42 A TROPICAL DEPENDENCY colour. The use of water was thoroughly understood.

Fountains, cascades, and lakes gave coolness and moisture to the air, and also provided opportunities for the keeping of fish and the special cultivation of water-plants. Garden fruits and vegetables were cultivated in rare perfection and variety. In the gardens there were labyrinths, and marble playing-courts. There were menageries of curious animals, and aviaries of foreign birds. Botany, horticulture, zoology, and ornithology were passions no less of the learned than of the rich.

In the town of Cordova, for a distance of ten miles, the streets were lit at night by lamps placed close to one another. The descriptions of the mosques and buildings of Cordova — including the famous mosque with the 360 arches, and the even more famous palace of Azzahra, which took forty years to build, and contained the Hall of the Caliphs, roofed in pure gold, and lighted at will by fountains of quicksilver, which, when they were set in motion, caused the room **to look in an instant as if it were traversed by flashes of lightning " — are so elaborate as to fill many volumes. The size of the Azzahra palace may be imagined from the fact that it had 15,000 doors.

It had amongst its many beauties remarkable fountains and terraces of polished marble, which overhung ** matchless gardens." It was filled with works of art, and, according to one writer, it was such that '* travellers from distant lands, men of all ranks, following various religions, princes, ambassadors, merchants, pilgrims, theologians, and poets, who were conversant with edifices of this kind, and had surveyed this, all agreed that they had never seen in the course of their travels anything that could be compared to it." The other cities of the Arabs in Spain were no less remarkable. In the garden of one of the palaces of Toledo there was an artificial lake, in the centre of which there was a kiosk of stained glass adorned with gold.

" The architect so contrived this that by certain geometrical rules the water of the lake was made to ascend