Page:Miscellaneous Papers on Mechanical Subjects.djvu/137

 boards which are tongued and grooved by what is called a "matching machine," and then put together as that operation is finished.

The tonguing and grooving cutters are fixed on horizontal axes, and the workman passes the boards alternately over one or the other, as the sides require to be tongued or grooved.

Other varieties of planing machines are also in use, known by the names of their different inventors; some of them have fixed, vertical, or horizontal cutters, others vertical or horizontal revolving cutters, and various other combinations, according to the purposes for which they are intended.

30. Spill or Match-making Machine.—This machine makes 900 round spills, 15 inches long, ⅛ inch diameter, per minute; so that if each spill were cut into five matches, each 3 inches long, 4,500 would be produced every minute.

The spills are cut from pieces of straight-grained timber, made of such a length as to pass between two grooved feeding rollers, which hold the timber, so that its under surface is level with the lowest parts of a row of tubular cutting tools, or long sharp-edged punches.

The cutting tools are thus arranged:—Five pieces of steel are fixed side by side in a horizontal bar. Each piece of steel is perforated