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 continual zone of open water or impracticable young ice in the center, as occurred on our upward journey of 1906 and the never-to-be-forgotten return journey of that expedition, when this lead nearly cut us off forever from life itself.
A lead might have opened right through our camp, or through one of the snow igloos, when we were sleeping on the surface of the polar sea.
Only--it didn't.
Should the ice open across the bed platform of an igloo, and precipitate its inhabitants into the icy water below, they would not readily drown, because of the buoyancy of the air inside their fur clothing.

A man dropping into the water in this way might be able to scramble onto the ice and save himself; but with the thermometer at 50 deg.

below zero it would not be a pleasant contingency.
This is the reason why I have never used a sleeping-bag when out on the polar ice.

I prefer to have my legs and arms free, and to be ready for any emergency at a moment's notice.

I never go to sleep when out on the sea ice without my mittens on, and if I pull my arms inside my sleeves I pull my mittens in too, so as to be ready for instant action.