In consequence of these arrangements, Pompeii was well supplied with water. There were flowing jets in all houses except the poorest, and in some the amount used must have been large. In the house of the Vettii there were no less than sixteen jets, in the house of the Silver Wedding, seven; and an equally generous distribution is found in many other of the more extensive private establishments. Large quantities of water were used also in the public baths. The water pipes were made of sheet lead folded together, a transverse section showing the shape of a pear. They were of all sizes, according to the pressure; the flow of water was regulated by means of stopcocks, much like those in use to-day. Across the street from the Baths near the Forum, on the west, is a deep reservoir, of which we give the plan (Fig. 104). It is built partly below the level of the sidewalk, and measures about 50 feet in length and 13 in width, being covered by a vault. In the south end is a window (_c_), reached from one of the stairways; when the reservoir was filled to the bottom of the window, it contained not far from ninety-five thousand gallons. There were two outlets. One was at the level of the floor, closed by means of a bronze slide; the grooves in which the slide worked are preserved. This must have been used only when the reservoir was cleaned. The other outlet was placed about three feet above the floor, so that the water could be drawn off without disturbing the bottom. On the flat roof were rooms the arrangement of which cannot be determined. Similar reservoirs are found in Constantinople, designed to furnish a supply of water in case of siege. Such may have been the purpose of our structure, which seems to have been built in the early years of the Roman colony. The residents, remembering the hardships of the siege of Sulla, may have thought it necessary to make provision against a similar strait in the future. [Illustration: Fig. 104.--Plan of reservoir, west of the Baths near the Forum. _a_, _b_, _c_. Windows. _d_, _e_. Stairs.] The source from which the city received its water supply has not been discovered. Evidently it did not draw upon the sources of the Sarno; the water channel constructed by Fontana (p. 25) runs through the city at a height of less than sixty feet above the level of the sea, while the ancient aqueduct that supplied Pompeii had so great a head that in the highest parts of the city, more than 130 feet above the sea, it forced the water to the top of the water towers, at least twenty feet more. Copious springs can never have existed on the sides of Vesuvius; water must have been brought to the city from the more distant mountains bounding the Campanian plain on the east.