356 ICE. 



Q. Why does the DEPTH of the water RETARD 



itS FREEZING? 



A. As the whole volume of water 

 must be reduced to 42 degrees before 

 the surface will freeze, the deeper the 

 water, the longer it will be before the 

 whole volume is thus reduced. 



Q. Wliy do SPRINGS at the bottom of a lake 



PREYENT itS FREEZING? 



A. Because they keep continually 

 sending forth fresh water, which prevents 

 the lake from being reduced to the neces- 

 sary degree of coldness. 



Q. Why is it COLDER in a THAW than in a 

 FROST? 



A. When frozen water is thawed, it 

 absorbs heat from the air and objects 

 around to melt its ice, in consequence 

 of which the cold is greatly increased. 



Q. Why is it WARMER in a FROST than in a 

 THAW ? 



A. When water freezes it gives out 

 its latent heat, in order that it may be 

 converted into solid ice; and as much 

 heat is liberated from the water into the 

 air, we feel warmer. 



