The first step taken with raw silk is to separate the " book '' or " moss " into knots, and sort these into lots according to their respective fineness, as well 8.s can be judged by the eye. This separation is, however, a very imperfect one, as the unaided eye is scarcely equal to discrimi nating between the differences in the thickness uf the threads ; and in addition, there are many knots that contain both fine and coarse thread, ehang,ing to one or the other in the space of a few yards. After this preliminary, the hanks are dipped for a short time in a solution of soap and water, to soften the gum upon the fibre, which renders it more pliable and easy to wind, for which operation it is then ready.
Wolding.—The winding-machine, Fig. 1226, is generally arranged in the swifts to take either Italian, Chinese, or Japanese reeled silks. It is a very simple machine, consisting of little more than the framework, the swifts, and a roller carrying friction-drurne, on which the bobbins for the reception of the silk revolve. These, being duplicated, render the machine double. Fig. 1227 shows a section of the working parte. The swift a is composed of a hub or nave of wood, into which are inserted aiX pairs of thin lauarwooti ruds b. Each pair of rods is connected near the top by thin cords ; to keep the latter at proper tension, a wedge c is put below the cords, and presses the laneewood rods apart. Both cords and rods can be easily adjusted to receive any size of hank. Each swift has a small weight suspended upon the hub, in order to prevent its too rapid revolution, and to impart the requisite tension to the thread in process of winding. The bobbins are fixed upon spindles having heads or small rollers, aud are actuated by friction-wheels d. A slot e is prepared for the spindle when out of contact with the friction-driver. Fig. 1228 exhibits another form of winding-machine.
A " slip " or hank having been put upon the swift, the end of the thread is found, and the winder, wetting it in her mouth, casts it upon the bobbin, to which it adheres ; this being placed upon the driver, the winding commences, the thread having been previously in serted iuto the curl or ring of the guide-wire, fitted into the traverse rail, whose lateral movement winds the thread regularly upon the bob bin. When the bank is wound off, or the thread breaks, the end is joined to that upon the bobbin by a peculiar knot formed to prevent slipping in subsequent operations. The guide-rail or traverse-bar is operated by elliptical wheels, or heart-shaped cams, in order to make a bobbin of a good form. To pre
vent waste of material and loss of time, the winding is arranged so that each successive layer shall obliquely cross the threads of the preceding one. Winding-frames generally contain 30-10 swifts to each side of the machine.
Cleaning. — The cleaning - ma chine, Fig. 1229, which is often called the redrawing frame, to which the bobbins from the winding-frame are now conveyed, is of similar construction to the preceding machine. For the swifts of the winding-frame, is substituted a bobbin-board, fitted with pegs to hold the bobbins; whilst in place of the guide-w ircs of the traverse-rail, the thread passes between two vertical steel blades, whose edges are set so closely together as to detect and arrest any knots, slubs, or other defeets of a gross kind tl3at would interfere with the perfection of the subsequent stages of the work. The distance between the edges of these blades can be adjusted with great nicety by means of screws. Fig. 1230 shows the working parts in section. The bobbin a from the winding-machine is placed upon the pin iu the hoard, so as to allow of easy revolution in unwinding. The thread is conducted over the carrier-rod b, next passing through the cleaner or vertical blades c, and thence upon the bobbin d, actuated as before by the friction-wheel e. The cleaner is fixed in the traverse-bar or guide-rail. An enlarged front view of the cleaner is shown at f.
Cleaning is not the only purpose of this process ; an object of equally great importance is the " sizing" of the silk, a word implying a very different process from that which the same term indicates when used in oonneotion with the cotton trade. It means the still further elimination of the irregularities of raw Bilk, enabling the manufacturer to produce an even fabric. As the winding proceeds, the attendant is carefully observing the threads, and when one of these begins to deliver a thread finer than required, it is broken off, and the bobbin is moved to the right ; if a coarse thread comes off, it is similarly moved to the left. When the process is completed, the silk is thus assorted into two sizes, which are marked firsts and seconds. When it is desired to secure the most perfectly even threads, this process is repeated several times, though all of them constitute but a very imperfect remedy for careless reeling from the cocoon.