312 AIR. 



Q. Why are there WAVES in the sea ? 



A. The wind (acting on the surface 

 of the sea) piles up ridges of water, 

 which leave behind an indentation : as 

 the water on all sides rushes to fill up 

 this indentation, the disturbance spreads 

 on all sides, and billow rolls after billow. 



Q. Why does WIND in England generally feel 

 COLD? 



A. Because a constantly changing 

 surface comes in contact with our body, 

 to draw off its heat. 



Q. Why is a ROOM (even without a fire) 

 generally WARMER than the OPEN AIR ? 



A. As the air in a room is not subject 

 to much change, it soon becomes of the 

 same temperature as our skin, and no 

 longer feels cold. 



Q. Why do we generally feel COLDER out-of- 

 doors ? 



A. Because the air (which surrounds 

 us) is always changing ; and as fast as 

 one portion of air has become warmer by 

 contact with our body, another colder 

 portion surrounds us to absorb more heat. 



Q. Why are HOT FOODS made COOL by 

 BLOWING them? 



