Scarcely had the Arabs become firmly settled in Spain than they commenced a brilliant career. Adopting what had become the established policy of the Commanders of the Faithful in Asia, the Emirs of Cordova distinguished themselves as patrons of learning, and set an example of refinement strongly contrasting with the condition of the native European Princes. Cordova under their administration, at the highest point of their prosperity, boasted of more than two hundred thousand houses, and more than a million inhabitants. After sunset a man might walk through it in a straight line for ten miles by the light of the public lamps. Seven hundred years after this time there was not so much as one public lamp in London. Its streets were solidly paved. In Paris, centuries subsequently, whoever stepped over his threshold on a rainy day stepped up to his ankles in mud. Other cities, as Granada, Seville, Toledo, considered themselves rivals of Cordova. The palaces of the Khalifs were magnificently decorated. Those sovereigns might well look down with supercilious contempt on the dwellings of the rulers of Germany, France, and England, which were scarcely better than stables--chimneyless, windowless, with a hole in the roof for the smoke to escape, like the wigwams of certain Indians. [Illustration: INTERIOR OF MOSQUE, CORDOVA.] About the same time the passion for learning was growing in the East. Bagdad was founded A.D. 762, and about the year 800 Haroun Al-Raschid founded the famous university of that city. Libraries and schools were established throughout the two sections of the Saracenic dominions. Greek and Latin works of philosophy and science were translated, but the licentious and blasphemous mythology of the classical poets was abhorred by this serious nation, and no Arabic versions of Olympian fables were ever made. Astronomy, mathematics, metaphysics, and the arts of agriculture, of horticulture, of architecture, of war, and of commerce, were advanced to an extent which this century does not realise, while amid all this progress the study of chemistry, medicine, and pharmacy was pursued with particular eagerness.