TUEBINE WATER-WHEELS. 225 



below, where the blades are curved backwards, to receive 

 all the force of the escaping water. Fig. 254 is a view of 

 this wheel, showing the admission gates, and the wheel at 

 the top, for opening and shutting the gates at one movement. 



Tlie Reynolds wheel is placed under water, outside the 

 flume, and the current admitted at the side, as ah-eady 

 stated. The Van de Water wheel is placed within, and 

 on the bottom of the flume, in the floor of which a circu- 

 lar hole is cut, through which the water escapes. Both 

 are excellent wheels, and are among those most exten- 

 sively manufactured in tlie country the former by George 

 Tallcot, of New York, and the latter by the investor, H. 

 Van de Water, of Attica, N. Y. 



Turbine wheels, of the best construction, do not lose 

 more than one-seventh or one-eighth of the whole descend- 

 ing force of the water. Hence, the power of any stream 

 may be determined beforehand with much accuracy, if 

 the descent or head and the number of cubic feet of wa- 

 ter per minute are known. It has been already shown in 

 this work, that a single horse-power is equal to lifting 

 33,000 lbs. one foot, per minute. This is equivalent to 

 raising 530' cubic feet of water to the same height, or 53 

 cubic feet, ten feet high. A stream, then, which falls 10 

 feet, and discharges 53 cubic feet in a minute, or nearly 1 

 per second, has an inherent force of one horse-power. 

 Add one-seventh, making it about 60 cubic feet, and we 

 have the size of a stream for one horse-power, at ten feet 

 fall. Twenty feet descent would double the power, forty, 

 quadruple it, and so on ; and a similar increase result 

 from employing a larger stream. As examples, a small 

 wheel, seven or eight inches in diameter, will be sufficient 

 for such a purpose. One of this size, with 20 feet head, 

 and discharging 70 or 80 cubic feet of water per minute, 

 will possess about three horse-power ; and with forty feet 

 head, requiring over 100 cubic feet per minute, it will 

 have a power of eight or nine horses. 

 10" 



