THE YERMAK ICE BREAKER. " 459 



The distance that one can go through the ice will depend upon the 

 quantity- of fuel, and a.s liquid fuel i.s more efficient than coal, it should 

 be accepted for the polar ice breaker. That fuel is easily put into 

 an}' compartment of the ship, so that on entering the ice one can have 

 as much of that fuel as the ice belt and the shape of the vessel allows. 

 Liquid fuel has another advantage particularly applicable to ice break- 

 ing, where the speed of the engine is changed so often. With the 

 liquid fuel you stop burning instantaneously, while with the coal you 

 burn it unnecessaril}^ every time you unexpectedly reduce your full 

 speed to a dead slow. Li(|uid fuel is easily pumped from one part of 

 the ship to the other, and can be used for trimming and heeling 

 purposes. 



All these deductions are preliminary. 1 have to think over them, 

 and maybe more detailed study of the material we collected will force 

 me to make a slight modification of what I have stated in this paper. 

 But there will be no moditication in my idea that the exploration of 

 the Arctic and Antarctic ought to be done with the help of the polar 

 ice breakers. 



