This ingenious and useful contrivance was executed in 1810 but one main being found insufficient for the demand on the works, in 1818, another of 28 inches diameter, arid subsequently a third of 36 inches, was laid across the river. The two last conveyed filtered watered only."t

There are six engines at Dalmarnock, which propel the water across the Clyde, which is there about 100 yards broad, into the reservoirs in the city of Glasgow, to a height of 157 feet above the level of the river. The houses are generally very high,

* Hydraulia, p. 149. t An early instance of this mode of transmitting water across a navigable river is recorded by M. Gautier, a French engineer, in a work published in 1778, upon the construction of roads.

M. Gautier had been employed to devise means of supplying the harbor of Rochefort with good water. He discovered a copious source on the side of the Charente, opposite to that on which the town stands. He proposed

accordingly, to bring it across by iron pipes laid on the bottom of the river, protected by wooden frames against the risk of accident from the anchors of vessels. The project was rejected as impracticable or inexpedient. " Some " years after," says M. Gautier, when I had charge of the roads on the Rhone, and other works in Languedoc, while at Aries, I heard that a vessel had cast anchor in the Rhone, opposite the city, but when the commander wanted to sail again, he could not raise his anchor. This circumstance attracted much attention and ;