Cooper'' s Rotatioe Piston. 316 



No. 2, rotative engine with eight men, exerting an estima- 

 ted power of fifty pounds per man, threw from a hail inqh 

 pipe, one hundred and forty eight feet horizontal, and one 

 hundred and three feet in height. The atmosphere was 

 nearly calm and the thermometer at 63°. The two last men- 

 tioned iengines were made to discharge a laige quantity, with- 

 out particular reference to power. One constructed for 

 power alone, would probably much exceed either of the 

 above. 



The quantity of water discharged by a No. 1 1 engine is 

 live hundred and twenty five gallons for each hundred revo- 

 olutions. By a No 7, three hundred and four gallons, each 

 hundred revolutions. By a No 3, one hundred and twenty 

 eight gallons, each hundred revolutions. 



In the No. 1 1 engine, the revolving cylinder is thirteen 

 inches long, and eight inches in diameter, and the surface 

 acting upon the water is forty square inches. In No. 7, the 

 revolving cylinder is twelve inches long, six and a half inch- 

 es in diameter, and it has a surface of thirty square inches. 

 The No. 3 cylinders are nine inches long, five inches in di- 

 ameter, and eighteen square inches acting surface. 



The result of experiments upon it as a pump proved sat- 

 isfactorily, that the only deduction from the power apphed, 

 after the inertia of the water and pump had been once over- 

 come, was short of seven per cent, including friction. In the 

 old pumps ten per cent is lost in the reciprocating motion 

 alone, exclusive of friction. (Allen's Mechanics, p. 229.) 



When, upon examination of this pump, it is found that the 

 quantity of water raised is sufficient to fill the pipe through 

 which it is discharged to its full extent, and to keep it contin- 

 ually filled, and moving at almost any velocity of which ma- 

 chinery is capable ; it is difficult to imagine what more can 

 be effected by any machine, as nothing can give an increase 

 of quantity, where no room is left unoccupied. The only 

 chance for improvement then, is to so construct a pump as 

 to give as much in quantity and with less power, or in other 

 words, one which by the application of one hundred pounds 

 power, will raise more than ninety three pounds of water. 



The rotative piston is applicable to a variety of purposes, 

 in some of which, particularly steam, the experiments have 

 been very satisfactory. 



