Astronomy, the science of a pastoral people, and eminently so in regions with an almost cloudless sky, like the East, was studied with great eagerness by Arabian philosophers. Almamoun, who has been before mentioned, was ardently devoted to it: at his cost the necessary instruments of observation were provided, and a complete digest of the science was made. The land where, many ages before, this science had been successfully studied by the Chaldeans, was in his power, and upon its ample plains a degree of the earth's circle was repeatedly measured, so as to determine the whole circumference of the globe to be twenty-four thousand miles. The obliquity of the ecliptic they settled at twenty-three degrees and a half: the annual movement of the equinoxes and the duration of the tropical year were brought to within a very little of the exact observations of modern times, the slight error they admitted resulting from the preference they gave to the system of Ptolemy. Albathani, or, as his name has been Latinized, Albatenius, in the ninth century, after continuing his observations for forty years, drew up tables, known as the Sabean tables, which, though not now in very high repute because of more accurate calculations, {260} were for a long time justly esteemed. Other Arabian astronomers have rendered considerable service to this science. Mohammedanism did not, like ancient paganism, adore the stars; but its disciples studied them with a diligence, without which, perhaps, Newton, Flamstead, and Halley had observed and calculated almost in vain.