USES OF WATER 161 



of any material, referred to water as a standard, is called its 

 specific gravity. The specific gravity of any material may 

 be obtained by finding the buoyant force which the water 

 exerts upon it, when it is entirely submerged. The total 

 weight of a body, divided by the loss of weight in water, gives 

 the specific gravity of the body. The specific gravity of a 

 liquid may be learned by dividing the loss of weight of a body 

 of known weight, when immersed in a given liquid, by the 

 loss of weight of the same body, when immersed in water. 



References : 



1. 1501:135-137. Drinking Water. 



2. 1503 : 19. Water in Living Things. 



3. 1601 : 155-156. Amount of Water Used by Crops. 



4. 1605 : 67. Importance of Water. 



5. 1710:61-64. Water. 



6. 1803 : 48-50. The Hydraulic Elevator and City Water 



Supply. 



7. 1803 : 51-52. The Principle of Archimedes. 



a. 1606 : 47-51. Why Moisture is Important. 



b. 1701 : 55. Uses of Water. 



c. 1704 : 21-23. Uses of Water. 



d. 1705:161-162. Water. 



e. 1706 : 31-38. Water in Nature. 



/. 1711 : 1-2. Water and its Occurrence. 



g. 1712 : 60-61. Uses of Water. 



Experiment 60. Specific Gravity Buoyancy. 



Apparatus : Platform balance on a stand, and set of weights, 

 battery jar, 6" X 8", pieces of iron, lead, glass, aluminum, and 

 blocks of wood. 



a. Weigh the piece of iron in air, and then weigh it while it 

 is entirely submerged in water. Subtract this last weight 

 from its weight in air. This is the loss of weight and is due 

 to the buoyant force of the water, and is equal to the weight 



