LEATHER SUBSTITUTES. Owing to the increasing demand for leather in the facture of shoes, belting and harness, the ply of thin sections of hides suitable for upholstery, bookbinding, travel goods, etc., has steadily decreased and its cost increased. The result has been the introduction of various leather substitutes. These are of two chief classes : (1) those which imitate the appearance of leather, and (2) those which also duplicate its general characteristics and durability. In the first class there are embossed papers, papier macho, oilcloth and light weight cloths thinly coated with rubber, linseed oil compounds and soluble cotton. In the second class there are strong, thick fabrics heavily coated and em bossed with rubber or linseed oil, or soluble cotton compounds. The latter successfully duplicate the coloring, feeling and embossed graining of the best hide leather. While none has at this writing been made quite the equal of real grain leather, the best grades of leather substitutes- are generally more durable than i what is known in the trade as "split leather?' which is composed of the weaker fleshy por tions of the thick hide, split away from the grain or hair side to produce thin upholstery leather.
Split leather, coated with soluble cotton, and embossed in various grains, is really a variety of leather substitute, its base of tanned fleshy substance being about half as strong as the better grades of leather substitutes having, heavy fabric bases. Split leather, commonly sold as "genuine leather,° is the chief cause of disappointments in leather upholstery as it does not compare in wearing qualities with grain leather. The fabric substitutes most used are coated with a jelly consisting chiefly of soluble cotton in solution which carries the pigment required to produce the desired color. The jelly in a fluid condition is spread on the cloth while the latter is moving over rollers.
It is scraped to a thin coating by a knife set in the machine. Each coating is quite thin, suc cessive coatings being applied to build up the desired body. The solvent evaporates during the coating process, leaving the jelly in the form of a tough, flexible film of pyroxylin firmly anchored to the cloth. The plain coated cloth is then embossed by hot rolls or plates bearing the desired grain, which is the last stage of the process. Two-color effects such as Spanish or Moorish finish are obtained as in the real leather process by flooding the grained surface with a darker coating and wiping it off in spots to give a shaded or toned effect and to show a darker color in the ((val leys° than on the "hills.° Leather substitutes are now extensively used for upholstering au tomobiles, furniture, carriages, etc., and in industries ndustries formerly dependent on leather.
or TRUNK BACK, a rare marine turtle of the tropical seas (Sphargis coriacea), which has a leathery case instead of a shell. It is the largest of existing Chelonia, known specimens having a case four feet in length, and a live-weight of not less than 1,000 pounds. When young its case is thin, soft and flexible, but as age ad vances the jacket becomes stiffened by the formation within it of great numbers of little adjoining bony plates and the exterior shows strong longitudinal ridges. These turtles are powerful swimmers and wander throughout the oceans, feeding upon jellyfishes, crusta ceans, cuttlefishes and other animal food. Late in the summer it seeks some sandy shore or islet, where the female buries her eggs after the manner of other sea-turtles. These eggs are good to eat, but the flesh of the animal is not of good taste, and is said to be unwhole some. Much interesting discourse upon the curious structure, relationships and ancestry of this declining race may be found in Gadow's and Reptiles) (London 1901).