5. If the 7 axis is oriented along the principle direction of the ice exchange of the sea with 

 an adjacent part of the Arctic Basin, the projection of the velocity of the drift on the Y axis (V ^ 

 characterizes the velocity of the transport of ice beyond the bounds of the sea or the transport of 

 ice from without. The projection also of velocity of drift on the X axis ( ¥j.) characterizes only 

 the hummocking within the bounds of the sea, thereby not changing the total quantity of ice in the 

 sea. The changes in the quantity can be stipulated at the same time only by the accelerated 

 accretion of young ice in the areas of clear water which are cleared off during the drift. 



6. During the orientation of the projection of the velocity of the drift on the Y axis, the 

 transport out of ice which is linked with the freezing of areas of clear water proceeds to the side 

 of the Arctic Basin. In addition to this, no hummocks occur. In the case of the orientation of the 

 projection of the drift on the 7 axis, the location which is linked with the hummocking within the 

 bounds of the sea, has the entrance of the ice into the sea laterally from the Arctic Basin, which 

 is in contrast to the transporting out of ice. At the same time, three areas of water are not 

 formed . 



As a result of the appropriate calculation, Somov arrived at the following formula: 



Hn = //._, + A//„ +^ Aft ± ^{Hn-i -FAH) + ^ A/z„, W 



where H = the average thickness of the ice in the sea at a given moment, 



n 



^n-1 ^ '■h® average thickness of the ice in the sea at a preceeding moment, 



A ff„ = the increase in the average thickness of the ice in the sea for an examined space of 

 time. 



Ah = the thickness of the ice which had been formed in clear water for an examined period 

 n 



of time, 



W , = the transference of ice along the X axis for an examined period of time, 



XTl Lr 



Wyj^-j. = the transference of ice along the 7 axis for an examined period of time, 



a = the length of the sea (along 7 axis), 



b = the width of the sea (along X axis). 



The fourth component in the first part of the equation has a minus sign in the orientation of 

 Wy to the side of the Arctic Basin and the plus sign in the orientation of its side in the sea. The 

 last member of the right side enters only with the plus sign and only then when the preceding mem- 

 ber has a minus sign. The last three members 



^ Aft„ ± ^ {Hn-^ + AHJ + 'g^ AA„ 



for brevity are defined by means of A and are reckoned by the general correction for the average 

 thickness of the ice in the sea due to the drift. 



Thus formula (2) is derived: 



//n =//„_! +A/i„± A. (2) 



290 



