HYDROSTATICS. 95 



Power of Water. 



If 100 gallons per minute be equal to a certain 

 power with one foot of fall, one gallon per minute 

 will perform the same work with 100 feet of fall. 



Balance in Hydrostics. 



If you poise in a balance a pitcher full of water, by 

 loading the opposite scale, and then hold in the 

 pitcher a block of wood, or any substance nearly the 

 size of the pitcher, but so that it shall not touch its 

 sides or bottom, although nearly the whole of the 

 water will have to run over the sides, and only a 

 spoonful may remain, yet the scales will continue 

 balanced ; and all this without regard to the weight 

 of the body you plunge into the water, taking, care to 

 hold it entirely clear of the pitcher so that it touch 

 it no where, for the effect will be the same if what 

 you plunge in be scooped hollow and made water 

 tight. A bladder blown up tied fast and held down 

 in the water, so as to leave only a spoonful of water 

 surrounding it, will keep the scales balanced just as 

 well as a block of lead of the same size. 



Weight of Water. 



A gallon ought to contain ten pounds of pure 

 water ; a pint twenty ounces or 34 '5 6 cubic inches. 



Capillary Attraction. 



If one end of a skein of thread be put into a vessel 

 of water, while the other hangs over the side, it will 

 very soon become a conductor of the liquid, which 

 will filter and run off until the vessel is nearly empty. 



Sea Water. 



The specific gravity of salt water is 1*026 or 1'028. 

 It freezes about 28*5, and does not appear materi- 



