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A supply of pure and wholesome water is an object so essential to the health and prosperity of a city, that it should form one of the leading features of the public improvements which characterize its growth. The advantages arising from it are so numerous, and the comforts so great, that every effort should be made to accomplish it.

The means which have been resorted to for such purposes in almost every city of importance in the Old World, are examples for us of the New, and should induce us early to avail ourselves of that important element of health. We contemplate with mingled emotions of wonder and admiration, those works of art which were achieved by ancient Rome in her palmy days of wealth and power, and among them we find that her Aqueducts hold a prominent place.

Among the ruins of cities whose history is shrouded in mystery on this continent, we find provisions for bringing water from distant sources. In the wilds of Central America, the persevering traveller finds ruined cities buried in the depths of the forest, where nature is at work covering and concealing them: among those ruins he tells us of the Aqueduct. We find them also among the ruins of cities along the western coast of South America. With such examples before us, we may consider that by the construction of the Croton Aqueduct for supplying the City of New-York with water has been secured an important measure for the promotion of its growth.

Many cities of the United States have directed their attention to this object, and some have been fortunate in finding a supply of water near at hand, but others will look towards distant sources for a supply, and will, ere long, resort to the construction of Aqueducts.

In the history of cities built in remote periods of antiquity, we find mention made of plans for supplying water, and among remains of those cities which are found at this day, are traces of Aqueducts. We have accounts of Aqueducts constructed under the reign of Solomon, and the remains of them still existing in Palestine, give evidence of an extensive acquaintance with the principles of hydraulics among the Hebrew architects. The Pools of Solomon, which are mentioned by travellers who combine in their researches a regard for the arts as well as the religion of Judea, are connected with a scheme for supplying Jerusalem with water.

The vast expense incurred in the construction of Aqueducts by the Ancient Romans, as well in Italy as in other countries of Europe, proves the value that was attached by that people to a plentiful supply of pure water, and the details of the plan of construction of the different works, evince an acquaintance with the principles of hydraulics which, at this day, is not generally accorded to them. That they understood the principle that water seeks the level of its source after encountering depressions in its conduit, is sufficiently proved by instances, in works constructed by them, where the inverted syphon of pipes was used in crossing valleys. That this plan was not generally adopted by them in cases where great expense has been incurred to maintain the uniform declivity of the conduit over valleys, may be accounted for perhaps by the want of proper material for the construction of pipes. In cases where this plan has been adopted leaden pipes were used, and since it is only within the last century that iron pipes have been invented, we may reasonably conclude that considerations of such a nature would have induced them to adopt the more expensive plan of maintaining the general inclination of the conduit by vast structures of masonry.

By substituting inverted syphons instead of maintaining a uniform declivity in the conduit, would not give the requisite discharge of water at the elevation of the terminus of the Aqueduct, and perhaps they preferred, rather than diminish this elevation of the supply of water, to incur the expense of high structures across valleys. The Roman Emperors, with all their power and the wealth which was at their command, knew how to perpetuate the glory of their reign by the erection of Temples, Palaces and other public buildings, and what is more natural than to suppose that in the construction of these Aqueducts, which were considered so essential to the public welfare, they should encourage works of such architectural magnificence? Whatever the reasons might have been for maintaining the elevation of their Aqueducts over valleys by such expensive structures, we have no right to charge them with the want of that knowledge which the plan of some of their Aqueducts clearly proves them to have possessed.

Trusting that it will be interesting to the reader, I shall present an account of some of the principal Aqueducts built by the Ancient Romans,—some of the modern Aqueducts of Italy and France; also of Aqueducts in other parts of the world. This account might be enlarged, to embrace a description of more of the modern Aqueducts of Europe; but sufficient will be presented, it is thought, to interest without detaining the reader too long in arriving at the principal object of this work,—a description of the Croton Aqueduct.

A view is given of the Aqueduct of Spoleto, in Italy. The bridge supporting this Aqueduct is remarkable for the slender form of the piers and their great height; being only ten and a half feet thick and two hundred and fifty feet high to the base of the arches. This Aqueduct was built by the Goths, a people who gave a model for Church Architecture which is much admired at the present day. It is said that they borrowed the idea of the form of their arch from the opening beneath an arbor of trees.

The plan of the bridge for the Croton Aqueduct at Harlem River has been criticised on account of the small thickness of the piers as compared with their height, and because they were not made piers of equilibrium; that is to say, having their bases broader, so as to include the line of thrust of the arches, so that if a portion of the bridge were removed, the remainder of the arches and piers would maintain their position. By the present plan the permanency of any one individual arch may be considered to depend upon that of the whole structure.1

The Aqueduct of Spoleto, has been standing about eleven hundred years and is still in a perfect state of preservation.

With proper care in preparing the foundations of the bridge at Harlem River, there is no good reason to fear that it will be less durable than that of Spoleto.