He was trotting hurriedly from stump to stump. Scott hastened to examine one of them and found it very distinctly marked with the print of teeth, as though it had been cut off with a series of gouges with a concave chisel. It was a very neat job.

“Just about two acres cleared clean,” he said, as the doctor puffed up from the swamp. “I did not know they cut down such big trees.”

“Big trees!” the doctor echoed. “There’s a stump down there on the edge of the swamp fifteen inches in diameter. We must have some pictures of this.”

While the Doctor busied himself with the pictures Scott scouted around.

“Look here,” he shouted excitedly, “here are some regular skidways and logging roads.”

The Doctor came on the run. “Yes, sir, well planned ones, too. You see they cut down the tree simply to get the twigs and smaller branches. The latter they haul down these skidways, float to their pond near the house and keep under water so that they can peel them in the winter time. Now let’s go look for the dam. There ought to be a beaver trail down to the swamp.”

He was right. A well beaten trail led them down to the swamp and right to the end of the dam. It was a queer looking structure; a low embankment of dirt and sticks winding away across the swamp, which was dry below the dam and covered with a foot of water above. They walked along the top of the dam pacing the distance as they went. As they neared the stream the dam increased in height to about six feet backing up a corresponding depth of water.

“Two hundred and forty feet,” the doctor said, “isn’t it wonderful?”

“What is it for?” Scott asked.

“You see they had to build it so long on account of the swamp. If the banks of the stream had been steep the dam would have been short. They build it to keep water always around the house, which is built in the pond above the dam. The entrance to it is under water. The wolves can’t get into it. Besides that it gives them a chance to get under the ice for their sticks in the winter. See that big pile of sticks out there in the pond? That is the house. Let’s see if we can get out there.”