In the meantime a barely perceptible motion was communicating itself from one particle to another through the center of the jam. A cool and observant spectator might have imagined that the broad timber carpet was changing a little its pattern, just as the earth near the windows of an arrested railroad train seems for a moment to retrogress. The crew redoubled its exertions, clamping its peaveys here and there, apparently at random, but in reality with the most definite of purposes. A sharp crack exploded immediately underneath. There could no longer exist any doubt as to the motion, although it was as yet sluggish, glacial. Then in silence a log shifted--in silence and slowly--but with irresistible force. Jimmy Powers quietly stepped over it, just as it menaced his leg. Other logs in all directions up-ended. The jam crew were forced continually to alter their positions, riding the changing timbers bent-kneed, as a circus rider treads his four galloping horses. Then all at once down by the face something crashed. The entire stream became alive. It hissed and roared, it shrieked, groaned and grumbled. At first slowly, then more rapidly, the very forefront of the center melted inward and forward and downward until it caught the fierce rush of the freshet and shot out from under the jam. Far up-stream, bristling and formidable, the tons of logs, grinding savagely together, swept forward. The six men and Bryan Moloney--who, it will be remembered, were on top--worked until the last moment. When the logs began to cave under them so rapidly that even the expert rivermen found difficulty in “staying on top,” the foreman set the example of hunting safety. “She 'pulls,' boys,” he yelled. Then in a manner wonderful to behold, through the smother of foam and spray, through the crash and yell of timbers protesting the flood's hurrying, through the leap of destruction, the drivers zigzagged calmly and surely to the shore. All but Jimmy Powers. He poised tense and eager on the crumbling face of the jam. Almost immediately he saw what he wanted, and without pause sprang boldly and confidently ten feet straight downward, to alight with accuracy on a single log floating free in the current. And then in the very glory and chaos of the jam itself he was swept down-stream. After a moment the constant acceleration in speed checked, then commenced perceptibly to slacken. At once the rest of the crew began to ride down-stream. Each struck the caulks of his river boots strongly into a log, and on such unstable vehicles floated miles with the current. From time to time, as Bryan Moloney indicated, one of them went ashore. There, usually at a bend of the stream where the likelihood of jamming was great, they took their stands. When necessary, they ran out over the face of the river to separate a congestion likely to cause trouble. The rest of the time they smoked their pipes.