In England, curried leathers are generally sold by weight, which leads to the use of glucose and other materials to add to the weight. In America, all upper leathers are sold by measure, and this is now ascertained by a very ingenious machine (Fig. 58). The skin is laid on a latticed table, and a frame, from which rows of bullets are suspended, is let down upon it. The total weight of the frame is indicated by a spring balance, and as the bullets which are over the skin are supported by it, the diminution of weight indicates the measurement. Several modified forms of this machine are now made. CHAPTER XIV. ENAMELLED, PATENT, OR JAPANNED LEATHER. These are terms used to designate those leathers, whether of the ox, the horse, the calf, or the seal, which are finished with a waterproof and bright varnished surface, similar to the lacquered wood-work of the Japanese. The name "enamelled" is generally applied when the leathers are finished with a roughened or grained surface, and "patent" or "japanned" are the terms used when the finish is smooth. Though generally black, yet a small quantity of this leather is made in a variety of colours. In America, large thin hides are principally used for the purpose. They are limed and bated in the usual way, stoned after bating, and tanned with hemlock and oak barks in a paddle tumbler, which is run for 10-15 minutes in each hour. When one-third tanned, they are levelled on the flesh, and split with the belt-knife splitter, Fig. 52. After splitting, the portions are drummed with strong gambier liquor for 1/4 hour, and then tanned out with bark. The grains are scoured with the Fitzhenry or Lockwood machine (Figs. 53 and 56). They are then lightly oiled and stretched on frames which can be enlarged by screws or a sort of knuckle-joint at the corners. When quite dry, they are grounded with a mixture of linseed-oil with white lead and litharge, boiled together and thickened with chalk and ochre. This is dried in closets heated by steam, into which the frames are slid face downwards, the heat being gradually increased from 80° to 160° F. (27° to 71° C.). If it be desired to employ a higher temperature, the leather is first saturated with a solution of 2 oz. each of borax and alum in 1 gal. water, when temperatures of 230°-250° F. (110°-120° C.) may be used. The remaining treatment is much as above described, but a little turpentine is used to make the paint work freely. The final varnish is composed of 20 parts spirit of turpentine, 20 linseed oil, 10 thick copal varnish, and 1 of asphaltum or other colouring material. This must be mixed 2-3 weeks before use, and applied with a brush.