WATER 



87 



water is the moderation of both summer and 

 winter temperatures of the earth. It is not 

 easy to estimate the total magnitude of this 

 effect, but the manner in which it comes about 

 is well illustrated by the differences between 

 seaboard and inland climates or between the 

 climate of a large part of the United States, 

 which is a continental climate, and that of 

 Western Europe, which is essentially an in- 

 sular climate. In the most extreme form 

 such moderation of climate is to be observed 

 on the high seas and upon small islands. 

 There are found the smallest known differences 

 between the mean temperatures of different 

 months of the year and of different hours of 

 the day, and the least tendency to violent 

 changes of temperature. The calculation of 

 Zenker regarding normal temperatures may 



