as not yet quite dark when Thor came out very quietly into a clearing,
and Muskwa found himself first on the shore of a creek, and then close to a
big pond. The air was full of the breath and warmth of a new kind of life.
It was not fish, and yet it seemed to come from the pond, in the centre of
which were three or four circular masses that looked like great brush-heaps
plastered with a coating of mud.

Whenever he came into this end of the valley Thor always paid a visit to
the beaver colony, and occasionally he helped himself to a fat young beaver
for supper or breakfast. This evening he was not hungry, and he was in a
hurry. In spite of these two facts he stood for some minutes in the shadows
near the pond.

The beavers had already begun their night's work. Muskwa soon understood
the significance of the shimmering streaks that ran swiftly over the
surface of the water. At the end of each streak was always a dark, flat
head, and now he saw that most of these streaks began at the farther edge
of the pond and made directly for a long, low barrier that shut in the
water a hundred yards to the east.

This particular barrier was strange to Thor, and with his maturer
knowledge of beaver ways he knew that his engineering friends--whom he ate
only occasionally--were broadening their domain by building a new dam. As
they watched, two fat workmen shoved a four-foot length of log into the
pond with a big splash, and one of them began piloting it toward the scene
of building operations, while his companion returned to other work. A
little later there was a crash in the timber on the opposite side of the
pond, where another workman had succeeded in felling a tree. Then Thor made
his way toward the dam.

Almost instantly there was a terrific crack out in the middle of the pond,
followed by a tremendous splash. An old beaver had seen Thor and with the
flat side of his broad tail had given the surface of the water a warning
slap that cut the still air like a rifle-shot. All at once there were
splashings and divings in every direction, and a moment later the pond was
ruffled and heaving as a score of interrupted workers dove excitedly under
the surface to the safety of their brush-ribbed and mud-plastered
strongholds, and Muskwa was so absorbed in the general excitement that he
almost forgot to follow Thor.

He overtook the grizzly at the dam. For a few moments Thor inspected the
new work, and then tested it with his weight. It wa