The device consists of two parts. The bottom is hardwood (generally walnut) with brass rails along the sides and a grooved plate on the working surface. The top part, or roller, is made of the same wood with a matching brass plate. A “pipe” of drug mixture was prepared and placed on the grooves of the pill machine, and by back-and-forth motion of the roller, pills would be formed. Forms producing 18 and 24 pills are most common while those producing small pills or that are provided with a marble slab are quite scarce.