During the strange journey across the river, which at that point was fully 200yds. wide, he never for a moment lost his balance, and all the time was whistling cheerily, apparently wholly oblivious of the danger. When the log upon which he stood was swept across the river and close to the opposite shore, he calmly leaped to the bank. He could not swim, which, strange to relate, is the case with fully one-half of the men engaged in the dangerous work of log driving. [Illustration] I am told by a gentleman familiar with the scenes and incidents connected with log driving, that he has frequently seen the drivers cross rivers which were comparatively free of logs, by standing upon a log and with their feet making it revolve quite swiftly, and thus gradually propelling it across the stream. Perhaps it was by observing this operation that the inventor conceived the idea of a roller boat, with which experiments have been made on the Atlantic. When the logs have reached their destination the utility of the log-marks is apparent. When the great mass of logs have been floated to the vicinity of the saw-mills which will manufacture them into lumber, they are brought to a standstill, and preparations are made to separate the logs belonging to different owners. Long "booms" are constructed up and down the river a short distance below the head of the drive of logs. [Illustration] Logs placed end to end, and securely fastened together, form the "booms." The upper end is chained to piers or other immovable objects, which are stout enough to hold the string of logs forming the booms. A river is divided off into a sufficient number of "booms" to provide a separate boom for each firm or individual having logs in the "drive." A strong rope is then stretched across the river a short distance above the ends of the booms. This swings only a few feet above the river, and is for the convenience of the men who separate the logs and float them into the proper boom. The space between the shore and the first boom is exclusively for logs belonging to a certain firm or individual; the space between the first and second booms for those of another, and so on. As the logs are floated down from the stationary "drive" above, which, perhaps, fills the river from bank to bank, and extends up the stream as far as the eye can reach, the men whose duty it is to separate the logs catch them as fast as they are floated down to them, hastily glance at the log-mark, mount the log, and, with the aid of the rope stretched from bank to bank, pull themselves and the log to a point directly above the boom of the owner of the log, and then release it, and permit it to be carried by the current into the proper boom.