 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 os Chaldea, which some authors call a town of Syria or of Mesopotamia. He is highly spoken of by Dr. Halley, as a vir admirandi acuminis, ac in administrandis observationibus exercitatissimus.

Finding that the tables of Ptolomy 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. Albategni composed in | Arabic a work under the title of The Science of the Stars, comprising all parts of astronomy, according to his own observations and those of Ptolomy. This work, translated into Latin by Plato of Tibur, 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, N° 204.

In this work, Albategni gives the motion of the sun's apogee since Ptolomy's time, as well as the motion of the stars, which he makes 1 degree in 70 years. He made the longitude of the sirst star of Aries to be 18° 2′; and the obliquity of the ecliptic 23° 35′. And upon Albategni's observations were founded the Alphonsine tables of the moon's motions; as is observed by Nic. Muler, in the Tab. Frisicæ, pa. 248.