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SPECIFIC GRAVITY. 



244. To Find the Specific Gravity of Solids, 



The most common method of finding the specific grav- 

 ity of a solid heavier than water, is to find the weight of 

 the body in the air (=: W), then suspend the body by a 

 light thread and find its weight in water ( W), and 

 divide the weight of the body in air by the weight of the 

 same bulk of water ( 238, Archimedes' Principle). 



W 

 Sp .Gr.= w -_ rw ,. 



(a.) The method is illustrated by the following example : 

 Weight of substance in air = 58| oz. 

 Weight of substance in water = 51 oz. 

 Weight of equal bulk of water = 7 oz. 

 Specific gravity = 58| oz. -5- 7J oz. = 7.8, Ans. 



245. To Find the Specific Gravity of Solids 

 Lighter than Water. If the given body be lighter 

 than water, fasten to it some body heavy enough to sink 



