Cooper's Rotative Piston. 315 
No. 2, rotative engine with eight men, exerting an estinia- 
ted power of fifty pounds per man, threw from a half inch 
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 53°. The two last men- 
tioned engines were made to discharge a large 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, 11 engine is 
five hundred and twenty five gallons for each hundred revo- 
olutions. By a No 7, three hundred and four gallons, each 
hundred revolutions. a No 3, one hundred and twenty 
eight gallons, each hundred revolutions, 
In o. 11 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 rotative piston is applicable to a variety of purposes, 
in some of which, particularly steam, the experiments have 
been very satisfactory. 2 e * 
