226 MACHINERY IN CONNECTION WITH WATEE. 



The simple rule given in the second paragraph of the 

 present chapter, for determining the velocity of a current 

 of water spouting out under any given head, will enable 

 any one who understands arithmetic to calculate the 

 proper speed of a turbine wheel, which varies with the 

 head and the diameter of the wheel. It is found that the 

 buckets or blades should move with about two-thirds the ve- 

 locity of the current as it rushes from the flume ; hence, 

 as an example, under a head of 16 feet, which drives out 

 a stream about 22 feet per second, the exterior of the 

 turbine wheel should move about 14 or 15 feet per second. 

 If 1 fo#t in diameter, it should therefore revolve five 

 times per second ; or, if 2^ feet in diameter, only twice 

 per second. Other examples may be readily computed. 



There are occasional opportunities for employing water 

 power for driving farm machinery as thrashing ma- 

 chines, mills for grinding feed, corn shellers, wood saws, 

 straw cutters, etc., by bringing streams along hill-sides, 

 or over bluffs; in which cases, turbine wheels would be 

 cheaper than steam-engines, and require neither food nor 

 fuel. The water of small streams might be saved in dams 

 or ponds, giving a power of five or six horses for 

 one day in each week for grinding, thrashing, and other 

 purposes, 



THE WATER-EAM. 



One of the most ingenious and useful machines for ele- 

 vating water is the Water-ram. It might be employed 

 with great advantage on many farms, were its principle 

 and mode of action more generally understood. By means 

 of a small stream, with only a few feet fall, a current of 

 w^ater may be driven to an elevation of 50 feet or more 

 above, and conveyed on a higher level to pasture-fields 

 for irrigation, to cattle-yards for supplying drink to 

 domestic animals, or to the kitchens of dwellings for cu- 

 linary purposes. 



