Chap. 6.] Afine•speci.men of Hydraulic Machinery . 301
sent year (1840) to visit Fair Mount. Six breast wheels (15 feet long and16 feet in diameter) were in Operation ; each, by a crank on one end ofits axle, communicating motion to the piston rod of a single pump. a Thepumps are double acting, the same as figured and described at page 271.They are placed a little below the axles of the wheels and in nearly a ho-rizontal position. The cylinders are 16 inches diameter; and, that thewater may not be pinched in its passage into and escape from them, theinduction and eduction pipes are of the same bore; and all angles orabrupt changes in their direction and those of the mains are avoided. Thestroke of two or three of the pumps was four feet, and their wheels madefourteen revolutions per minute : the others had a stroke of five feet teninches, and the wheels performed eleven revolutions in a minute, conse-quently the Contents of the cylinders of the latter were emptied into thereservoirs twenty-two times in the same period, and those of the formertwenty-eight times. The cylinders are fed under a head of water fromthe forebays and they force it to an elevation of 96 feet, through a dis-tance of 290. An air chamber is adapted to each.
1t is impossible to examine these Works without paying homage to theScience and skill displayed in their design and execution; in these res-pects no hydraulic works in the Union can compete, nor do we believethey are excelled by any in the World. Not the smallest leak in any ofthe joints was discovered ; and, with the exception of the water rushingon the wheels, the whole Operation of forcing up daily millions of gallonsinto the reservoirs on the mount, and thus furnishing in abundance one ofthe first necessaries of life to an immense population—was performed withless noise than is ordinarily made in working a smith’s bellows ! Thepicturesque location, the neatness that reigns in the buildings, the walksaround the reservoirs and the grounds at large, with the beauty of the sur-rounding scenery, render the name of this place singularly appropriate.
Dr. T. P. Jones, the talented editor of the Journal of the Franklin In-stitute , promised his readers “ A history of the origin, progress and pre-sent state of the Water-works at Fair Mount,” some years ago, but whichhas not yet been published. His familiarity with the subject in general,and with those works in particular, would make the history highly inter-esting to the present generation, and a source of valuable Information tofuture ones. See Journal of the Franklin Institute , vol. iii, first series;which contains a plan and section of one of the wheels and one of thepumps.
a What a contrast with the old works at London bridge, where one wheel worked six-teen small pumps; the friction of the numerous pistons and the apparatus for movingthem consuming a great portion of the power employed.