were conspicuous. The beaver now went very cautiously,
sniffing the air for any hint of peril. After winding along for some
twenty or thirty yards, the new canal shoaled out to nothingness
behind a screen of alder; and here, in a mess of mud and water, the
beaver found one of his comrades hard at work. There was much of the
new canal yet to do, and winter coming on.

The object of this new ditch was to tap a new food supply. The food
trees near enough to the pond to be felled into it or rolled down to
it had long ago been used. Then the straight canal across the meadow
to the foot of the upland had opened up a new area, an area rich in
birch and poplar. But trees can be rolled easily down-hill that cannot
be dragged along an uneven side-hill; so, at last, it had become
necessary to extend the canal parallel with the bottom of the slope.
Working in this direction, every foot of new ditch brought a lot of
new supplies within reach.

[Illustration: "STICKY LUMPS, WHICH THEY COULD HUG UNDER THEIR CHINS."]

The extremity of the canal was dug on a slant, for greater ease in
removing the material. Here the two beavers toiled side by side,
working independently. With their teeth they cut the tough sod as
cleanly as a digger's spade could do it. With their fore paws they
scraped up the soil--which was soft and easily worked--into sticky
lumps, which they could hug under their chins and carry up the slope
to be dumped upon the grass at the side. Every minute one or the other
would stop, lift his brown head over the edge, peer about, and sniff,
and listen, then fall to work again furiously, as if the whole future
and fortune of the pond were hanging upon his toil. After a
half-hour's labour the canal was lengthened very perceptibly--fully
six or eight inches--and as if by common consent the two brown
excavators stopped to refresh themselves by nibbling at some succulent
roots. While they were thus occupied, and apparently absorbed, from
somewhere up the slope among the birch-trees came the faint sound of a
snapping twig. In half a second the beavers had vanished noiselessly
under water, down the canal, leaving but a swirl of muddy foam to mark
their going.

CHAPTER IV

Night Watchers

WHEN the Boy came creeping down the hillside, and found the water in
the canal still muddy and foaming, he realized that he had just missed
a chance to see the beavers actually at work on their ditch-digging.
He was disappointed. But