Like Cordova, Palermo was divided into five separate quarters, each of which was isolated from the others when the gates were closed. The houses were of blocks of polished stone put together with the greatest accuracy, the streets were lighted, the mansions of commanding height and symmetrical proportions, the habitations of the poor more commodious than the dwellings of many of the wealthy burghers of Paris and London. In the time of Ibn-Jubair, who visited Palermo during the reign of William the Good, the costumes and the manners of the Christians were not distinguishable from those of their Moslem vassals. The ladies wore veils of different colors and garments of mingled silk and gold. Dainty slippers, embroidered in arabesques with the precious metals, protected their tiny feet, jewelled ornaments of exquisite patterns glittered upon their bosoms, and the aroma of costly essences which enveloped them revealed their passionate love of perfumes. The fusion of races was nowhere so apparent or so remarkable as in the unrestricted intimacy maintained, and in the refined courtesies reciprocated by the once hostile nationalities which composed the population of the Norman capital. The amenities of social intercourse required the practice of politeness and of self-restraint even among enemies. In the time of William the Good cruelty and rapine were stigmatized as Teutonic vices. The noble and elevating pursuits of science were not neglected under the Moors of Sicily and their intelligent and progressive conquerors, the Norman princes. Geography, astronomy, chemistry, and medicine were studied with diligence and success. Edrisi, whose descent from the royal dynasty of Fez has been obscured by the eminent reputation he attained as a geographer and a philosopher, made for Roger II. a planisphere which represented at once the surface of the earth and the positions of the heavenly bodies. From the minarets of Palermo, the Arab astronomer observed the motions of the planets, the periodical recurrence of eclipses, the relative positions and general distribution of the stars in space, by the aid of instruments invented on the Guadalquivir and the Tigris, and of tables computed on the plains of Babylon centuries before the Christian era. The Moslem thus consecrated to the prosecution of scientific research the towers of his most sacred temples, at a time when from the cathedrals of Europe doctrines were promulgated which menaced, with the severest penalties that ecclesiastical malignity could devise, every occupation which in any way contributed to the emancipation of reason or the intellectual progress of humanity. Astrology, that delusive study so flattering to the vanity of human nature, and so alluring to the imagination from the preternatural power supposed to be wielded by the charlatans who practised it, too often discredited the results of astronomical investigation; just as the vain and costly pursuit of the