160 EFFECTS OF HEAT. 



Q. Why is LINEN DEIED sooner in the open 

 AIR, than in a confined room ? 



A. Because the particles of vapour 

 are more rapidly removed from the 

 surface of the linen by evaporation. 



Q. Why are WET SUMMERS generally SUC- 

 CEEDED by COLD WINTERS ? 



A. Because the great evaporation 

 (carried on through the wet summer) 

 reduces the temperature of the earth lower 

 than usual, and produces cold. 



Q. Why is ENGLAND WARMER than it used to 

 be, ivhen AGUES were so common ? 



A. Because it is better drained and 

 better cultivated. 



Q. Wliydoes DRAINING land promote WARMTH. ? 



A. Because it diminishes evaporation ; 

 in consequence of which less heat is 

 abstracted from the earth. 



Q. Why does CULTIVATION increase the 

 WARMTH of a country? 



A. 1st Because hedges and belts of 

 trees are multiplied; 



2ndly Because the land is better 

 drained ; 



3rdly Because the land is dug and 

 ploughed; and 



