The bear recovered from the crack it had received on the head, thrived in its new mode of life and became one of the curiosities of the park. It became quite tame, permitted a favored few to scratch its head, and only occasionally hurled itself at the wire with an ugly snarl when strangers approached the cage. Different people tried a great variety of food upon it, but nothing seemed to satisfy it so well as the blueberries and fish; of these it never tired.

The capture of the bear had opened up a new field of interest to Scott. He knew the geology of the country thoroughly—could trace the origin of almost every type of pebble to be found in the glacial drift; his dendrology and botany had brought him in touch with all the trees and plants, but the great field of animal life he had completely overlooked. The bear furnished a point of contact, and he grasped the new lead eagerly. He undertook the responsibility of feeding the bear regularly and enjoyed studying his diet and habits. There were many good books on natural history in the library and he soon obtained a pretty good idea of bruin in all his relations to man and beast. He was surprised to see how many new points of interest this study brought out and still more surprised to find how many traces of bear he could find in the woods now that he knew enough to look for them.

Naturally to such an active mind as his, the study and observation of one animal could not help but be an introduction to the other forms of animal life. The deer, wolves, minks, lynx, wild cats, skunks, otter, coons, porcupines, woodchucks, squirrels, chipmunks, frogs, fish, nutes, salamanders, snakes, birds and a host of others he had never dreamed of crowded upon his attention and filled the woods with a new interest. Now that his eyes were opened he could not walk a hundred yards without seeing something to attract his attention. He was beginning to realize how the old woodsman with his knowledge of woods’ life could live for months without human company and never feel lonely.

Greenleaf had long ago discovered this secret, and could help him greatly in his observations. Almost every Sunday when the other fellows were enjoying themselves with the girls at the Lodge these two were canoeing around the lake or tramping through the woods investigating some of the denizens.

As Greenleaf expressed it: “There’s plenty of time to rush the girls when you are cooped up in town and can’t get at the other animals.”

It came about very happily that just at the time when Scott was beginning to get interested in the animals a naturalist came to visit the camp and a geologist came to give the boys some field work. Scott’s thorough knowledge of geology let him out of the class work and enabled him to put in a large part of his time with the naturalist. The trips he made with this interesting man lent him an enthusiasm and gave him many practical hints which carried him easily over the preliminary stage which is apt to be rather discouraging to the uninitiated. It carried him to a point from which he could easily go on alone.

This new friend, Dr. Barnes, was a man of deep reading and wide observation, a Chautauqua lecturer, and a most interesting conversationalist. He had camped all over the north woods studying the habits and watching the antics of the woods creatures. He was as delighted to find a fellow enthusiast no matter how green a beginner, as Scott was to profit by his experience and they became great chums.

The special attraction which had brought Dr. Barnes to that particular place at that time was an opportunity to study the beaver, of which there were a great many in the park. Two pairs placed there ten years before had increased until they populated dozens of lakes and had built some dams of remarkable size. The evidence of their work was everywhere but the beavers themselves seemed to possess a wonderful faculty for keeping out of sight, and Scott was astonished when he tried to look them up in the books to find how little seemed to be known about them.

“Well, Scotty,” Dr. Barnes called to him one morning, “suppose we paddle down to the beaver dam on the west arm and reconnoiter a little? I want to look over the situation there and see if there is an opportunity to stay down there some night and watch them work—for I believe they work at night.”

“Very well, sir,” Scott replied, “I am free today, and shall be delighted to go wherever you suggest.”

“I suggest,” said the doctor, “that we take lunch, explore the place thoroughly, and, if we find it practicable, go back after supper to spend the night.”

They were soon ready to start, and armed with a camera and two axes they paddled swiftly down the west arm. Two deer, standing knee deep in the water, half hidden by the reeds, watched them curiously as they paddled past, but they were bent on rarer game, too intent to turn aside.

“They say the dam is up that little creek; it’s a cedar swamp,” Scott said, “but I don’t know how wet it is.”

“Well, let’s land on that high point just this side of the swamp and we can work in from there. The dam must touch that dry land somewhere.”

“There. The canoe is safe. Shall we take our lunches?” Scott asked.

“Certainly,” the doctor replied emphatically, “one of the first rules of the woods; never get separated from your lunch.”

They climbed the steep bank to a bench which marked a former level of the lake. It had been covered by a good stand of popple, but most of it was now down, apparently thrown by a windstorm. Suddenly Dr. Barnes spied a stump.

“Can it be—” he began excitedly running over to examine the stump. “Yes, sir, that one, that one, that one, everyone of them gnawed down by the beaver.”

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.”

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.

They paddled the canoe over toward the shore again to see if he would recover the branch. After several false starts he took it in tow once more and disappeared with it up the creek. When the canoe was still some distance from the shore they spied another beaver dodging around the lily pads. He was so intent on his own business that he did not seem to notice the silently moving canoe. He was evidently making his evening meal off of the yellow lily buds. Rising head and shoulders above the water, he would devour a bud with great relish, sink silently into the water and come up alongside of another juicy bud. They followed these maneuvers for some time before he took alarm, dived with a loud splash and was seen no more.

They scouted around cautiously but failed to find any more night marauders.

“We’d better go ashore now,” the doctor suggested, “and fix things up for the night. It may get dark before we are ready.”

They pulled the canoe up on the marshy shore and made their way up the stream to the spot they had picked in the morning. The mound of moss proved to be none too large, but the blankets were finally arranged so that they thought they could spend the night in comparative comfort.

“Now for a hole in the dam,” the doctor said, with suppressed excitement. “Where’s the ax?”

They soon found that a pick would have been more effective. The dam was built even better than they had thought. The sticks were woven together and plastered with a solidity that astounded them. A breach some three feet long and a foot deep was finally made, and the water came pouring out with a rush which must have appalled the beavers.

“There,” said the Doctor panting from his exertions, “that ought to bring them all to the rescue. We must keep very still and wait patiently.”

“Do you think they can smell us here?” Scott asked anxiously. “We are pretty close to the break.”

“No, I don’t think so; most of these water animals rely more on sight and hearing than on smell. They may be suspicious for a while, but they will have to fix it for fear of having their pond drained.”

It did not take the beavers long to discover the break in the dam. The watchers had scarcely settled themselves on their blankets when they heard the distant plunk of a diving beaver in the pond. There was a moment of tense silence and then another plunk nearer.

“Here they come,” the doctor whispered excitedly. “Keep quiet.”

The approaching beaver evidently wanted to investigate the leak, but had no idea of being drawn into an ambush. He circled cautiously around at a distance, diving nervously at short intervals, till, finally assured that there was no danger, he swam boldly up to the breach and nosed around it. They could see the faint glimmer from the little roll of water he pushed along in front of him and once he passed so close to them that they could hear his heavy breathing. Then he swam quietly away.

“That must be the watchman sent to reconnoiter,” the Doctor explained. “He has gone back to report on the break.”

He must have made a very lengthy report or had some trouble in convincing the others, for it was a full hour before they heard anything from him. Then once more they heard the distant “plunks.” Much to their disappointment he came alone. He repeated the same performance as before and disappeared once more.

“He must have forgotten some of the details,” Scott muttered.

Another hour of waiting and he came again. He seemed worried over the escaping water but showed no inclination to repair the dam.

The next hour it was the same thing. “He must patrol this place all night,” Scott suggested. “Do you notice that he strikes the hour almost to the dot?”

“Yes,” the doctor murmured, a little sleepily. “They must come to repair that dam pretty soon. We ought to have made the hole deeper.”

It grew cold in the swamp and each hour seemed colder than the preceding one. The dismal squawk of a night hawk or the honk of a passing blue heron sounded occasionally above the monotonous flowing of the water. An owl seemed to be hooting fun at them from a neighboring tree—for he always started up just after the sentinel had made his round, and along toward morning the occasional scream of a coon just returning from his night’s marauding, pierced the stillness. The crowded quarters on the little mound of moss were very hard on cramped muscles and the lack of industry on the part of the proverbially busy beavers was thoroughly disappointing. Scott was beginning to feel his enthusiasm in the beavers oozing away.

The dawn, that chilling interval between night and morning, was stealing upon them and soon the streaks of light began appearing in the eastern sky.

The Doctor stretched himself as much as he dared without getting his feet in the water and sat up shivering. “I guess we have seen about all we are going to see this trip,” he said despondently. “We might as well go down here on dry ground where we can stretch ourselves and cook breakfast.”

“Don’t you suppose they are going to fix that blooming dam sometime?” Scott asked in disgust.

“Surely they’ll fix it,” the doctor replied confidently; “maybe they work in the daytime. We’ll come back again sometime, break the dam wide open, and hide on a platform in the trees. Maybe that would get them.”

Scott made a mental resolve that he would not make one of the party in the tree, but the little doctor’s ardor was so little dampened by the failure that he soon felt ashamed of himself.

“After all,” the doctor said reassuringly as they paddled back to camp, “we did not fail altogether. All scientific facts are collected slowly, one by one, and each new one is so much added to the sum of human knowledge. We have seen a beaver patrolman on his beat—even had some water splashed on us by him—and that’s more than any other scientist I know can say.”