ii is run v or engineeiung.

Book I.

546

nearly met, so that one man. with the two windlasses, raised or let down the wheel, as therewas occasion, the quantity of water within his power to raise being fifty tons, which wasmore than the weight of the water-wheel.

Fig. 538.

WATEU-WIIEfcl. AT I.ONDON URIL'OK WORK'

Near each end of the great axis of the water-wheel, a cog-wheel was fixed 8 feet indiameter, with forty-four cogs, working into a trundle of 4 feet 6 inches in diameter, andtwenty rounds, whose axis or spindle was of east-iron, 4 inches in diameter, lying in brasses,supported by strong timber framing at each end.

As the fulcrum of the levers was in the line of the axis of the trundle, in whatever situationthe water-wheel was raised or let down, the great cog-wheel was always equidistant fromthe trundle, and worked and geared with it.

A quadruple crank of cast-iron was attached to the end of the axis of the trundle, themetal being 6 inches square; each of the necks was distant 12 inches from the centre ofmotion ; the gudgeons of the cranks were sustained on brasses at each end, hv two head-stocks, fastened down by caps. One end of the axis was placed close to that of the axis ofthe trundle where it was 6 inches in diameter; at the other end was a slit: the crank ter-minated in the same manner, and an iron wedge was fixed one half into the slit at the endof the axis, and the other into that in the end of the crank, by which the axis turned thecrank about with it. To each of the four necks of the crank was united an iron spear orrod, jointed at the upper cud to its respective lever, and within 9 feet of the centre. Thelevers were 24 feet long, moving on centres in the middle of their length, and supported bythe frame; at each end of each lever a rod was jointed, which descended into the pump-barrel, the forcers being fastened to it. Each end of the four levers worked a quadrupleforcing-pump, which consisted of four cast-iron barrels or cylinders 4 feet 9 inches long, 7inches bore above, and 9 inches below, where the valves were placed ; the four barrels werefastened by screwed Handies over four holes in a hollow trunk of cast-iron, which had fourvalves in it; just over these holes, at the joining on of the bottom of the barrels, and at oneend of the hollow trunk, was a sucking pipe and grate touching the water, which suppliedall the four pumps alternately. To carry away the water which they forced out, there pro-ceeded from the lower part of each pump-barrel a neck, turning upwards archways, whoseupper part was cast with a flanch, to screw up to the under side of another square trunk,which received the necks of all the four barrels which necks had bores of 7 inches indiameter, and over the holes in the trunk communicating with them were placed four valvesat the jointings or Handles. The square forcing-trunk was cast with four bosses or pro-tuberances standing out against the valves to give room for their opening and shutting ;and on the upper side of the trunk were four holes, stopped with plugs, to take out whenthe valves required cleansing. One end of this trunk was stopped by a large plug, and tothe other the iron pipes were joined by Handles, through which the water was forced up 120feet, or to any height or place required. In addition to this four-barrelled pump, therewas a similar one at the opposite ends of the levers. At the other end of the water-wheel