The accompanying engraving represents an improved machine for sharpening machinists' tools of all kinds. The corundum wheel, the grade of which varies to suit the kind of work to be done, runs in water, thereby avoiding all danger of drawing the temper from hardened tools. A wheel made of this material cuts faster than the ordinary grindstone, is more accurate, and much cleaner. This grinder occupies a space only 12 by 22 inches. No water flies from the wheel, as it is covered with a hood, except where the grinding is done. The manufacturers of this grinder—the New York Supply Company (limited), of 50 and 52 John Street, New York city—have adopted a special corundum wheel, which, by reason of its porous nature, is constantly moist, and, inconsequence, all danger of drawing the temper of the tools is obviated.