After all the logs are safely sluiced, the chains of the guards are slipped, the rafts are broken up, and these, windlasses and all, follow the logs. Then the boats are put through the sluice. Sometimes, when the dam is high, some of the river-drivers go through in the boats--a dangerous practice, this; for often the bateaux have gone under water, entirely out of sight, to come up below the falls, and more than once have lives been lost in this foolhardy feat. [Illustration: THROUGH THE SLUICE.--A DANGEROUS PRACTICE THIS.] A boom generally passes from three to six dams, and sometimes takes four months to reach the mills. Occasionally the logs become jammed in the rivers, and must wait for more water; if this can be supplied from a lake above, the difficulty is easily remedied. In the spring of 1880, a jam occurred at Mexico in Maine. The logs were piled forty feet above the water and covered an extent of area as large as an ordinary village. This great jam attracted visitors from all parts of the country until the spring freshets of the next year could supply the river with water sufficient to loose them and bear them on their way. ----- At the present time, July, 1880, the jam is still there. I saw the driving and sluicing as I have described it, in May, 1880. It was very interesting.--S. B. C. S.