LEATHER
1043
LEAVENWORTH
that it points out the direction in which a change takes place. It appears to be very nearly equivalent to the very fertile principle that the potential energy of a system tends to become a minimum. Tait defines the "action" of a particle as twice the time integral of its kinetic energy, calculated from an assigned epoch; and then proceeds to state the principle of least action as follows: "If the sum of the potential and kinetic energies of a system is the same in all its configurations, then of all the sets of paths by which the parts of the system can be guided by frictionless constraint to pass from one given configuration to another, that one for which the action is least is the natural one, or requires no constraint."
Leather (leth'er) is made of the skins of animals, prepared by tanning, so as to give them greater strength and toughness, render them unchanged by action of water and stop the tendency toward decomposition. This process is older than can be conjectured, as fragments of Egyptian tanned skins exist which were prepared not later than 900 B. C. There are three methods by which leather is now prepared: first, py tanning or treating with tanbark or other vegetable compounds; second, by tawing or treating with alum, bichromate of potash or other mineral salts; and, third, by shamoying or treating with oils. Of these the first is by far the most used. The skins consist chemically of a fibrous substance, which on being boiled reduces to ordinary gelatine and is called collagen, and of an interfibrous substance called coriin, which cannot be dissolved in water; the combination forms tanno-gelatine, the active principle and base of tanned leather. Although all skins can be tanned, the ones ordinarily used are those of animals which have been killed for other purposes, those of the larger animals being called hides and those of the smaller, skins. The process of tanning a hide for sole leather, described shortly, begins by softening the hide in water, then heating it slowly until the first stages of decay will allow the hair and outer layer of skin to be easily removed, after which it is suspended in a tan-pit containing a weak solution, where it is turned two or three times a day, and removed successively from one pit to another, each containing a stronger solution than the preceding, until the last pit, where the hide may remain for five or six weeks. It is then taken out and beaten to harden it, oiled, and finally rolled to give it a smooth and finished appearance. To dress leather, the flesh-side is smoothed and pared down to give it a uniform thickness. Then it is softened in water and a preparation of tallow and cod-oil is rubbed over it. As the skin dries, the oil sinks into it and renders it smooth and pliable. Morocco and Russia leathers, as now named, are mere names to denote the finish and appearance,
not the place from which they came or a particular kind of skin. The tawing process is used in the preparation of gloveskins, leather for ladies' shoes and skins with the fur left on. Shamoying derives its name from the preparation of the skin of the Alpine chamois, and consists of impregnating the skins with oil by means of stocks and, working it into the leather, but most of the chamois of to-day is split sheepskin.
Leatherstocking Tales, The, are a series of adventures with Indians, by Cooper, in which Hawkeye or Leatherstocking is the central figure. They have become widely popular, especially among youthful readers. Cooper himself said that, if any of his romances were to outlive his own lifetime, it would be this series. The first of these books, The Pioneers, appeared in 1823. The others are The^ Last of the Mohicans, an admirable book in which the interest is maintained from first to last with the most extraordinary power, The Pathfinder, The Deerslayer and The Prairie. In The Last of the Mohicans the white scout, the central figure, is beautifully idealized. He is strong, acute and daring; he is simple and noble; he is cool, versatile, utterly at home with nature in all her moods. The Indian character is idealized, in a way which has been criticised but never forgotten, in the person of Chingachgook and, above all, in Uncas his son. The Pathfinder and The Deerslayer possibly are less exciting than The Last of the Mohicans, the favorite; but as works of art they are admitted to be the best that Cooper has done. " Beautiful" and "grand" are epithets applied by Balzac to The Pathfinder.
Leayenworth (lei/en-w&rih ), an important city of Kansas and the county-seat of Leavenworth County, lies on the right bank of the Missouri River. It nestles in the hollow of the river-bluffs, has wide, macadamized streets and expensive and substantial buildings, and covers an area of about ten square miles. The surrounding country is agricultural, and has fine coal-deposits. The city itself is directly over coal-beds, which have a large yield and furnish employment to many men. Among the manufacturing interests are iron-foundries, shoe, furniture, cracker and bag factories, wagon and buggy works and flour and woolen mills, while mine and mill machinery are made as well as steam-engines. Among the principal buildings are the state orphan asylum, Whittier Library and the Catholic cathedral. The city has good public schools and a high school, besides St. Mary's Academy and the state normal school, and here is the Soldiers' Home. The city was settled in 1854, and has a large river and rail trade, having the service of eight railroads. Two miles from the city is Fort Leavenworth, the headquarters of the department of the Missouri. The United States Infantry and
