the cost of a canal or series of pipes, we should be compelled to raise it again, by the expensive agency of steam or some other costly apparatus. The frequent exposure of the water to air and light at the summit of these sooterays, is another very important advantage which cannot be too strongly insisted upon ; as it is now well known that nothing tends more to purify water, than the presence of these two agents. The arrangement, likewise, of the basins on the top of the pillars, is well adapted for getting rid of much of the matters deposited from turbid waters. Lastly, to the descending pipe a small cock is attached near the ground, by which the flocks and herds of the adjoining villages and fields, are furnished at all times with a copious supply of water. " On the heights of Pera there is a large reservoir, 200 feet square, built of the most solid and substantial masonry ; from this reservoir the water is distributed through the suburbs of Fundukli, Pera, Galata, and Cassim Pacha. " After a deliberate survey of the various hydraulic contrivances for supplying Con- stantinople with water, one is at a loss to know which to admire most, the native good sense which pointed out the necessity and importance of furnishing the capital and its suburbs with pure and wholesome water, the ingenuity displayed in conquering almost invincible obstacles, or that wise and liberal economy which considered no expense too enormous, no sacrifices too great, in comparison with the health and comfort of the people. PRELIMINARY ESSAY. 45 The various water-courses about Constantinople must exceed fifty miles in length, and the expenses of the various reservoirs and aqueducts could not have been less than fifty millions of dollars." In addition to its aqueducts the ancient city used water gathered into enormous sub- terranean cisterns, which still exist, and in some instances are yet supplied with water. In Gyllius's Antiquities of Constantinople, the exploration of one of these vast ancient cisterns, of which the construction is ascribed to Constantine the Great, is thus related : " The whole ground was built upon, and made it less suspected that there was a cistern there. The people had not any notion of its existence, although they daily drew their water out of wells that were sunk into it. I went by chance into a house from which there was a descent into a cistern, and embarked in a little skiff on its waters. The master of the house having lighted torches, rowed us to and fro between the pillars, which lay very deep in the water. He was very intent upon catching fish, with which the cistern abounds, and speared some of them by the light of the torches. A faint light descends from the mouths of the wells, and is reflected upon the water, and here the fish usually go for air. This cistern is 363 feet long, and 182 broad; the roof, arches, and sides are all brick work covered with terrass, and not in the least impaired by time. The roof is supported by three hundred and thirty-six marble pillars, of about forty and three quarter feet high, with spaces of intercolumniation of twelve feet. They stand lengthwise in twelve ranges, and twenty-eight in the breadth. Their capitals are partly finished after the Corinthian model — part of them are not finished. " There are abundance of wells falling into the cistern. When it was filling in the winter time, I have seen a large stream of water falling from a great pipe with a mighty noise, till the pillars have been covered with water up to the middle of the capitals." Dr. Walsh, whose travels in Turkey are so late as 183-, visited this subterranean reservoir, and confirms the account of Gyllius. Modern Rome is almost as bountifully supplied with water as the ancient city, not- withstanding the destruction or decay of the old aqueducts. But the Romans of this day are but a handful — perhaps 150,000 — to the populousness of the elder time; and this comparatively small number possess, without enjoying as they might, the advan- tage of overflowing fountains. The anarchy of the middle ages, as has been already stated, led to the destruction, among other works of art, of the aqueducts, and the Romans were again reduced to wells and springs, and the Tiber. A precarious supply of purer element had been occasionally obtained by repairing an ancient conduit — but neither the resources of the State, nor the skill of individuals, were equal to the undertaking of a permanent reparation. It was not until the pontificate of Nicolas V., that a restoration of an ancient aqueduct was attempted ; the Aqua Appia was then