CLIMATIC INFLUENCES OF BODIES OF WATER 149 



on the west, and less severe on either shore than at places 

 far distant from the lake but in the same latitude. 



164. Causes of difference between east and west shores. It 

 will be recalled that in connection with the study of the 

 wind movements of the earth we found that the United 

 States is in a belt of prevailing westerly winds. We have 



2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 



\ 



\ 



GRAND 

 HAVKN 



/\ 



ST.LOUIS 

 MAD SON 



V 



FIG. 77. Temperatures during a cold wave 



The diagram represents the variation in temperatures between three cities on the 



dates January 2 to January 15, 1913. Grand Haven is in the latitude of Madison, 



but its temperature is like that of St. Louis 



winds from all points of the compass, but our winds much 

 more frequently blow from a point west of a north-and- 

 south line than from a point east and west of such a line. 

 They are usually southwest, west, or northwest. It follows 

 from this that on most days of the year the air over the 

 country from the east of the lake has come across the lake. 

 On the west side the influence of the lake is very slight 

 excepting on a few days when the wind is from an easterly 



