SILK MANUFACTURE. This may be divided into two branches: —1, the production of raw silk ; 2, its filature and preparation in the mill, for the pur poses of the weaver and other textile arti sans. The threads, as spun by the silk worm, and wound up in its cocoon, are all twins, in consequence of the twin ori fice in the nose of the insect through which they are projected. These two threads are laid parallel to each other, and are glued more or less evenly to gether by a kind of glossy varnish, which also envelopes them, constituting nearly 25 per cent. of their weight. Each ulti mate filament measures about of an inch in average fine silk, ana the pair measures of course fully of an inch.
The raw silk, before it can be used in weaving, must be twisted or thrown, and may be converted into shingles, tram, or organzinc. The first is produced merely by twisting the raw silk, to give more firmness to its texture. Tram is formed by twisting together, but not very closely, two or more threads of raw silk, and usually constitutes the weft or shoot of manufactured goods. Organzine is prin cipally used in the warp, and is formed by twisting, first, each individual thread, and then two or more of the threads, thus, twisted, with the throwing-mill. The silk, when thrown, is called hard silk, and must be boiled, in order to discharge the gum, which, otherwise, renders it harsh to the touch, and unfit to receive the dye. After boiling about four hours in soaped water, it is washed in clear water, to discharge the soap, and is seen to have acquired that glossiness and soft ness of texture which forms its principal characteristic. The yarn is now ready for weaving.
Silk-worms are fed, in France, on the leaves of the white mulberry, planted in hedge-rows, as pollards, and raised from seeds by nurserymen. The eggs are hatched in rooms, heated to 721° b. One ounce of eggs consume 1 cwt. of leaves, and produce from 7 to 9 lbs. of raw silk, which is wound off the cocoons by wo men and children. The season is May.
The silk-worm is now propagated in the United States, and even so far north as 45° there is a mulberry-orchard of 100 acres, and considerable produce of silk, 81 dollars per lb.
Silk-worms may be reared with success on the leaves of the seorsonent, or with neer tartarium.
Satin is a silk twill of peculiar descrip tion, the soft and lustrous face of which is given by keeping a largo proportion of the threads of the warp visible. When first taken out of the loom, satins are sometimes flossy and rough ; and they are dressed by being rolled on heated ,finders, which operation gives the bril hunt lustre.
Watering silk is performed by passing two pieces of silk placed lengthways, one on the other, between two metallic rol lers : the different parts are thus subject ed to different degrees of pressure, from which the wavy appearance results.
Silk is embossed by passing the plain stuff between rollers; the surfaces of which contain the desired pattern on one cylinder, and on the other sunk, so that the eminences of the one coincide with the depressions of the other.
This business, like all other branches of manufacturing industry, has struggled, in this country, against adverse fortune, and counteracted difficulties not contem plated by its early founders. But we be lieve for the past year or two the manu facture of sewing silk has been highly prosperous, and several new mills have been erected in different sections of the country. In Tolland county, Conn., there arc six factories, which respectively turn off the following amounts of sewing silk and twist per annum :— Vyse & SM.', at Willington, 12,000 pounds.
Burford & Butler, at Mansfield, 5,000 " William Atwood, " " Zalmon, Storrs & Son, 2,000 " J. & E. llovey, 1,500 " Chaffee & Co., ti In addition to these, we will enumerate the remaining establishments which we know to be in operation in different sec tions of the United States, with a proba bly correct estimate of the amount of goods manufactured per annum : Cheney & Brothers, Manchester, Conn.,.... . . ... . .......... 16,000 pounds.
A. 11. Jones, do. do.,.... 2,500 " Sowerhy & Co., Northampton, Mass , 7,000 " Joseph Conant,_ do. do., 3,5t* " --, New Haven, Conn , 1,500 William Dale, New York city " Murray & Co., Patterson, N. 4 10,000 " Livesy & Co., Canton, Mass,, 2,000 " B. & A. Hooley, Philadelphia, 3,030 " Brown & Co., Louisville, Ky., 1,500 "