80 



EXAMPLES. 



(2) To determine the specific gravity of a, solid. 



Let w be the weight which must be placed in the dish A, 

 to sink the stem to the point B in a liquid whose specific 

 gravity is s. 



Put the solid in the dish A, and let w' be the weight 

 which must be added to the solid to sink the stem to the 

 point B in the same liquid. 



. Then put the solid in the lower dish D, and let w" be the 

 weight required in the upper dish A to sink the stem to the 

 point B in the same liquid. 



Hence, the weight of the solid = w w', and its weight 

 in the liquid = w w". 



Therefore the weight lost, which is the weight of the 

 liquid displaced by the solid = w" w'. Hence, denoting 

 by 8 the specific gravity of the solid, we have 



8 



w w 



(3) 



If the liquid is the standard, s = 1, and (3) becomes 

 _ w w' 



- ^^TW" 



which is the specific gravity required. 



EXAMPLES. 



1. If an iceberg whose density is 0.918 float in a liquid 

 whose density is 1.028, what is the ratio of the part sub- 

 merged to that which is above water ? Ans. 8.3 : 1. 



2. How much of its weight will 112 Ibs. of iron lose, if 

 immersed in water, the density of iron being 7.25 times 

 that of water ? Ans. 15.448 Ibs. 



3. If 20 Ibs. of cork be immersed in water, with what 

 force will it rise towards the surface, its density being 0.24 

 times that of water ? Ans. 63 Ibs, 



