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horns, they are laid in heaps for one or two days during the summer, and for the space of five or six in the winter. They are next suspended on poles in a smoke-house, or room containing a fire made of wet tan, to induce a slight degree of putrefaction, so that the hair may be easily stripped off. This is effected by spreading the hides on a wooden horse, and extending them a second time on the horse, when all extraneous matters are carefully removed. The hides are next steeped in a pit containing a strong liquor prepared by steeping ground oak-bark in water, after which they are plunged into another pit, containing water powerfully impregnated with oil of vitriol, or with an acid obtained from rye or barley. They are next immersed ir another pit filled with water, a stratum of bark being strewed between each hide, because if this were not done, the bark would act on one side only. In the course of five or six weeks th skins are taken out, and the water, together with the decayed bark, being removed, the pit is a second time filled with ooze, and the hides are again macerated, with similar strata between each, for three months. The same operation is then repeated a third time, after the lapse of three months longer, at the expiration of which they are completely tanned. During this time the hides undergo the process of handling : that is, taking them in and out of the pit repeatedly, and exposing them to the air; for experiments have satisfactorily proved that oxigen and light have a very material and beneficial influence upon the art of the tanner. Being drawn out, they are suspended on poles, when after being compressed by : steel pin, they are beaten with wooden hammers or beetles, to render them smooth, and are then dried for sale.
2. Hides are made from the skins of cows and of lighter oxen in the following manner. The horns are first taken eff, and the hides wasbied and immersed in a pit full of lime water, where they remain for a few days, after which the hair is stripped off. They now undergo various processes, similar to those already detailed, excepting that the ooze is not at first of equal strength, and that the hides are removed every second or third day, for the space of six months, into a stronger liquor, being at length put into a very rich ooze, where they are turned twice every week for two or three months. Thus prepared, they are carried
to another pit, with layers of bark arranged between each side, the process being again repeated for a similar period, when they are taken out and treated in the same manner as the butts. Both species of leather are employed for the soles of pumps, shoes, boots, &c.
3. Skins. This division includes all that is manufactured from the skins of calves, dogs, &c. These are washed in water, and deprived of their hair by the same operation as hides; after removing all uneven and superfluous matters, the skins are soaked in'a pit of water impregnated with the dung of pigeons, for a week or ten days, in order to extract all the particles of lime, grease, &c. They are then treated in a similar manner with the hides, and, in the course of five or six months, will be sufficiently tanned. This, after being prepared by the currier, is used for the upper parts of boots, shoes, &c.
New process. Mons. Seguin in France, and Mr. Desmond in England, have both, very extensively, promoted the new method. By this, oak-bark, having been ground, is digested in water, in vessels for that purpose, and poured off four or five times. The hides, after undergoing the usual preparation, are then immersed.
The tedious process of handling is obviated by suspending the hides over the tan-pit from iron rods. This process employs twenty days in summer and sixty in winter. · Currying. The principal object in this process, is to soften and supple cows' and calves' skins, which are usually employed in making upper-leathers and quarters of shoes, the covers of saddles, coaches, &c. When the skins are brought from the tanner's yard, they are first soaked for some time in common water, and when taken out, are stretched on a smooth wooden horse. The currier scrapes of" with a paring-knife all the superfluous flesh, and immerses them again. They are next put on a wet hurdle, and trampled with the heels, till they become soft and pliant, when they are steeped in train-oil, and afterwards spread out on large tables, and their ends secured. Tallow and oil are rubbed in with a polished stone. The oil could not be rubbed in, unless the hides were well soaked and wetted through with water; the oil occupying the place of the extract, which is evaporated by drying.
The skins are afterwards spread out on large tables, and their ends secured by means of a pummel, an instrument consisting of a thick piece of wood, the lower side of which is full of furrows, or teeth, crossing each other. The skins are then folded, squared, and moved in various directions, to render them supple. The skins are now coloured black, white, red, green, &c. which process is performed either on the flesh or grain side; that on the former, by skinners, and that on the grain or hair side, by curriers. When a skin is to be made white, it is rubbed with chalk, or whitelead, and afterwards with pumice-stone. But, when a black colour is wanted, the skin must be first oiled and dried, then passed over a puff, dipped in water imprega nated with iron, when it is immersed in another water prepared with soot, vinegar, and gum-arabic. Thus it gradually acquires a deep dye, and the operations are repeated till it becomes of a shining black.
Leather is dyed of different colours by various processes,
Water-proof leuther. A rational method of rendering leather water-proof has lately been tried with great succèss. Take a small pipkin or earthen vessel and put in it 3 02. of spermaceti to be meited over a slow fire ; then take three quarters of an ounce of caoutchouc or Indian rubber, cut into thin slices; and the spermaceti will completely dissolve this substance. Add 8 oz. of tallou', 2 02. of hog's lard, and 4 oz. of amber-varnish. The boots or shoes must be rendered dry and warm, and this cement well rubbed in, ihree or four times with a brush.
Morocco leather is made of the skins of goats tanned and dyed in a peculiar manaer by the Turks ; but which processes were originally invented in the kingdom of Mo
English Morocco leather, used so largely for coach-linings, pocket-books, and the best kind of bookbinding is prepared from sheep-skins.
Shagreen is a sort of rough leather, prepared from the skin of the spotted shark. The skin of the fish is first stripped, then extended on a table, and covered with bruised mustard-seed : it is thus exposed to the weather for several days, and afterwards tanned. The best shagreen imported from Constantinople, is of a brownish cast, and very hard ; but when immersed in water, it becomes soft and pliable; and may be dyed of any colour. It is often counterfeited, by preparing Morocco leather in the same
manner as the skin of the fish. This fraud may be easily detected by the surface of the spurious manufacture peels ing or scaling off, while that of the genuine article remains perfectly sound. Shagreen is employed principally in the manufacture of cases for mathematical instruments, watches, &c.
Shammy, or Chamois, is a kind of leather, either dressed in oil, or tanned ; much esteemed for its softness and pliancy. It is prepared from the skin of the chamois, a wild goat, on the mountains of Dauphine, Savoy, Piedmont, and the Pyrenees. Besides the softness and warmth of the leather, it 'has the faculty of bearing soap without hurt. The true chamois leather is counterfeited with common goat, kid, and even sheep-skin.
TAPESTRY. This term is appropriatad to woven hangings of wool and silk frequently raised and enriched with gold and silver, representing figures of men, animals, landscapes, &c. and formerly used to ornament the walls of large rooms. It is supposed that the English and Flemish, who were the first that excelled in 'tapestry, brought the art from some of the croisades or expeditions against the Saracens. The English were the first who established the manufacture of tapestry in Europe. The Gobelins is a celebrated manufactory, formerly established at Paris, for making tapestry, and other furniture. The house where this manufacture was carried on, by two brothers, Giles and John Gobelins, both excellent dyers, and the first who brought to Paris the secret of dyeing that beautiful scarlet colour, is still known by their
In 1667, this place' changed its name from Gobelins, to Hotel Royal de Gobelins, by an edict of Louis XIV.
TOBACCO-Pipes. See Pipes.
TURNING, is the forming of wood, ivory, or other hard bodies into an oval or round shape, by means of a lathe. This art contributes materially to the perfection of many other branches in mechanics. The machine is fixed in a light place, at a sufficient height to allow the turner to inspect his work, without endangering his eyes by the sudden separation of chips. Previously to fixing the wood on the lathe it is rounded with a small hatchet, with a file, or with a plane; and the centres of the surfaces at each
end are 'ascertained : for this purpose, the piece of wood is laid upon a board ; and, after opening a pair of compasses nearly to half the thickness of the piece, one of the legs is attached to the board, and the point of the other brought into contact with one of the ends of the piece to be turned.
Four equidistant arches are then described at the cire cumference of such end, which intersect each other within; and, if these be accurately made, the point of intersection will be the centre. The middle of the opposite extremity is now determined in a similar manner; a small hole is made in both; the points of the puppets are inserted; and the piece firmly fixed, so that it may be easily revolved. The cord is next passed twice round the piece, and adjusted to the strap connected with the wheel : when the rest is placed as closely to the work as possible, the turner moves the wheel, by means of the foot-board ; then presses a gouge, or other chisel, against the wood, in an horizontal direction, and thus, by the steady application of his tools, gives it the requisite form. After having completely turned the work, it requires to be polished either with the skin of the shark, the rough horse-tail, or some other substance adapted to the nature of the material.
VARNISH, is a clear liquid composition, which by age and exposure to the air, becomes hard, without losing its transparency. It is used by painters, carvers, gilders, and artizans, for imparting lastre to their works, while it defends or preserves them from the effects of dust, moisture, and air, Varnishes are of various colours, derived from the ingredients of which they consist; their basis are resins dissolved in fixed oil, volatile oil, or in alcohol ; and are called fat or oily, essential, or spirit varnishes. The fine black varnish obtained from China and Japan, is a resinous juice exuding from a tree called tsi-chu, and which is conjectured to be the cashew-nut tree. All varnishes ought to be secured from the dust. When used, they must be laid on lightly, but quickly, with a clean brush ; the substance thus coated should then be exposed, if in summer, to the heat of the sun, or in a warm room, being covered with a glass case, to exclude dust; and when perfectly dry, they ought to be polished with a smooth piece of