Preparations and Equipment. 67 



one tier. The keel consists of two heavy American 

 elm logs 14 inches square ; but, as has been mentioned, 

 so built in that only 3 inches protrude below the outer 

 planking. The sides of the hull are rounded downwards 

 to the keel, so that a transverse section at the midship 

 frame reminds one forcibly of half a cocoanut cut in 

 two. The higher the ship is lifted out of the water, 

 the heavier does she, of course, become, and the greater 

 her pressure on the ice, but for the above reason 

 the easier also does it become for the ice to lift. To 

 obviate much heeling, in case the hull should be lifted 

 very high, the bottom was made flat, and this proved 

 to be an excellent idea. I endeavoured to determine 

 experimentally the friction of ice against wood, and 

 taking into account the strength of the ship, and the 

 angle of her sides with the surface of the water, I 

 came to the conclusion that her strength must be many 

 times sufficient to withstand the pressure necessary to 

 lift her. This calculation was amply borne out by 

 experience. 



The principal dimensions of the ship were as 

 follows : Length of keel, 102 feet; length of water- 

 line, 113 feet; length from stem to stern on deck, 

 128 feet; extreme breadth, 36 feet; breadth of water- 

 line, exclusive of ice-skin, 34 feet; depth, 17 feet; 

 draught of water with light cargo, 12^ feet ; displacement 

 with light cargo, 530 tons ; with heavy cargo, the draught 

 is over 1 5 feet, and the displacement is 800 tons ; 



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