Page:Miscellaneous Papers on Mechanical Subjects.djvu/138

 with three long holes, lying close together, and having their ends sharpened like the cutting edges of a hollow punch. A line of fifteen tubular cutters is thus formed, and motion is given to the horizontal bar, in which they are fixed by a crank, which impels them against the timber. This is depressed at each stroke sufficiently to allow each cutter to cut out its spill, which passes through and tails out behind.

The cost of this machine would not exceed 20l., and when the number of matches, all nicely rounded, which it is capable of producing, is contrasted with the number which could be produced by a hand instrument in the same time, it will serve as a simple and striking illustration of the advantageous employment of machinery to do the work of man.

31. Last and Boot-tree Manufactory.—A machine, constructed on Blanchard's principle, is used for making lasts.

A pattern last, and the block of wood from which another last is to be cut, are fixed upon, and revolve round, a common axis, being connected with the centres of a headstock fixed on a frame made to oscillate from below. As the pattern revolves it is kept continually pressed against a knob of iron by a spring, and as the block of wood revolves it is shaped by a circular