"Papa," demanded Bobby, "I don't see how you tell your logs from Mr. Proctor's or Mr. Heinzman's or any of the rest of them." Mr. Orde turned, extending his hand heartily to his astonished son. "You're all right, Bobby!" said he. "Why, you see, each log is stamped on the end with a mark. Mr. Proctor's mark is one thing; and Mr. Heinzman's is another; and all the rest have different ones." "I see," said Bobby. The road now led them through a small grove of willows. Emerging thence they found themselves in full sight of the booms. For fifty feet Bobby allowed his eyes to run over a scene already familiar and always of the greatest attraction to him. Then came what he called, after his Malory, the Stumps Perilous. Between them there was but just room to drive--in fact the delicate points of the whiffle tree scratched the polished surfaces of them on either hand. Bobby loved to imagine them as the mighty guardians of the land beyond, and he always held his breath until they had been passed in safety. Shying gently toward each other, ears pricked toward the two obstacles, the horses shot through with pace undiminished and drew up proudly before the smallest of the group of buildings. Thence emerged a tall, spare, keen-eyed man in slouch hat, flannel shirt, shortened trousers and spiked boots. "Hullo, Jim," said Mr. Orde. "Hullo, Jack," said the other. "Where's your chore boy to take the horses?" "I'll rustle him," replied the River Boss. Bobby drew a deep breath of pleasure, and looked about him. From the land's edge extended a wide surface of logs. Near at hand little streaks of water lay between some of them, but at a short distance the prospect was brown and uniform, until far away a narrow flash of blue marked the open river. Here and there ran the confines of the various booms included in the monster main boom. These confines consisted of long heavy timbers floating on the water, and joined end to end by means of strong links. They were generally laid in pairs, and hewn on top, so that they constituted a network of floating sidewalks threading the expanse of saw-logs. At intervals they were anchored to bunches of piles driven deep, and bound at the top. An unbroken palisade of piles constituted the outer boundaries of the main boom. At the upper end of them perched a little house whence was operated the mechanism of the heavy swing boom, capable of closing entirely the river channel. Thus the logs, floating or driven down the river, encountered this obstruction; were shunted into the main booms, where they were distributed severally into the various pocket booms; and later were released at the lower end, one lot at a time, to the river again. Thence they were appropriated by the mill to which they belonged.