BAYS AND LIKES. 175 



in equalizing the differences of the temperature on 

 the land. In fact the farther we go towards the 

 interior of the country, the greater do we find the 

 fluctuations of the temperature of the air and of the 

 ground. 



The temperature of bays and of inland lakes, is, 

 on account of the neighbouring masses of surround- 

 ing land, subject to considerably greater oscillations 

 than is that of the ocean. Thus the mean summer 

 temperature of the Baltic is about 15° or 17°'5 C. 

 (59° or 63 0, 5 P.), and on some summer days it is 

 found to amount to 20° or 23° C. (68° or 73° F.), 

 while large tracts of tins sea are frozen in the 

 winter. 



In the following table are collected some in- 

 stances of the extreme temperatures which have 

 been observed in the air at the places whose names 

 are given : — 



