D. W. Cammings and P. C. Cambridge, Jr., of North Enfield, . ., have invented a new machine for this purpose. A varying and progressive length of stroke is given to the chisel mandrel or arbor, so that the length of stroke may be gradually increased, as the depth of the mortise increases, and the chisel is thus regularly fed to its work. There are also means employed for rotating the chisel mandrel automatically from the auger arbor. It is a valuable machine.