THE APPLICATION OF MACHINERY.

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end of the slide to the upper end, where the treeswere introduced, workmen were posted at regulardistances, and as soon as every thing was ready,the workman at the lower end of the slide cried outto the one above him, “ Lachez" (Let go). The crywas repeated from one to another, and reached thetop of the slide in three minutes. The workmen atthe top of the slide then cried out to the one belowhim, “ II vient” (It comes), and the tree was in-stantly launched down the slide, preceded by thecry which was repeated from post to post. As soonas the tree had reached the bottom, and plungedinto the lake, the cry of Lachez was repeated asbefore, and a new tree was launched in a similarmanner. By these means a tree descended everyfive or six minutes, provided no accident happenedto the slide, which sometimes took place, but whichwas instantly repaired when it did.

“ In order to shew the enormous force which thetrees acquired from the great velocity of their de-scent, M. Rupp made arrangements for causing someof the trees to spring from the slide. They pene-trated by their thickest extremities no less than fromeighteen to twenty-four feet into the earth ; and oneof the trees having by accident struck against theother, it instantly cleft it through its whole length,as if it had been struck by lightning.

“ After the trees had descended the slide, they werecollected into rafts upon the lake, and conducted toLucerne . From thence they descended the Reuss,then the Aar to near Brugg, afterwards to 'Waldshut by the Rhine, then to Basle , and even to the seawhen it was necessary.

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