It is the custom among old male beavers to idle away two or three months of each summer in exploring the neighboring brooks and streams. But they never fail to return in time for autumn activities. It thus becomes plain how, when an old colony needs to move, some one in it knows where to go and the route to follow. I had enjoyed the ways of "our first engineers" for several years before it dawned upon me that their works might be useful to man and that the beaver might justly be called the first conservationist. One dry winter the stream through the Moraine Colony ran low and froze to the bottom, and the only trout in it that survived were those in the deep holes of these beaver ponds. Another demonstration of their usefulness came one gray day. The easy rain of two days ended in a heavy downpour and a deluge of water on the mountainside above. This mountain-slope was still barren from the forest fire. It had but little to absorb or delay the excess of water, which was speedily shed into the stream below. Flooding down the stream's channel came a roaring avalanche or waterslide, with a rubbish-filled front that was five or six feet high. This expanded as it rolled into the pond and swept far out on the sides, while the front, greatly lowered, rushed over the dam. Much of this water was caught and temporarily detained in the ponds, and by the time it poured over the last dam its volume was greatly reduced and its speed checked. The ponds had broken the rush and prevented a flood. Every beaver pond is a settling-basin that takes sediment and soil from the water that passes through it. If this soil were carried down it would not only be lost, but it would clog the deep waterway, the river channel. Deposited in the pond, it will in time become productive. During past ages the millions of beaver dams in the United States have spread soil over thousands of square miles and rendered them productive. Beavers prepared the way for numerous forests and meadows, for countless orchards and peaceful, productive valleys. The Moraine colonists gathered an unusually large harvest during the autumn of 1909. Seven hundred and thirty-two sapling aspens and several hundred willows were massed in the main pond by the largest house. This pile, which was mostly below the water-line, was three feet deep and one hundred and twenty-four feet in circumference. Would a new house be built this fall? This unusually large harvest plainly told that either children or immigrants had increased the population of the colony. Of course, a hard winter may also have been expected.