ARCTIC ICE SLEDGING 197 



over the frozen surface of the polar ocean — on the 

 upward journey for fear that they may prevent further 

 advance; on the return journey for fear they may cut 

 him off from the land and life, leaving him to wander 

 about and starve to death on the northern side. Their 

 occurrence or non-occurrence is a thing impossible to 

 prophesy or calculate. They open without warning 

 immediately ahead of the traveler, following no appar- 

 ent rule or law of action. They are the unknown 

 quantity of the polar equation. 



Sometimes these leads are mere cracks running 

 through old floes in nearly a straight line. Sometimes 

 they are zigzag lanes of water just wide enough to be 

 impossible to cross. Sometimes they are rivers of 

 open water from half a mile to two miles in width, 

 stretching east and west farther than the eye can see. 



There are various ways of crossing the leads. One 

 can go to the right or the left, with the idea of finding 

 some place where the opposite edges of the ice are near 

 enough together so that our long sledges can be bridged 

 across. Or, if there are indications that the lead is 

 closing, the traveler can wait until the ice comes quite 

 together. If it is very cold, one may wait until the 

 ice has formed thick enough to bear the loaded sledges 

 going at full speed. Or, one may search for a cake of 

 ice, or hack out a cake with pickaxes, which can be 

 used as a ferry-boat on which to transport the sledges 

 and teams across. 



But all these means go for naught when the "big 

 lead," which marks the edge of the continental shelf 

 where it dips down into the Arctic Ocean, is in one of 

 its tantrums, opening just wide enough to keep a 



