USES OF WATER 



119 



The density of liquids may be found by a comparison 

 of the weights of equal volumes of water and the liquid 

 whose density is to be determined. Special bottles, com- 

 mercially called "Specific Gravity" bottles, are used for 



FIG. 106. Apparatus for Determining the Density of Insoluble Substances 

 Which are Lighter than Water. 



this purpose. After the bottle has been dried, weigh it 

 filled with the liquid whose density is undetermined. 

 The density of several liquids should be determined. 

 See table of densities on page 36. 



QUESTIONS 



1. Which is denser, cream or milk? 



2. Will gold float or sink in mercury? 



3. Why is it easier to swim in the water of the ocean than in 

 the water of Lake Erie? 



4. As a vessel passes from the river into the ocean, will its 

 water line rise or fall? 



