When the water is too shallow on any part of a stream to float the logs, dams are constructed to flow the water back, with gates which can be opened and shut at pleasure, and either through the apertures of the gates or sluice-ways made for the purpose, the logs are run. This dam answers the same purpose in raising the water to float the logs below as above, on the brook. Shutting the gates, a large pond of water is soon accumulated; then hoisting them, out leaps the hissing element, foaming and dashing onward like a tiger leaping upon his prey. Away the logs scamper, reminding one of a flock of frightened sheep fleeing before the wolf. Some logs are so cumbersome that they remain unmoved, even with this artificial accumulation of water. In such cases, embracing the moment when the water is at its highest pitch, in we leap, and, thrusting our hand-spikes beneath them, bow our shoulders to the instrument, often stooping so low as to kiss the curling ripples as they dance by. In this way, sometimes by a few inches at a time, and sometimes by the rod, we urge them over difficult places; while, in connection with the annoyance of very cold water, broken fragments of ice mingle in the melée, imposing sundry thumps and bruises upon the benumbed limbs of the enduring river-driver. In some places, on low, swampy land, a body of water accumulates several rods wide, and from three to ten feet deep. Here the logs, as if to play "hide and seek," run in among the bushes, giving infinitely more trouble than amusement. Under such circumstances, it becomes necessary for the men to keep on the logs most of the time; and as logs roll very easily in the water, and are often extremely slippery, it requires the balancing skill of a wire-dancer to keep on them; and often some luckless wight, whether he will or no, plunges over head and ears into the flood as he is whirled from the back of some ticklish log; and, however unwelcome to himself, no sooner is his head above water than he hears the wild woods echo the jeering laugh of his more fortunate comrades.