294 EXAMPLES. 



The theory of turbines is too intricate a subject to be 

 considered in this treatise. For a general classification of 

 turbines, with descriptions, illustrations, and discussions of 

 these machines, as Avell as for a further development of 

 hydraulic machines in detail, the student is referred, among 

 other treatises, to the following : Fairbairn's Millwork and 

 Machinery, Colyer's Water-Pressure Machinery, Barrow's 

 Hydraulic Manual, Glynn's Power of Water, Prof. Uiiwin's 

 Hydraulics. 



EXAMPLES. 



1. In a hydrostatic bellows (Fig. 70), the tube A is \ of 

 an inch in diameter, and the area DE is a circle, the diam- 

 eter of which is a yard. Find the weight which can be 

 supported by a pressure of 1 Ib. on the water in A. 



Ans. 82,944 Ibs. 



2. Describe the siphon and its action. What would be 

 the effect of making a small aperture at the highest point 

 of a siphon ? 



3. A prismatic bell is lowered until the surface of the 

 water within is 66 feet below the outer surface; state 

 approximately how much the air is compressed. 



Ans. To % of its original volume. 



4. If a prismatic bell 10 feet high be sunk in sea water 

 until the water rises half way up the bell, find how far the 

 top of the bell must sink below the surface, the tempera- 

 ture remaining the same. 



Assume the water barometer 38 feet for sea water. 



Ans. 28 feet. 



5. In the position of the bell in Ex. 4, find how much 

 air must be forced into it in order to keep the water down 

 to a level of 2 feet from its bottom. 



Ans. 0.72 W, where W is the weight of the air in the 

 bell when at the surface, 



