WATER. 



fpouts of wood attached to the two rims of the wheel, and 

 having an inclination of about twenty-five degrees to the 

 horizon, or to the axis of the wheel. The tubes are clofcd 

 at their outer extremities, which are fixed to the larger rim, 

 and open at the oppolite end. By this pofition the tubes^ 

 which in the motion of the wheel dip into the ftream, have 

 their mouths or open ends uppermoll, and fill with water. 

 As tliat fegment of the wheel rifes upwards, the mouths of 

 the tubes attached to it will alter their relative inclination, 

 but not fo much as to let their contents flow out until fuch 

 fegment of the wheel arrives at the top. The mouths of 

 thefe tubes are then relatively deprcfled, and they pour the 

 water into a wide trough placed on pivots, from whence it 

 is conveyed, as may be wanted, among the plantations of 

 canes. 



The only materials employed in the conftruftion of this 

 water-wheel, except the nave or axis, and the pofts on 

 which it refts, are afforded by the bamboo. The rims, the 

 fpokes, the ladle-boards or floats, and the tubes or fpouts, 

 or even the cords, are made of entire lengths, or fingle 

 joints, or large pieces, or thin flices, of the bamboo. Nei- 

 ther nails, nor pins, nor fcrews, nor any kind of metal, 

 enter into its conft:ru£lion : the parts are bound together 

 firmly by cordage of flit bamboo. Thus, at a very trifling 

 expence, is conftrufted a machine, which, without labour 

 or attendance, will furmfli, from a confiderable depth, a 

 refervoir with a conftant fupply of water, adequate to every 

 agricultural purpofe. 



Thefe wheels are from twenty to forty feet in diameter, 

 according to the height of the bank, and confequent eleva- 

 tion to which the water is to be raifed. A wheel of thirty 

 feet is capable of fuftaining with eafe twenty tubes or 

 fpouts, of the length of four feet, and diameter of two 

 inches in the clear. The contents of fuch a tube would be 

 equal to fix-tenths of a gallon, and the twenty tubes wo\ild 

 hold twelve gallons. A ftream of a moderate velocity 

 would be fufficient to turn the wheel at the rate of four re- 

 volutions in one minute, by which would be lifted forty- 

 eight gallons of water in that fhort period ; or in one hour, 

 two thoufand eight hundred and eighty gallons ; and fixty- 

 nine thoufand one hundred and twenty gallons, or upwards 

 of three hundred tons in a day. This wheel is thought by 

 fir George to exceed, in moil refpefks, any machine yet in 

 ufe for fimilar purpofes. The Perfian wheel, with loofe 

 buckets fufpended to the edge of the rim or fellies of the 

 wheel, fo common in the fouth of France, and in the Tyrol, 

 approaches neareft to the Chinefe wheel, but is vallly more 

 expenfive, and lefs fimple in its conftruftion, as well as lefs 

 ingenious in the contrivance. In the Tyrol there are alfo 

 bucket-wheels for lifting water in a circumference of wood, 

 hollowed into fcoops ; but they are much inferior either to 

 the Perfian or Chinefe wheel. 



Chain of Buckets. — This machine confifts of a number of 

 buckets attached to a chain or rope, the ends of which are 

 tniited together. The chain is conduced over a wheel, 

 which is turned by fome animal or mechanical power ; and 

 the chain hangs down from this wheel into the well from 

 which the water is to be drawn. The buckets at the lower 

 part of the chain become filled, and, by the motion of the 

 chain, the buckets attached to one part of the chain will 

 afcend full of water, whillt thofe on the oppofite fide are 

 defcending empty, with their mouths downwards. When 

 the full buckets of water turn over the upper wheel, they 

 difcharge their contents into a trough fixed near the wheel. 

 The molt convenient way of difcharging the water is to 

 make the upper wheel hollow, with divifions in it like the 

 tympanum; and the buckets, when they turn over, will 



pour their contents into the hollow fegments of the wheel, 

 and it will run off" through a hollow in the axis made for 

 that purpofe. The advantage of the chain of buckets over 

 the wheel is, that the chain can be made to defcend in a well, 

 or fmall fpace, where the wheel could not ; alfo, that the 

 chain may be ufed for greater depths than would be prafti- 

 cable for a wheel. 



The SpamJIi notra is a chain of buckets or earthen jars. 

 Mr. Townfend informs us, in his journey through Spain, 

 that the noira confifts of an cndlefs band or girdle, pafQng 

 over a fprocket- wheel : the band is long enough to reach 

 eighteen inches or two feet below the furface of water in a 

 well. All round this band, at the dift;ance of about fifteen 

 inches, are fixed jars of earthen-ware, which, as the band 

 turns, take up water from the well, and pour it into a cif- 

 tern fitted to receive it. A little afs, going round in a 

 circular walk with eafe, turns a trundle, which gives motion 

 to a cog-wheel, fixed on the fame axis with the fprocket- 

 wheel, on which the band is hung, and with which it turns. 

 This machine produces a conftant and confiderable fupply 

 of water, at a fmall expence, and with very little friftion. 

 As the air would obftruft the entrance of water into thefe 

 earthen jars or bottles, each jar has a httle orifice in its bot- 

 tom, through which the air efcapes ; but then water runs 

 out alfo, and a certain quantity falls back into the well. 



It is true, as the jars rife in one ftraight line, the water 

 which runs out of the fuperior jar is caught by that which is 

 immediately below it, yet ftiU there is a lofs ; and, befides 

 this inconvenience, the whole quantity is raifed higher than 

 the upper refervoir, at leaft by the diameter of the fprocket- 

 wheel, becaufe it is only in their defcent that the jars are 

 emptied. 



The fcreiu of Archimedes is a machine on a principle very 

 clofely allied to the horn-wheel ; but the curved channels 

 are wrapped fpiralwife round an axis, which is placed on an 

 inchned pofition, with the lower end immerfed in the water 

 which is to be raifed, and the upper end placed over the 

 edge of the refervoir into which the water is to be dehvered. 

 When this cylinder is turned round, it will take water up 

 in its fpiral channel, and r.iife it gradually to the elevated 

 end, and difcharge it into the refervoir. (See Screw.) 

 Although this machine is fimple in its general manner of 

 operation, its theory is attended with fome difficulties. 



If we conceive that a flexible tube is rolled regularly 

 about a cylinder, from one end to another, this tube or 

 canal will form a fcrew or fpiral, of which we fuppofe the 

 intervals of the fpires or threads to be equal to one another. 

 Suppofe this cylinder placed with its axis In a vertical pofi- 

 tion, if we put in at the upper end of the fpiral tube a fmall 

 ball of heavy matter, which may move freely, it is certain 

 that it will follow all the turnings of the fcrew from the top 

 to the bottom of the cylinder, defcending always as it would 

 have done, had it fallen in a right line along the axis of the 

 cylinder ; only it will occupy more time in running through 

 the fpiral. 



If we luppofe the cylinder placed with its axis horizon- 

 tally, and we again put the ball into one opening of the 

 canal, it will defcend, following the direftion of the firft 

 demi-fpire, until it arrives at the loweft point in this portion 

 of the tube, and then it will flop : for the weight of the 

 ball has no other tendency than to make it defcend in the 

 demi-fpire. The oblique pofition of the tube, with refpeft 

 to the horizon, caufes the ball, in defcending, to advance 

 from that extremity of the cyhnder whence it commenced 

 Its motion to the other extremity. When the ball is ar- 

 rived at the bottom of the firft demi-fpire, if we caufe the 

 cyhnder to turn on its axis, without changing the pofition 



of 



