WIND. 295 



Q. How can HILLS and MOUNTAINS ALTER 

 the course of the WIND ? 



A. Suppose a wind, blowing from the 

 north, comes to a mountain, as it cannot 

 pass through it, it must either rush back 

 again, or fly off at one side (as a marble 

 when it strikes against a wall). 



Q. Do MOUNTAINS affect the wind in any 

 OTHER way ? 



A. Yes ; many mountains are capped 

 with snow, and the warm air is condensed 

 as it comes in contact with them ; but as 

 soon as the temperature of the wind is 

 changed, its direction may be changed 

 also. 



Suppose A B C to be three columns of air. A, the 

 column of air which is cooling down ; B, the column to 

 which the sun is vertical; and C, the column which is 

 to be heated next In this case the cold air of A will 

 rush towards B C, because the air of B and C is hotter 

 than A. But suppose now C to be a snow-capped 

 mountain. As the hot air of B reaches C, it is chilled; 

 and (being now colder than the air behind) it rushes 

 back again towards A, instead of following the sun. 



Q. How can the OCEAN affect the direction of 

 the WIND ? 



A. When the ocean rolls beneath the 

 vertical sun, the water is not made so hot 

 as the land ; and (as another change of 



