WATER. 



to tte (Kaft, becaufe the curves of the feveral channels will 

 be at right angles to this vertical line, in the points where 

 the line interfefts the curves ; and this is true in whatever 

 pofition the wheel may be. Thus the aftion of the weight 

 continuing always beneath the extremity of the horizontal 

 radius of the axle, will oppofe the fame refiftance, as though 

 it afted upon the invariable arm of a lever, in the manner 

 of a bucket of water, which is drawn up out of a well by a 

 rope, winding on a roller, and the power required to raife 

 the weight will be always the fame. 



If the radius of the wheel, of which thefe hollow canals 

 ferve as bent fpokes, be equal to the height through which 

 the water is to be raifed, and confequently equal to the 

 circumference of the axle, or (haft, the power will be to 

 the load of water reciprocally as the radius of a circle to 

 its circumference, or direftly as i to 6^ nearly. M. de la 

 Faye recommended the machine to be compofed of four of 

 thefe canals, but it has often been conftrufted with eight. 

 The wheel is turned by the impulfion of the ftream upon 

 float-boards fixed on the circumference of the wheel, and 

 the orifices of the curvilineal canals dip one after another 

 into the water which runs into them ; and as the wheel 

 revolves, the fluid rifes in the canals, until it is as high as 

 the centre : it then runs out in a ftream from the holes in 

 the axis, and is received into the trough fixed beneath the 

 axis ; from thence it may be conveyed by pipes or troughs 

 to the required fituation. 



By this conftrviftion, the weight to be raifed offers always 

 the {^ame refiftance, and that is the leaft poifiblc, while the 

 power is applied in the moft advantageous manner which 

 the circumftances will admit of. Thefe conditions being 

 both fulfilled at the fame time, furnifti the moft defirable 

 perfeftion in a machine. This machine raifes the water by 

 the Ihorteft way, namely, the perpendicular or vertical line, 

 and in this refpeft is preferable to Archimedes's fcrew, 

 where the water is carried up a crooked and inchned path ; 

 and befides this each curved channel in this wheel empties all 

 the water it receives in every revolution, while the fcrew of 

 Archimedes delivers only a fmall portion of the fluid with 

 which it is charged, being often loaded with twenty times as 

 much water as is difcharged at one rotation, and thus re- 

 quiring an increafe of labour when a large quantity is in- 

 tended to be raifed by it. The horn-wheel would be one 

 of the moft perfeA machines for raifing water, were not its 

 powers confined to fuch altitudes as the femi-diameter of 

 the wheel. 



The Jlajh, or fen-miheel, comes next to be defcribed. — 

 This is a vertical wheel, made exaftly like thofe water- 

 wheels for turning mills which are called breaft-wheels, and 

 in the fame manner the wheel is furrounded at the lower 

 quadrant by a curved fweep of mafonry or breaft, to which 

 the floats of the wheel are fitted with the greateft accuracy, 

 but do not abfolutely touch. This wheel, being turned 

 j-ound in a direftion contrary to that in which a water-wheel 

 turns, will carry water before its floats, and raife it up 

 againft the breaft until it runs over the fame. The opera- 

 tion is juft the reverfe of the water-wheel ; and the only 

 dilFerence in the conftrudtion of the two machines is, that 

 the flafli-wheel requires no fliuttle to be placed at the top 

 of the breaft, becaufe the water muft be aUowed to run 

 freely away from the top of the breaft ; but the water- 

 wheel requires a ftiuttle or fluice to regulate the quantity of 

 xvater which ftiall flow to the wheel. 



It is by this kind of machine that the extenfive fens of 

 Holland are drained ; and in Lincoln and Cambridgefliire 

 they are ^Jfo ufed very extenfively. They are, in general, 

 7 



worked by the power of the wind, and are on a very large 

 fcale. ° 



Mr. Smeaton made a horfe-machine on this plan, which 

 raifed thirty-three hogflieads per minute, to the height of 

 four feet and a half, when it was worked by four horfes • 

 but a fluice was placed in the channel which admitted the 

 water to the wheel, fo as to fupply the water in a greater 

 or leffer quantity ; and by this means, the fame machme 

 could be adapted to the power of three or two horfes. 

 The crown or top of the breaft, over which the water 

 was delivered, was not elevated to the full height to which 

 the water was to be raifed, but it was laid twelve inches 

 beneath the furface, and the body of water which the wheel 

 raifed up was fufBcient to drive this depth of water before 

 it ; but to prevent the return of the water when the mill 

 ceafed working, two pointed doors were placed in the 

 channel leading from the wheel, like the gates of a canal- 

 lock : thefe doors opened freely, to let the water pafs, but 

 would (hut and flop the water from returning. The pro- 

 portions of this machine were as follows : 



Diameter of the track in which the 1 , ^ „ . , 

 horfes walked - - .| 26 feet 8 inches. 



Great cog-wheel fixed on the per-"^ 72 teeth 9 feet dia- 

 pendicular axis - - - j meter. 



Trundle worked by the wheel - 35 teeth 4^ feet djam. 



Diameter of the water-wheel on the 7 r 

 fame axis as the trundle - J ' + 



Breadth of the wheel ... 2 feet 2 inches. 



Number of its floats - . - 42 



The floats did not point to the centre of the wheel, but 

 formed tangents to a radius, equal to about half the radius 

 of the wheel. The floats of the wheel were very exaftly 

 fitted to the channel or pit in which it worked, fo as not 

 to touch. 



The hucket-nvheel is a very ancient method of raifing 

 water ; but it cannot hft water to a greater height than its 

 own diameter. The laft machine was tlie reverfe of the breaft 

 water-wheel, and the prefent is the reverfe of the over-fhot 

 water-wheel, for the circumference of the wheel is furround- 

 ed by buckets, which dip in the water beneath the wheel, 

 and take up water, which they difcharge at the top of the 

 wheel into an elevated trough or refervoir. The wheel is 

 mounted upon an horizontal axis, and turns upon pivots ; it 

 is put in motion by the force of a current of water ftriking 

 the float-boards fixed on the circumference of the wheel ; 

 or if there is no current in the water, it may be moved by 

 making the wheel hollow within for a man to walk in it, as 

 is common in fome kinds of cranes, or the wheel may be 

 turned by horfes. The rim, or circumference of the wheel, 

 is made hollow, and is divided into feveral compartments, to 

 form a number of boxes or buckets ; each bucket has an 

 opening into it at that end which will be the moft advanced 

 when the wheel turns ; and from this opening, a fpout or 

 trough projefts in a direAion parallel to the axis of the 

 wheel. When the wheel revolves, the buckets dip into the 

 ftream, and become filled with water ; but as the mouths 

 or fpouts are at the upper end when the buckets rife out of 

 the water, they cannot efcape, and each bucket carries up 

 its charge of water to the top of the wheel ; but the buckets 

 will have then become inverted, and the fpouts or openings 

 being at the lovveft part, that they difcharge the water 

 fiJeways through the fpouts into a trough properly placed 

 to receive it, and then the buckets defcend empty till they 

 dip into the Itream and are refilled. The objeAion to this 

 machine is, that the buckets b*gin to pour out the water 



fopie 



