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 Aque-

ducts 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.