ALMAMON, Caliph of Bagdat, a phi losopher and astronomer in the beginning of the ninth century, he having ascended the throne in the year 814. Ile was son of Harun AI-Hanel:id, and grandson of A Imansor. Having been educated with great care, and with a love for the liberal sciences, he applied himself to cultivate and encourage them in his own country. For this purpose lie requested, the Greek emperors to supply him with such hooks of philosophy as they had among them ; and he collected skilful interpreters to translate them into the Arabic language. He also encouraged his subjects to study them ; frequenting the meetings of the learned, and assisting at their exercises and deliberations. Ile formed a college at Khorasan, and selected to preside over it Mesul of Damascus, a famous Christian physician. When his father, who was still living, remonstrated against the ap pointment, on account of the president's religion, he replied, that he had chosen him, not as a teacher of theology, but for the instruction of his subjects in science anti the'useful arts, and that his father well knew, that the most learned men and skilful artists in his dominions were Jews :uld Christians. Ile causedPtolemy's Almagest to be translated in 827, by Isaac Ben-lionain, and Thabet 13en-korah, ac cording to Herbelot, but according to others, by Sergius, and Alhazen, the son of Joseph. In his reign, and doubtless by his encouragement, an astronomer of Bagdat, named Habash, composed three sets of astronomical tables.
' Almamon himself made many astrono mical observations, and determined the obliquity of the ecliptic to be then 23° 35', or 23° 33' in some manuscripts, but Vossius says 23° 51', or 23° 34'. Ile also caused skilful observers to procure pro per instruments to be made, and to exer cise themselves in astronomical observa tions ; which they did accordingly at She maxi in the province of Bagdat, and upon Mount Casius, near Dania& Under the auspices of Manion, also, a degree of the meridian was measured on the plains of Sinjar, or Sindgiar, upon the borders of the Red Sea; by which the degree was found to contain 56 2.3 miles, of 4000 coudees each, the coudee being a foot and a half : but it is not knot% n what foot is here meant, whether the Roman, the Alexandrian, or some other. Albufecla says that this cubit con tained 27 inches, each inch being deter mined by six grains of barley placed side ways; but Thevenot says, that 144 grains of barley, placed in this manner, would give a length equal to Paris foot : four cubits would be equal to one toise and nine inches, and therefore 4009 cu bits, that is, 56 2-3 miles, would give 63,730 toises. But if the ordinary cubit
of 24 inches was the measure to which the calculation is to be referred, the de gree, in this estimate of' it, would con tain 56,666 toises. According to another valuation of a cubit, this measure would consist of 53,123 French toises.
Almamon was a liberal and zealous en courager of science, in consequence of which the Saracens began to acquire a degree of civilization and refinement, to which they had formerly been strangers. The liberality of his mind obtained for Ahnamon the reputation of infidelity. But, whatever opinions he might hold re specting the Koran,he seems to have had a confidence and trust in the Supreme Being. In this work we shall not follow the Caliph into the field of battle, nor re cord his victories, which were brilliant and important. We must look to him in the character of a philosopher and man of science, and, in addition to what has already been noticed, we may remark, that he built a new nilometer, for mea. swing the increase of the Nile, and re paired one that was gone to decay. In the year 833, as he was returning from one of his expeditions, he unwarilv quenched his thirst, while very muck heated by exercise, with cold water, which brought 031 a disorder that termi nated his life. Outing his last illness, he settled the affairs of the state, and then exclaiming, in the spirit of piety, " 0 thou who never diest, have mercy on me, a dying mrm." He expired at the age of 49, after a reign of 20 years. Ile was in terred at Tarsus. To the principles of science, and not to those of the Moham medan religion, have been ascribed the liberality and benignity- of temper, which he displayed in certain trying circum. stances. When his uncle and rival Ibra him was taken, brotight to trial, and con denmed, the caliph, instead of sanction ing the sentence, tenderly embraced his relation, saying, "Uncle, be of good cheer, I will do you no injury:" and he not only pardoned him, but granted him a rank and fortune suitable to his birth. Being complimented on acconnt of this generous cleed, he exclaimed, "Did but men know the pleasure that I feel in par.
ttoning, all who have offended me Would come and confess their faults." Alma mon, in the course of his reign, employed the most skilful astronomers that he could find, to compose a body of astrono mical science, which still subsists among oriental MSS. entitled " Astronomia ela borata a.compluribus D. D. jussu regis Maimon."