120 EFFECTS OF HEAT. 



boil if immersed in a liquid which boils at a higher degree. 

 Thus a cup of ether can be made to boil in a saucepan of 

 water. A cup of water in a saucepan of brine or syrup. 

 But a cup oj water will not boil if immersed in ether; nor a 

 cup of syrup in water. 



Q. Why are CLOUDS HIGHER on a FINE DAY ? 



A. 1st Because the air (expanded 

 by heat) drives them higher up : and 



2ndly The clouds themselves are 

 lighter, and therefore more buoyant. 



Q. Why are the CLOUDS LIGHTEB on a FINE 

 DAT? 



A. Because their mists are either 

 absorbed by the dry air, or vapourized by 

 the hot sun. 



Q. Why is a CUP PUT topsy-turvy into a 

 FRUIT-PIE ? 



A. Its principal use is to hold the 

 crust up, and prevent it from sinking, when 

 the cooked fruit gives away under it. 



Q. Does not the cup PREVENT the FRUIT of 

 the pie from BOILING OVER ? 



A. No, by no means ; it would rather 

 tend to make it boil over, than otherwise. 



Q. WHY would the cup tend rather to MAKE 



the FRUIT BOIL OVER? 



A. As soon as the pie is put into the 



