Let us assume that the ice field even up till then was hummocked from the beginning until N 

 points and, later to M points. From formula (6) we can write 



L 



(7) 



In = 



therefore 



Im = 



I 



M '■ 



1 + o.6yv ' 



L 



I +0.6M' 



I + 0.6Af 



h 



1 + 0.6M 



Table 84 is calculated by me according to formula (7), from which it follows that, for 

 example, if the field was ice hummocked up to 3 points, that is # = 3, and later it appears hum- 

 mocked to 5 points, that is, # = 5, then 



Im = 0.70 In. 



In other words, in the area of the field which is hummocked from 3 to 5 points, with the 

 values received by us, contracts to 30 per cent. 



TABLE 84. THE DECREASE IN THE AREA OF ICE WITH HUMMOCKING (IN PER 

 CENT OF THE INITIAL AREA) 



but 



We can derive the formula in some form from the same figure 103. As before, let 



where if max " ^^^ average thickness of the ice hummocked part of the ice field, in which the field 

 is not hummocked by the wind of a given force. 



287 



