A very soft, fine, bright thread, the production of different species of caterpillars; but the bombyx mori, or silk-worm, is chiefly cultivated for this purpose; it is a native of China, and the culture of silk in ancient times was entirely confined to that country.
The natural history of the silk-worm forms a subject highly interesting and curious; but the extraordinary changes which the animal undergoes, as well as its manner of spinning its ball or cocoon, having probably fallen under the actual observation of most of our readers, we shall pass over this part of our subject, and proceed to the business of winding, throwing, and weaving.
In those countries where silk forms an important article of commerce, the cultivators, or those who rear the insects, do not wind off the silk themselves, but sell them to others, who make the operation of reeling a distinct business. The single filament, or thread of silk, as produced by the worm, is of such extreme tenuity as to be totally unfit for the purposes of the manufacturer. Therefore, in winding it off, several of the cocoons are immersed in warm water, to soften the gum with which the silk is naturally connected; their several ends are then joined and reeled off together; and, by the adhesiveness of the gum, are thus formed into one smooth even thread. When the thread of any cocoon breaks, or comes to an end, its place is supplied by a new one, which is simply laid on the main thread, to which it adheres by its gum; and, owing to its extreme fineness, it does not occasion the least perceptible uneven-ne3s in the place where it is united. In this manner of joining the separate filaments, a thread may be made of any length.
The apparatus for reeling consists merely of an open kettle of water, under which is a fire to keep it warm; and the reel is of the common construction. However simple the operation, great care and attention are necessary in reeling, to preserve the thread of an equal thickness, and of a round form, and that the several rounds upon the reel should not get glued together. When the skein is quite dry, it is taken off the reel, and being made up into hanks, it forms the article called, in commerce, raw silk, of which such vast quantities are annually imported into this country from Bengal, China, Italy, and Turkey.
In preparing raw silk for dyeing, the thread is slightly twisted, in order to enable it to bear the action of the hot liquor without the fibres separating or furring up. The silk yarn employed by the weavers for the woof or weft of the stuffs which they fabricate, is composed of two or more threads of the raw silk slightly twisted by the aid of.machinery; and the thread employed by the stocking weaver is of the same kind, but composed of a number of .threads corresponding with the strength or quality of the work he is executing.
The first operation it undergoes is winding; that is, drawing it off from the skeins in which it is imported, and winding it upon wooden bobbins, from whence it is taken off for subsequent operations. .In the ordinary method of winding off silk, the reel or swift, upon which the skein is placed, is made to revolve by the pulling of the thread, as it is drawn off and wound upon the bobbin. The great delicacy of the filaments of silk often, however, render this operation difficult, owing to the breaking of the threads; in the winding of Turkish silk, in particular, the process is, from the circumstance just mentioned, extremely tedious, as the thread breaks at almost every turn of the reel; this is owing to the great size of the Turkish skeins, which frequently exceed twenty-four feet in circumference; thus requiring a reel of equal dimensions, that has to be turned round by a single thread; and this thread, being of an uneven thickness, frequently gets entangled in the skein, and unavoidably breaks.
To obviate so great an inconvenience and detriment to the material (by an infinity of knots in the thread), the attention of Mr. H. R. Fanshaw was directed, and by means the most simple and ingenious he accomplished his object in the most happy and perfect manner; this invention, for which he took out a patent in 1827, we shall here describe.
Instead of the reel being turned round by the filament, it remains stationary, but is suspended loosely upon its axis; a light arm or flyer is then made to revolve around the external circumference of the reel, which lifts out the thread from the skein more smoothly and delicately than it could be performed by the finger, conducts it to the centre of motion, and from thence to the bobbin on which it is wound. By this contrivance the thread requires but little more strength than is sufficient to sustain itself, instead of having to drag round a great machine; and it follows that a much finer thread may be wound off by such apparatus than by those of the common construction. Our limits do not permit us to give all the details of this machinery; we shall therefore confine ourselves chiefly to explaining the principal or most important parts, as represented by the annexed diagram. Fig. 1 gives a side elevation, and Fig. 2 a front elevation of a portion of Fig. 1; the same letters in each referring to similar parts, a b is a frame, containing a swift, etc, of which there may be conceived to be a hundred or more in a row, one behind the other, as viewed in Fig. 1, all turned by the same shaft; the diameter of the swift may be considered as eight feet for Turkey silk, but the arms c c are made to elongate or shorten by the slides shown in the middle, so that the swift may be expanded or contracted at pleasure to suit the size of the skein; each of these radiating arms is fixed into a central block or nave d; through this nave a spindle passes, on which the swift loosely rests, as best seen in Fig. 2; e is a pulley, which revolves on the same spindle, and receives its motion by an endless band from another pulley at o.
To the pulley e is affixed the revolving armf, which is furnished at its extremity with a bent wire, coiled up into two spiral eyes; through that at g the filament of silk t t passes as it-is lifted by it out of the skein h; from g it passes through the eye t; from hence it is drawn through another eye i, to the central eye k, (Fig. 2,) and through the last-mentioned on to a bobbin fixed on the same shaft as the pulley o. The situation of the eye k opposite the centre of the axis of the swift, it will be observed, is indispensable to the winding off the thread; it is fixed to the end of a movable rod, which has a joint at l, that permits it at pleasure to be drawn forward beyond the range of the swift, for the girl in attendance to repair the thread, should it be broken. The latter circumstance, however, rarely occurs, by these improved arrangements, and the trembling motion of the bent wire at the extremity of the revolving flyer greatly assists in relieving the silk from entanglement.
The revolving flyer is the principal feature in Mr. Fanshaw's machine, and Is in itself a very beautiful and no less useful invention: there are many subordinate contrivances of great ingenuity, which we have left out of the diagram to prevent confusion.
After silk has been reeled and wound, the next operations are spinning and throwing, which may be performed separately, or at the same time. The art of throwing silk was first introduced into this country in 1719, by Mr. John Lombe, who, with considerable ingenuity, and at the risk of his life, succeeded in taking a plan of a throwing machine in Sardinia, and, on his return, established a mill at Derby for conducting that operation, which had, prior to the above date, been kept a profound secret by the foreign manufacturers. From the great expense incurred in establishing the mill at Derby, application was made to Parliament to extend the term of the patent granted to Mr. Lombe, but the Legislature wisely granted him the sum of 14,000l., in lieu of the extension of the patent right, and upon condition that he deposited in the Tower of London a complete working model of the machine, where it now remains. Since that period many improvements have been successively made, but amongst the most complete and efficient are those introduced by Mr. Fanshaw, and patented by him a short time prior to the winding machinery already described.
To avoid that confusion which would be created by the representation of the vast multiplication of pulleys, wheels, bobbins, flyers, etc, which a throwing-mill embraces, we shall confine our description to the acting parts of a single operation, leaving the reader to imagine an extensive series of them. The engravings on the following page are explanatory of these improved arrangements. Fig. 1 is an end view of the throwing machine; A A is the top of the frame; B the bobbin; C the top spindle; D the board which supports the spindle; E the pulley which gives motion to the set of spindles; F is the flyer to the top spindle; G the lever, which throws the pulley in and out of gear; H the lever pin or centre, on which it works; I the flyer of the bottom spindles J; K is a flutted roller, which propels the drawing roller L, and gives out the thread to be thrown by the spindle C. The silk, after being wound on the bobbins P, is twisted by the revolving spindles J, which are driven by the band M; the-threads g g pass separately through the eyest v, and being united at l, go over the glass rod w, round the roller L, through the eye A, and are then received upon the bobbin B, the twist being effected by the revolving spindle C, which is driven by the band F. Fig. 2 is a bird's-eye view of the machine; the same letters referring to similar parts; R is a tooth-wheel (not shown in Fig. 1) which drives the shaft Q, and gives motion to the rollers K; and at the other end to the bevel gear N, which is connected by a rod to the motion board that draws the bobbin backward and forward, to spread the thread uniformly over its surface.
Fig: 3 is a front view of the machine for making three-thread organzine or sewings, the parts having been already described above, except the bobbins o o, which are shown in dotted lines, and are to be used in case tram is required to be made, instead of organzine. T is a catch to retain the lever G (Fig. 1) in its place when the bobbins are thrown in or out of gear. Fig. 5 represents the end of the bobbin b, which is kept in its place by the small lever w, which lever is fastened on to the motion board s. Fig. 6 is a sectional view of Fig. 5. Fig. 7 is the spindle J, as seen in Figs. 1 and 3, I being a fixed flyer. Fig. 8 is a view of the opposite side of the pulley E, to that shown in Fig. 1. Fig. 9 is an edge view of the pulley E and lever G, as described in Fig. 1.
The advantages of this machine are said to be, 1st, The throwing of organ-zuie by one process, instead of the three separate processes, as at present practised; the spinning by one machine, doubling the threads by another, and throwing by a third. 2dly. In the very great increase of speed which can be obtained. 3dly. In the easy manner in which the machine can be altered to singles, tram, organzine, sewings, or any other description of silk. 4thly. In the saving of labour, from the great quantity of spindles that can be attended to by one hand. 5thly. In the little experience required to enable "a hand" to attend the work, thereby obviating the greatest expense in throwing "mill hands."