for defence had been improved by the ingenuity and the resources of many successive dynasties. Long anterior to the Punic occupation it had been the seat of power. Its formidable situation had awakened the astonishment of the Romans in the days of Pliny. The Visigoths had rebuilt its walls and made it their capital, a distinction it maintained over the charming Andalusian cities while that domination endured. The Saracens had strengthened the fortifications and embellished the suburbs with magnificent villas, pleasure-grounds, and gardens. Under the rule of the Beni-Dhinun, Toledo contained a larger and more thrifty population than it had ever before possessed. Encircled, except on the north, by the waters of the Tagus, the foundations of its walls stood more than a hundred feet above the level of that rapid stream. An inaccessible precipice insured it against a hostile attack from the direction of the river, while upon the land side the great height and enormous solidity of the walls and towers might well defy the efforts of a besieging army provided only with the imperfect military appliances of antiquity. The political influence and extensive trade enjoyed by the city of Toledo as the capital of one of the great Moorish principalities were eclipsed by the splendor displayed by its emirs in the royal residences which were scattered through its environs. One of the most remarkable of these was called, in the picturesque imagery of the Arabic tongue, The Mansion of the Hours. It stood on the bank of the Tagus a short distance west of the city, and was decorated with all the magnificence and ingenuity of Moorish art. Its walls sparkled with mosaics and gilded stuccoes. In its construction the rarest marbles were used with lavish profusion. Fountains of exquisite proportions cooled its halls and court-yards. In the largest of these was placed one of the most curious pieces of hydraulic mechanism ever invented. It was a clepsydra contrived by the famous astronomer Al-Zarkal, and consisted of two basins or reservoirs supplied with water, whose quantity was regulated exactly according to the phases of the moon. With the appearance of the crescent on the horizon the water commenced to run into the reservoirs, which it continued to do until the fourteenth day, when they were filled, and then it gradually diminished in quantity until the twenty-ninth day, when they were entirely empty. If at any time water was added to or taken from these basins the amount was not affected; the concealed mechanism, acting automatically, at once removed the surplus or supplied the deficiency. The movement of the water was accurately calculated according to the constantly varying inequality of the days and nights,--at sunrise on the first day a twenty-eighth part, and at sunset a fourteenth part, appeared. The inventive genius requisite for the construction of a mechanism capable of producing such extraordinary results may be readily imagined, if not appreciated,