diameter than those of the others, as appears by the parts at present in existence ; and Delorme thinks that the emitting reservoir was like the receiving tanks, which are seen near the wall of the city of Lyons, and conducted the water by an aqueduct to the reservoir, now called the Maison Angclique, This reservoir was also furnished with the usual opening. The emitting reservoirs had an opening at a height of four and a half feet above the level of the pavement, to turn, if required, the flowing water to the bottom of the tower, and to facilitate their cleanings and reparations. The great reservoir of the Maison Angelique, the bottom of which is now buried in the ground, was supported by a series of vaults, separated by partition walls two and a half feet thick. Five of these vaults are still entire. They are semi-circular, built of small, rough, square stones, with courses of bricks in the voussoirs, in each ten and a half inches, and they appear to have been laid without mortar. A fall, or step, of one and a half foot, arched to a height of four feet, is still seen in a wall seven and a half feet thick. The water here descended by a well, or tank, one and a half foot square, which joins the south side, where it has a thickness of more than ten feet. Decolonia (in his Histoire Litteraire de la ville de Lyons,) says, that thirty leaden pipes, of from 15 to 20 feet in length, marked by the initials, TI. CLA. CAES. (Tiberius Claudius Caesar,) were found in this part. He had no knowledge of the reservoir discovered by Delorme, to which it is probable these pipes belonged, and in which they were used for distributing the water to the buildings and gardens of the palace of the Emperor Claudius. The aqueduct of Metz is another of the great works of the Romans, though of what precise date seems uncertain — possibly of the period when the legions of Caesar held possession of Gaul. The water which it conducted into the town was taken from the valley above Gorze — distant about 23 miles — now called Les Bouillons. The construc- tion of the work was essentially similar to those already described. It was in its whole length a close conduit of masonry, and carried over valleys by lofty arcades, no recourse being had to syphons or leaden pipes. 40 PRELIMINARY ESSAY. Spain, too, yet preserves some splendid aqueducts of Roman origin. That at Se- govia— the most remarkable — has an arcade of 159 arches, 94 feet high, and extending across a valley 700 yards in width. This work is ascribed to Trajan.* Upon a level at its origin with the rivulet it receives, and supported at first by a single range of arches not more than three feet high, it proceeds to the summit of a hill at the other extremity of the city, and gradually increases its height in proportion to the declivity of the ground. In its highest part a bridge has been thrown across an abyss. It has two branches which form an obtuse angle with the city. At the com- mencement of the angle it becomes a grand object. Its two rows of arcades rise majes- tically above each other, and the spectator is surprised at its gigantic height, and the lightness of its piers. It has stood 1600 years. Nor can we pass by the extensive works at Grenada, though of comparatively modern date, for supplying, with Arabian magnificence, the waters of the various baths, fountains, and apartments of the famed Alhambra. The Square of Cisterns encloses numerous reservoirs, kept constantly filled with water by an aqueduct from a neighboring hill, distant two or three miles. The largest of these reservoirs or cisterns, is 102 feet long and 56 wide, enclosed by a wall six feet thick, and protected by an arch forty-seven and a half feet high in the centre. There are two openings, or ventilators, to this cistern, three and a half feet in diameter, and carried up several feet above the surface, for the admission of air and light. From these cisterns the water was distributed as desired. The grand fountain in the Court of the Lions was thus fed. The fountain was in the centre of this magnificent O court. Twelve lions support on their backs an alabaster basin, richly decorated, elevated above which was a smaller basin. A great volume of water rose through pipes into the upper basin, which fell into that below, and was thence conducted through the mouth of the lions, to a black marble reservoir, from which, as a fountain head, the water was distri- buted in marble channels to