The above is an invention lately patented in France, by M. Smyers, machinist at Chat- temoue, for sawing and polishing slabs of slate It consists of two circular saws mounted on separate shafts, which dress at the same time with the greatest exactness, the two opposite and parallel sides, and afterwards the two other sides in a perpendicular direction to the former. The slab placed in a truck is approached of its own accord by the movement of the machine as the saws turn round. It follows that the operation is performed very rapidly, and with very little manual labor. This machine is applicable for slabs ot marble and stone.