CALIBRE, or CALIBER, is a technical name for the diameter of the bore of a fire-arm, whether a piece of ordnance or a small-arm. The ordnance from which solid shot are projected are usually denoted by the weight of each shot, as 24-pounder, 68-pounder, etc.; but mortars, and such guns as project shell or hollow shot, are more usually denoted by the C., such as 13-inch mortar, 10-inch shell-gun, etc. The C. of the chief kinds of fire-arm will be noticed under the proper headings; but it may here be observed, generally, that the C. of English ordnance has been greatly increased within the last fifty years, partly by boring up old guns, and partly by casting new.
is that department cf the art of dyeing which takes cognizance of the production of a colored pattern on cloth. It appears to have been first practiced at Calieut iu India—hence the term calico; and the pallampoors, or large cotton chintz counterpanes, which have been manufactured in the East Indies for centuries, are evi dence of the successful practice of the art in that country. From the East Indies, the art spread to Asia Minor and the Levant, thence to Augsburg in Bavaria; from whence, at the beginning of the 18th c., it spread to Alsace ieFrance, to Switzerland, and ulti mately to England and Scotland. The term is strictly applicable to the production of colored patterns on cotton cloth or calico; but as now employed, it includes all the pro cesses followed in the formation of a colored pattern on cotton, linen, worsted, and silk goods, as also mixtures of two or more of these, such as the fabric called de lain, which. is composed of cotton and worsted.
The first operation connected with the printing of cloth is the removal of the surface hairs or minute threads which communicate a fibrous down or nap to the surface of the cloth, and if allowed to remain; would interfere with the uniform application of the colors. The surface down is got rid of by the process of singeing, during which the cloth is drawn over a red-hot iron or copper bar or plate, or through a series of gas jets. The apparatus generally used for hot-plate singeing consists of a furnace surmounted by a metal plate, which is sometimes ridged on the surface. The cloth having previously been joined at the ends, to make a long length, and been placed on a winch-roller, is first brought in contact with roller brushes, which raise the nap on the cloth, then passes over the white-hot metal cylindrical bar, and is wound on to a second winch-roller. The pro cess is repeated twice on the face of the cloth, being the surface to be printed on, and once on the back. Gas-singeing is accomplished by drawing the cloth through brushes, and then over a horizontal pipe, perforated with rows of small boles, or slit from end to end, so that the gas issuing therefrom burns as a narrow sheet of flame. The cloth is not only allowed to come in contact with the burning gas, but the flame is transmitted through the cloth, and a suction-apparatus is often placed immediately above, so as to draw the flame through more effectually. When well singed, the cloth undergoes the process of bleaching (q.v.), and is thereafter calendered. See CALENDERING.
There are several modes of applying the colors to cloth, and these are respectively named-1. The madder style; 2. The padding style; 3. Topical style; 4. Resist or reserve style; 5. Discharge style; and 6. China blue or pottery style. These various processes are at one in being intended to fix upon the cloth the different colors; but they differ from each other more or less in the several steps through which the cloth is passed, though occasionally there is little or no line of separation; and at times the cloth is treated by one method, and subsequently by another style.
The madder style is that in which a certain fixing agent or mordant is printed on the cloth, which is then introduced into the coloring matter in a dye-vat, when the mordant, having an attraction alike for the fiber of the cloth and for the coloring matter, acts the part of glue or paste, and cements the color to the cloth. Originally, madder was the
only coloring substance employed in this style; but nowadays, by far the greater num ber of dyestuffs, vegetable and animal, including cochineal, logwood, etc., are attached to cloth in this manner. The fixing agents or mordants generally employed are different strengths of red liquor (acetate of alumina), iron liquor (acetate of iron), and mixtures of these. These are thickened, with wheat-starch, potato-flour, roasted starch or dextrine, and gum-arabic, so that the mordant may not run when it is placed on the cloth by the pattern-block or by the printing-machine. After the mordant has been imprinted on the cloth, the latter is hung in a warm airy room, where it can easily dry, but where it is at the same time surrounded by a moist atmosphere. The result is, that the mordant is decomposed, the acetic acid is evolved, and the alumina or iron is left attached to the fiber of the cloth in the state of an insoluble sub-salt, which cannot be dissolved by water. As some of the mordant is still left in its original soluble condition, it is neces sary to wash the cloth free from this, else, during the dyeing operation, the soluble part of the mordant would run on to those parts of the cloth not intended to be colored, and thus produce a blotted appearance. To obviate this, the cloth, having undergone the process of drying and aging, is then introduced into a vat containing water, through which is diffused some cow-dung, dung substitute—a preparation of bone ash, sulphuric acid, carbonate of soda, and glue—or bran. The result of this process of (lunging is the removal of the soluble part of the mordant, as also the starch or thickening agent, leav ing the decomposed or insoluble mordant adhering to the fiber. The terms dung-fixing, substitute-fixing, and bran-fixing, have reference to the employment of one or other of these agents at this stage of the operation. When the cloth has been well washed from the dunging, it is introduced into the vat or dye beck containing the coloring matter. The whole is heated by steam-pipes, and the cloth being placed on a sparred reel kept in motion, is repeatedly wound out of the vat, and returned thereto. The result is, that wherever the mordant adhered to the cloth, the coloring matter is attached thereto, and little or no trace of color adheres to the unmordanted parts. The last operation is the clearing or brightening, during which the colored cloth is introduced into warm baths of water containing soda, soap, or, for the more delicate tints, bran, and is thereafter acted on by weak acid solutions. The object is to clear the colors, and at the same time to confer upon them the property of resisting the fading action of the air and sun for a much lono.er time. The different shades of color which can be obtained from the same mad der heck or vat, with different mordants, are very numerous, and include reds, lilacs, purples, chocolates, and blacks. Thus, when a weak solution of red liquor (acetate of alumina) is employed as the mordant, a light red tint is procured; with a stronger alumin ous mordant, a deep red is formed on the cloth; with a more or less dilute solution of iron liquor (acetate of iron), the cloth is colored lilac, violet, or purple; with a strong solution of iron liquor, black is obtained. Indeed, the same piece of cloth stamped in different places with the various strengths of aluminous and iron mordants, and mix tures of these, and immersed in the madder-bath, will be obtained dyed with all the shades mentioned; and in this manner many of the beautiful variegated colored dresses and handkerchiefs are prepared for market.