Considerable discussion has taken place as to how the beaver sinks his wood—­for of course he must sink it, else it would freeze into the ice and be useless.  One theory is that the beavers suck the air from each stick.  Two witnesses declare to me they have seen them doing it; and in a natural history book of my childhood there is a picture of a beaver with the end of a three-foot stick in his mouth, sucking the air out.  Just as if the beavers didn’t know better, even if the absurd thing were possible!  The simplest way is to cut the wood early and leave it in the water a while, when it sinks of itself; for green birch and poplar are almost as heavy as water.  They soon get waterlogged and go to the bottom.  It is almost impossible for lumbermen to drive spool wood (birch) for this reason.  If the nights grow suddenly cold before the wood sinks, the beavers take it down to the bottom and press it slightly into the mud; or else they push sticks under those that float against the dam, and more under these; and so on till the stream is full to the bottom, the weight of those above keeping the others down.  Much of the wood is lost in this way by being frozen into the ice; but the beaver knows that, and cuts plenty.

When a beaver is hungry in winter he comes down under the ice, selects a stick, carries it up into his house, and eats the bark.  Then he carries the peeled stick back under the ice and puts it aside out of the way.

Once, in winter, it occurred to me that soaking spoiled the flavor of bark, and that the beavers might like a fresh bite.  So I cut a hole in the ice on the pool above their dam.  Of course the chopping scared the beavers; it was vain to experiment that day.  I spread a blanket and some thick boughs over the hole to keep it from freezing over too thickly, and went away.

Next day I pushed the end of a freshly cut birch pole down among the beavers’ store, lay down with my face to the hole after carefully cutting out the thin ice, drew a big blanket round my head and the projecting end of the pole to shut out the light, and watched.  For a while it was all dark as a pocket; then I began to see things dimly.  Presently a darker shadow shot along the bottom and grabbed the pole.  It was a beaver, with a twenty dollar coat on.  He tugged; I held on tight—­which surprised him so that he went back into his house to catch breath.

But the taste of fresh bark was in his mouth, and soon he was back with another beaver.  Both took hold this time and pulled together.  No use!  They began to swim round, examining the queer pole on every side.  “What kind of a stick are you, anyway?” one was thinking.  “You didn’t grow here, because I would have found you long ago.”  “And you’re not frozen into the ice,” said the other, “because you wriggle.”  Then they both took hold again, and I began to haul up carefully.  I wanted to see them nearer.  That surprised them immensely; but I think they would have held on only for an accident.  The blanket slipped away; a stream of light shot in; there were two great whirls in the water; and that was the end of the experiment.  They did not come back, though I waited till I was almost frozen.  But I cut some fresh birch and pushed it under the ice to pay for my share in the entertainment.