VOL. LI.J PHILOSOPHICAL TRANSACTIONS. 3Sg 



and falls. — HI is a rod by which the sluice is drawn, and stopped at any height 

 required, by means of k a pin or peg, which fits several holes, placed in the 

 manner of a diagonal scale, on the face of the rod hi. — gl is the upper part of 

 the rod of the pump, for drawing the water out of the lower cistern, in order to 

 raise and keep up its surface at its desired height, in the head de ; to supply the 

 water expended by the aperture of the sluice. — mm is the arch and handle for 

 working the pump, which is limited in its stroke by n, a piece for stopping the 

 handle from raising the piston too high ; that also being prevented from going 

 too low, by meeting the bottom of the barrel. — o is the cylinder, on which a 

 cord winds, and which being conducted over the pulley p and a, raises r, the 

 scale into which the weights are put, for trying the power of the water. — sx the 

 two standards, which support the wheel, are made to slide up and down, to ad- 

 just the wheel as near as possible to the floor of the conduit. — w the beam 

 which supports the scale and pulleys ; this is represented as but little higher than 

 the machine, for the sake of bringing the figure into a moderate compass, but in 

 reality is placed 15 or l6 feet higher than the wheel. 



Plate 13, fig. 10, is a section of the same machine, where the same parts are 

 marked with the same letters as in fig. Q. Besides which, xx is the pump barrel 

 being 5 inches diameter, and 1 1 inches long. — y is the piston ; and z the fixed 

 valve. Gv is a cylinder of wood, fixed on the pump-rod, and reaches above the 

 surface of the water; this piece of wood being of such a thickness, that its 

 section is half the area of that of the pump-barrel, and will cause the surface of 

 water to rise in the head, as much while the piston is descending, as while it is 

 rising : and will thereby keep the gauge-red fg more equally to its height, 

 aa shows one of the two wires which serve as directors to the float, that the 

 gauge rod fg may be kept perpendicular ; for the same purpose also serves w, a 

 piece of wood with a hole to receive the gauge-rod, and keep it upright ; b is the 

 aperture of the sluice ; cc a kant-board, for throwing the water more directly 

 down the opening cd, into the lower cistern : and ce is a sloping board, for 

 bringing back the water that is thrown up by the floats of the wheel. 



Fig. 1 1 . represents one end of the main axis, with a section of the moveable 

 cylinder, marked o in the preceding figures — abcd is the end of the axis ; of 

 which the parts b and d are covered with ferrules or hoops of brass, e is a cy- 

 linder of metal ; the part marked p being the pivot or gudgeon, cc is the sec- 

 tion of a hollow cylinder of wood, the diameter of the interior part being 

 somewhat larger than the cylindrical ferrule b. aa is the section of a ferrule of 

 brass, driven into the end of the hollow cylinder, and which is adjusted to that 

 marked b, so as to slide freely on it, but with as little shake as possible, bb, 

 dd, gg, represent the section of a brass ferrule, plate, and socket, fixed on the 

 other end of the hollow cylinder ; the socket dd being adjusted to slide freely on 



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