By walking fallen trees and wading shallow bars they finally reached the house. It was some fifteen feet across and protruded about four feet above the water. It was built of sticks—all of them providently peeled beforehand—from an inch to three inches in diameter, the whole plastered thickly with mud. It seemed perfectly solid. There were a few tracks in the mud and a whimpering such as might be made by small pups came from the inside, but no beavers were to be seen. They retraced their way to the dam.
“Right there,” the doctor said, pointing to a mound of comparatively dry moss, “we could spend the night quite comfortably. I believe that if we break a hole in the dam so that they can hear the running of the water they will come to fix it up.”
They made their way down the stream. There were several other dams which had apparently been abandoned, all short, but one of them higher than the new one. Just before they reached the lake Dr. Barnes was delighted to find an old abandoned house.
“Now,” he exclaimed excitedly, “we’ll see what it’s like inside.”
The solidity of the structure was wonderful, but by dint of considerable hard work with the axes they cut away half of the house, showing the interior in cross section. It was some time before Scott had a chance to inspect it himself for the hole was no sooner opened than the doctor crawled into it head first; spasmodic wriggling of his legs and a series of muffled exclamations alone told of the state of his emotions. He stayed so long that Scott began to fear that he had moved in there to live. He finally wriggled out very red in the face, and very jubilant.
“Why don’t you look in there?” he asked. “You can see just how they live.”
Scott did not waste any time explaining why he had not looked in, but crawled eagerly into the muddy opening. Much to his surprise he found the floor of the house well above the level of the stream and perfectly dry. The roof of the house was arched up with great skill leaving an opening in which a good-sized man could curl up very comfortably. On two sides there were tunnels leading down to small dirt landings almost on a level with the surface of the water. From these the beaver could slip conveniently under the water, still within the house, and swim out through a submarine passage. It was certainly a very ingenious arrangement—for they had all the advantages of living on land and at the same time were protected absolutely from the attacks of all land animals. The floor was covered with fish bones, which Scott learned later had probably been left there by the mink who had made use of the house after its abandonment by the original inhabitants—for the beavers themselves do not eat fish.
No sooner had Scott wriggled out than the doctor crawled laboriously in again with a pencil and envelope in his teeth to draw a sketch of the interior. This completed and several photographs taken of the house from all angles, they ate lunch, traced out the boundaries of the cuttings on both sides of the swamp and paddled home to prepare their outfit for a night in the wet moss. Dr. Barnes was all enthusiasm.
The other boys had no desire to share in the expedition, but they were immensely interested in a way and shouted bits of advice and sarcastic sympathy after the canoe as long as it was in range.
The long twilight gave them plenty of time, and they sneaked the canoe along the edge of the lily pads in hope of catching some of the beavers out foraging—for it was the time of day when they were most often seen. As they approached the cedar swamp they observed a green popple branch moving mysteriously and swiftly across the surface of the lake. Closer observation showed that it was being vigorously pushed along by an energetic beaver. They gave chase to see what he would do. He was evidently loath to give up the prize, for he only swam the faster, throwing quite a swell like a small tug boat. Finally the pursuit became too hot for him and he abandoned the branch, diving under the surface with a splash. Several times he came up to reconnoiter, diving again almost instantly. Each time he dived he struck the water a blow with his broad flat tail which sent his head under with a jerk and made a report easily heard a half-mile away over the still water.