The word mosque comes to us through the French mosquée; the Spanish equivalent is mesquita, while the Arabs call the “place of prostration”--_masjid_. The nucleus of every one is the _mihrab_ or niche in a wall, indicating the _kibleh_ or direction of the Great Mosque at Mecca, with its shrine, the Kaaba. Beside the mihrab was a pulpit, _mimbar_, for preaching, and sometimes in front of it, for the reading of the Koran, stood a _dikka_ or platform raised upon columns. Shelter for the worshippers was provided by arcades, which in the immediate vicinity of the mihrab were often enclosed with lattice work, thus forming a prayer-chamber--_maksura_. The size of the mosque was indefinitely enlarged by the addition of more arcades, surrounding usually an open court, in the centre of which, as in the atrium of the Early Christian basilicas, was a fountain for ritual ablution. The tomb was usually distinguished by a dome and during the lifetime of its founder served the purpose of a pleasure-house; corresponding somewhat to the Roman nymphæum, and, as in the case of the Taj Mahal, set in the midst of a beautiful system of gardens, water-basins, and terraces. In his house also the Muhammedan jealously guarded his domestic privacy. He followed the Romans in leaving the exterior of his house plain, while centering all its luxury and comfort around an open interior court. Special quarters were provided for the women and the seclusion of their lives within the harem led to two features which are characteristic of Oriental houses, the balcony and the screen. That the occupants might take the air, balconies were built out from the walls both of the court and the exterior; and screened with lattice work, on the designs of which great skill and beauty were expended. The palaces represented the extension of the house-plan by the addition of halls of ceremony. Sometimes, as in the case of the Alhambra, they combined the character of a citadel, and were always generously supplied with water, as well for the ablutions enjoined in the Koran, as for purposes of beauty. The Arabs, in fact, readily learned the Roman methods of engineering and hydraulics and in their houses and cities and in the irrigation of land carried the system to a high degree of perfection. The system by which learning and culture circulated throughout the Muhammedan world was illustrated in the spread of the arts of design. Persia, for example, was a centre of the ceramic art, and wherever the Muhammedan civilisation spread, the art of pottery was revived and took on new and distinctive splendour. Enamel colours of the purest tones and finest translucence were developed and the glazes were distinguished by extraordinary lustre. They were lavished not only on vessels of practical service but also on tiles for the decoration of walls.