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THEORY AND PRACTICE OF ENGINEERING.

Book II.

MACHINE AT MAULY

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A

water-wheels, which first raised the water from the river to a cistern 150 feet high and 600feet distant, then worked the balance-beams of the pumps, which raised the water to asecond cistern, 175 feet above the first, and 19-14 feet from the river; from thence it waslifted by other pumps to a strong tower or reservoir, 502 feet above the river and 3684 fromit; whence the 'water was conveyed by an aqueduct to the great reservoirs which supply thegardens of Marly and Versailles.

Fig. 1871. is a longitudinalview or section of one of the 14wheels : on the bed of the river afloor was laid on piles filled in withmasonry, and 14 feet above thiswas the platform which sup-ported the pumps. To the axleof the great wheel a crank wasattached, which communicatedmotion to the balance-beam, andthis worked the piston rods of fourpumps on each side, which suckedand forced the water alternately.

To prevent the air from enteringthe pump-barrels, a fifth suction-pump raised water to a cisterna little above the four others.

Fig. 1872. shows how thesepumps at the first and secondcisterns were worked : a crankon the other end of the axle ofthe great water-wheel communi-cated motion to the two ironchains, and these, by means of twoother cranks, alternately workedthe two iron frames to whichthe piston rods of six pumpsw'ere attached. All these pumpsworked independently of eachother, and each reservoir had sixpumps for the purpose of supply-ing it when reparations were re-quired. The whole system maybe drawn up by the crab shownin the figure. The pulley in themiddle may be moved into anyposition along the head of theframe, by means of the winch atthe side.

Fig. 1874. is one of the eightsuction and forcing-pumps putin motion by the crank of thegreat water-wheel ; when thepiston ascended, the water fromthe river rose in the suction pipe,opened the first valve, filled thewhole of the horizontal pipe anda part of the barrel: when it de-scended, it forced the water inthe barrel, which by its pressuresclosed the first valve, opened thesecond, mounting in the branch;when the piston remounted, thesecond valve closed, and the firstreopened to admit more water;

B represents one of the suction-pumps, which supply the small cisterns to keep the eightpump-barrels from leakage.

Fig. 1873. is one of the pumps of the first and second cisterns : the barrels were carriedon iron bars, and the piston rod attached to an iron frame; at the upper part of this latterare shown two small rollers to facilitate the operation of drawing the whole up. The mannerof working is the same in this example as previously explained, when on the description of

Fig. 1873.

Fig.1874.

Fig. 1875.

:. 1870.