Chap. XVII.

MACHINES FOU RAISING WATER.

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T* ; the lower part of the chain, from T 8 to T 3 , is crossed by small bars, which engage inthe rebates of the wheel Q, by which means this part of the chain is prevented fromtouching that which envelopes the circumference, and an equilibrium is produced between thechain and the rod SS, by the compensation of the arm of the levers produced by the spirals.On the wheel R is a cord, whose other end surroundsthe wheel V, 2 feet in diameter ; the axle of thiswheel is common to another W, 1 foot in diameter,on whose circumference is a cord passing over apulley, and suspending a weight in a box X at theextremity of the radius of the quarter circle Y, inwhose circumference are pulleys which receive thecord from the wheel W ; Z is a weight to counter-balance that of the chains, and preserve a perfectequilibrium. On the axle O is a cogged wheeldriving a fly to maintain uniformity of motion:at the extremity of the chain is a copper bucketF with a clasp valve in its bottom ; the rod Scarries the bucket A, which contains three timesas much as the preceding ; it has likewise a valve inits bottom, opening by means of a catch, whichmeets a pin in the cistern C ; the buckets havecopper rollers at their sides which work on theguides i,i; when the lesser bucket descends it meetsthe pin A. which by means of a lever opens a valvein the cistern B, allowing the water to flow intothe bucket A. "When the smaller bucket F is full,it runs over into the basin G, and thence throughB into the great bucket A, until this is suffi-ciently full; the lesser bucket begins to ascend, andceasing to rest on the pin the valve in B closes,and the water in the basin G, supplied from thesource, runs by a waste pipe into the bucket A,continuing to precipitate its descent. The greatwheel Q. which carries the lesser bucket, being6 feet in diameter, while P, which carries the greaterbucket, is only 2, and the fall being 10 feet, thewater will be raised 30; when the small bucketarrives at the floor L it is arrested by a catch f; atthe same time its valve is opened by a pivot at e,and discharges its contents into a trough or cisternof supply : at the same time the greater bucketmeeting a pivot in the cistern C, which opens itsvalve, discharges its water through the channelD, both being empty and the lesser the heaviest, itdescends and raises the greater, again to perform thesame manoeuvre. The circumferences P and Q areformed spirally, so that the weight of the chainsmay always be in equilibrio, but this is moreparticu arly effected by the quarter circle Y, and itsweight Z, which acts on the wheel Q, when theradius Y’ Z X is in an horizontal position, that is,when the chain T is unrolled ; for as this is effected,the lever Y X approaches a vertical position, andthe weight of the chain diminishing the actionof the weight X, diminishes also, until the weightZ ceases to act on the wheel R, which happens whenthe weight contained in X is at the bottom of itsbox ; thus the cord to which this weight is attachedis kept constantly stretched. When the lesser bucketbegins to descend, the movable weight in X remounts, before any motion is communicatedto the lever Y X; but as the chain T unrolls from the wheel Q. its weight increasing andthat of S diminishing by rolling on the wheel P, the lever Y X approaching a horizontalposition, the weight Z again acts on the wheel R, retarding its velocity and maintaining theproper equilibrium in order to prevent the bucket F descending too* fast. The fly-wheelprevents the machine from receiving any shock when the buckets are emptying themselves:this machine works very slowly, only raising the lesser bucket once in 5 minutes; it wasconstructed in Buckinghamshire , to supply the house and gardens of Sir John Chester,

Fig. 1888.