CLIMATIC INFLUENCES OF BODIES OF WATER 14? 



much heat to produce a given temperature in the same weight 

 of water. There are so many kinds of soil that if we were 

 to use soil instead of iron for this experiment, the results 

 would vary widely. 



162. Cooling of land and water. The land cools more rap- 

 idly than the water. As it is necessary to put more heat into 

 water than into land in order to raise its temperature a given 

 amount, so the water gives off this larger amount of heat 

 when it cools. Furthermore, as water cools it gives off its 

 heat slowly, and since much of the heat is in the deeper 



FIG. 76. Cities with different locations in the same latitude 



parts of the water, it is not readily given off. We may there- 

 fore expect that any body of water will be cooler in summer 

 than the neighboring land, at least during the daytime and 

 while the sun is shining, and that breezes from water to land 

 will be common. During the winter the water may remain 

 much warmer than the land. 



163. Extent of influence of water. Although the lake breezes 

 are local, the temperature effect of the lakes is carried much 

 farther inland. We need to study again the table of mean 

 monthly temperatures in order to see what this effect is. 

 Since the three points Grand Haven, Mich., Milwaukee, Wis., 

 and Madison, Wis. (fig. 76) are in the same latitude and 

 so located that one is close to the east shore of the lake, one 

 near the west shore, and one remote from the lake, we shall 

 have proper points for comparison. 



