SILK Manufacture

SILK Manufacture. The processes of silk manufacture fall under two great divisions. The one, comprehending all those operations undergone by the silk in its preparation for textile or other purposes; and the other, those by which the prepared silk is formed into the various beautiful creations of the loom. The operations comprehended in the first division being for the most part peculiar to this manufacture, are those which will here occupy our attention; while those of the second division, being common to the various textile substances, will be found described under the general head WEAVING.

In other textile substances, the manufacturer operates upon bundles of short fibres, which, by drawing out and twisting together, he forms into continuous threads; but in the case of silk, a very different treatment is for the most part required. Here the silk-worm is the spinner, and art is called in, not to join short filaments, but so to strengthen the delicate threads of the worm by combination as to fit them to endure the manipulations to which they are afterwards subjected. We have said for the most part, for this reason, that, from the manner in which the worm labours, there arises a necessity for two modes of operating, one of the nature already described, the other analogous to that of the cotton-spinner; and that the reader may be prepared to understand the reason for this, and many other peculiarities arising from the same cause, we shall here present him with a sketch of the manner in which the worm produces the material to be operated upon; and this sketch needs to be but brief, as in the article SILK-WORM, immediately sequent, the fullest information will be found. When the silk-worm has arrived at that stage of its existence at which it begins to spin, it ceases to feed, grows restless, and moves about, seeking a place wherein to commence its labours. When it has found a corner or hollow fit for its purpose (bunches of dried heather are most properly placed for this purpose), it attaches a long thread from side to side, to form a support for its work; this it does not dispose in any regular manner, but crosses and recrosses it in such a way as to make its work as strong as the situation will admit of. In plying its labours, the little creature by degrees narrows its sphere, and when it has enclosed a space of about the size of a pigeon's egg, its work assumes a more regular cha-

acter, and shortly presents the appearance of a loose silken ball of an oval shape, with the worm labouring inside of it. In a little while, the increasing compactness of the ball renders the labours of the worm no longer evident to the eye, and that it continues to work can only be known by the noise within. When all sound has ceased, the formation of silk has also ceased. Although from the compactness of the ball, the worm labours unseen, we can yet tell by after dissection, and by the unwinding of the thread, that it does not lay its thread regularly round the inside of the ball, but to and fro from one spot to another, for many times, gradually shifting its position, until it has gone over the whole surface, and so gradually, that a great many yards of thread may be unwound without once turning the ball. The thread of the silk-worm is secreted by the animal in the form of a fine yellow transparent substance, and exuded by two minute orifices beneath its jaw; hence the thread is a twin one, formed of two threads proceeding from these orifices, cemented together by a gummy varnish, and when the worm has finished its labour of spinning, it smears over the whole interior surface of its work with the same gum and albumen, doubtless for the purpose of protecting it in its chrysalis state from rain. If we examine the finished work of the worm, we shall find it to consist first of a filament used as that irregularly placed support, and next of a ball of a loose texture and irregularly constructed, serving as an envelope for another ball, compact in its nature, and regular in its formation, within which the worm lies enshrouded. This compact ball is called a cocoon, and its soft envelope floss silk. The thread of the cocoon, from the continuity of its deposition, can be unwound to the end, and the operations to which it is afterwards subjected are those of doubling, twisting, twining, and their accessories, classed under the name of silk throwing. The floss silk, with the additions afterwards to be noticed, is not unwound, but, under the name of waste, has its filaments hackled, combed, and reduced to short lengths, and then carded and spun in a manner analogous to those of cotton.

When the spinning of the cocoons is accomplished, a selection of those that are to be kept for breeding is made, and the remainder are assorted according to their qualities. These are generally reckoned nine, and are as follows:—

1st, Good cocoons; these are strong, firm, and nearly equally round at both ends, not very large, but free from spots.

2d, Calcined cocoons, in which the worm has died, and been reduced to powder by a disease which sometimes attacks them after having completed their work.

3d, Cocalons, larger and less compact than the good cocoons.

4th, Choquettes, cocoons in which the worm had died before it had finished spinning; the silk is fine, but apt to furze in winding.

5th, Dupion, or double cocoons, containing two or more larvae; these are difficult to unwind, and are often kept for seed by ignorant breeders, but the best formed by single worms are selected by experienced growers of silk.

6th, Soufflon, cocoons of so loose and soft a texture as to be almost transparent; these cannot be unwound.

7th, Pointed cocoons. In these one end rises in a point, which breaks off after a little silk has been unwound, and so spoils the thread.

8th, Perforated cocoons, from which the moth has made its way out.

9th, Bad choquettes, in which the silk is spotted, rotten, and blackish in colour.

The first operation to be performed, preparatory to the unwinding of the silk from the cocoon, is to destroy the vitality of the contained worm. The means used for this is heat, either natural or artificial; sometimes simple exposure

to the solar rays will effect this object; but in climates where these have not power, some artificial heat must be employed, such as the heat of steam or of an oven, but more generally that of the latter, though steam-baths are greatly to be preferred. The heat should not be greater than what is used in the oven after the bread has been withdrawn. Long shallow baskets are taken and filled nearly to their tops with cocoons, and are covered over, first with paper, and then with cloth. In these baskets, the cocoons are exposed to the heat of the oven for nearly an hour, and on being withdrawn, several cocoons are chosen from the part of the basket least exposed to the heat, and the chrysalides in them stripped and pricked with a needle. If upon being pricked, they give no sign of animation, it may be fairly presumed that the destruction of the creatures has been accomplished. Before the silk of the cocoons can be reeled off, it is necessary to separate them from the floss in which they are enveloped; this is effected by opening the floss covering at one end, and protruding the cocoon. It is of the greatest importance in the reeling process, that all the cocoons reeled together be of one class.

The apparatus for reeling is sketched in fig. 1, and to avoid confusion, the working parts only are shown: a a is a bath or vessel of water, which, when of the best construction, is heated by steam. Into this the cocoons are put, that the gum which retains the thread in its place may be so much softened as to permit the thread to be unwound; the bath is usually divided by three partitions into four divisions, each of which may contain about five cocoons; b b b are wires with eyelets at their ends, through which the filaments from the cocoons are put. In their upward progress towards the reel, the groups of filaments are twisted round each other, before their final combination at the last eyelet, and by the friction thus produced, they are freed from an adhering portion of the gum; c is the reel driven by a belt from the pulley d, which is itself driven by the prime mover, whatever that may be; f is a tumbler, whose end carries a pulley, which presses on the belt that drives the reel; by lifting up the long end of the tumbler, the belt is slackened, and the reel stops. The filaments when combined at the upper eyelet, pass along the guide e e, and through eyelets at its ends; this guide has a pin projecting from its under side, working in a spiral groove cut round the barrel h; by this it receives a reciprocating motion, and so spreads the filaments equally over the reel.

The filaments, in their passage from the bath to the reel, must necessarily traverse a considerable space, to allow their softened gum to be again hardened by the air, that they may not afterwards adhere together. In China a fire is placed mid-way between the reel and the basin with some advantage.

In the place where the reeling of silk is performed, many of these machines are arranged along the building, and driven by the moving power through a shaft extending the whole length, carrying on it pulleys, at the proper intervals. In working the apparatus, the reeler, who is generally a woman, sits at the bath, and having taken a number of cocoons, immerses them in the water. When their gum is sufficiently softened to permit the thread to come off, the reeler takes a whisk formed of fine twigs bound together, and cut off evenly at the ends at about six inches long, and with it she gently presses and stirs the cocoons, and en-

tangles their loose threads on its points; she then raises her whisk with the thread of each attached to it, disengages them from it, and draws their ends through her fingers, to remove the outside floss or impurity; this process is called battue. Having thus freed the ends of such a number of the filaments as she means to use, she passes them through the various eyelets in the manner previously mentioned, and attaches them to the reel; when this is accomplished, the reel is put in motion by dropping the end of the tumbler, and the filaments are drawn from the cocoons. It is the province of the reeler so to regulate the motion of the reel, and the heat of the water, that the silk may come off the cocoons regularly, not in lumps, which shows that the water is too hot; nor in such a manner as that the cocoon shall be tossed out of the bath, which shows that the silk is yielded with difficulty, from the water being too cold sufficiently to soften the gum.

From the threads of the cocoons being finer near their termination than at their commencement, it becomes necessary for the reeler to add other cocoons before the first set is quite exhausted; and it is her care to do so in such a manner as that the requisite thickness of the compound thread may be kept up throughout. It is generally considered that the filaments of three fresh cocoons added to two half-wound ones, make a thread equal to that from four fresh cocoons.

The cocoons may not entirely wind off, but the husk, or bairré, in which the worm lies, if left, is used along with the floss silk, under the name of waste.

Ordinarily, in China and throughout Europe, 11 or 12 lb. of cocoons yield 1 lb. of reeled silk; and as it takes from 240 to 250 cocoons to weigh 1 lb., the number of cocoons necessary to produce 1 lb. of silk may be reckoned to be 2800; cocoons may yield about 600 yards of silk, consequently the pound of silk filament, as produced by the worm, would, if stretched out, reach the amazing length of 500 to 1000 miles.

When a sufficient quantity of silk is reeled off, it is folded into a hank for use or sale; and it is in this state that it generally comes to be operated upon by our manufacturers,—the hanks by the silk throwster, the waste by the silk spinner.

It is of the utmost importance in the succeeding manufacture, that this reeling process should be well performed. Sometimes from the temperature of the water used to soften the gum being too high during the reeling, the parts of the hank of silk that lie on the spokes of the reel become very hard, and occasion the breaking of the thread in the after processes. Sometimes, too, when in the reeling process the threads happen to break, the ends are again only laid upon one another, and not connected by tying; the threads consequently come off the hanks in short lengths, and much trouble and loss of time is experienced in searching for the other end; and sometimes the reelers, either from inattention or design, reel off the whole of the thread of the cocoons without a regular supply of fresh ones, by which an exceedingly foul silk is produced. Thus coarse and fine silks are reeled together in the same hank; and, what is of common occurrence, the hanks when reeled are twisted up so tight, that the untwisting of them greatly damages the silk. But the greatest injury to the manufacturer arises from dishonesty on the part of those who produce the reeled silk; and this remark applies especially to the coarser descriptions. To get rid of their waste, some producers of raw silk roll up the refuse of the cocoon into what are here technically called dollies, and insert these into the hanks in such a manner that they cannot be discerned by the purchaser; they also have a method of mixing their waste with the good silk while it is being reeled, and as it cannot again be separated from it without great injury, this mode of vitiating the silk is more

Silk Manufacture. objectionable than the other. But dishonest practices are unfortunately not confined to the description of silk above mentioned; it is too common to find in hanks some coarse inferior quality of silk artfully prepared with a covering of a much finer kind, to enhance its value.

The loss of capital, which careless reeling, and the base practices we have alluded to, entail on the manufacturer, is immense; for if an establishment be formed, with machinery and workers sufficient to throw a given quantity of good silk; take, for example, the Italian silk, called Fossombrone, which, of all the raw silks, is the easiest manufactured, and if, in place of some of the Fossombrone, the machines and workers come to be employed on some silks vitiated as we have described, or reeled in a careless manner, then, from the foulness and unevenness of the thread, the number of workers will, in all probability, not be sufficient to attend to above one-third of the machines, one worker being able in a given time to wind five times as much of the Fossombrone as of some of the Bengalee silks.

From what we have said it may be inferred, that it is a matter of great difficulty for the manufacturer to determine the number of machines and workers in the various processes; and that, from the ever varying nature of the silk, he will seldom have the whole of his machinery employed.

If the preparation of the raw silk, as reeled silk is termed, were conducted by persons conversant with the processes of the silk filature, who would adapt their mode of working to suit the various purposes to which the article prepared by them was to be applied; or, if the whole of the operations were under the conduct of an instructed agent of the manufacturers, the evils on which we have animadverted would be removed, and a better and a cheaper article would be furnished to the consumer.

The operations which succeed the reeling are those of silk throwing, and are as follows:

1st, Winding, the silk from the hanks upon bobbins, to fit it for the further processes.

2d, Cleaning, consisting in the silk being unwound from the bobbins of the winding machine, and wound upon another set of bobbins; and, in its passage between, made to pass through an opening between two metal plates, by which any inequality, caused by knots or adhering substances, is removed.

3d, Spinning, consisting in twisting the cleaned thread.

4th, Doubling, consisting in laying together on one bobbin the threads of several bobbins, so that they may be afterwards combined by being twisted together.

5th, Throwing, the name by which the operation of twisting the doubled silk is known, and also the name by which the whole class of operations is distinguished.

It has been conjectured, that the name throwing is derived from the swinging and tossing of the threads and cocoons while reeling, but we need not travel out of the way for its derivation, as the operation of twisting is in many other arts called throwing. The ropemaker throws twist into his ropes; and the little instrument used in the farm-yard for twisting straw ropes, is called a throw-crook.

6th, Reeling, consisting in forming into hanks suited for undergoing the processes of scouring, dyeing, and bleaching the silk which has undergone some or all of the previous operations.

7th, After the scouring, bleaching, or dyeing processes have been performed on the hanks, these have again to be wound on bobbins, for the use of the warper or weaver.

It is not to be understood, that silk in every case undergoes all the operations we have mentioned, but that, when it does so, these succeed each other in the order described.

It is sometimes merely wound and cleaned, and is in this state under the name of dumb singles, used for Bandana handkerchiefs, and, when bleached, for gauze, and similar fabrics.

It may be wound, cleaned, and thrown, and is then called thrown singles, and used for ribbons and common silks. Silk Manufacture.

If wound, cleaned, doubled, and thrown, which twists it into one direction, it is called tram, and is used for the woof or shute of Gros de Naples, velvets, and flowered silks.

If wound, cleaned, spun, doubled, and then thrown, so as to be of the nature of twine, or the strand of a rope, it is called organzine, which, from its strength, is used for warp.

Silk, in any of these states, before being subjected to the operation of scouring, is termed hard, but after it is by scouring deprived of its stiffening-gum, it is called soft.

The operations of the throwster are generally carried on in a building which admits of an apartment being allotted to each description of machines, and these apartments are generally in stories. All the machines used in the processes are each made up of a repetition of the same parts, each part being a distinct and separate apparatus, capable of performing its work independent of its fellows; and these are arranged in juxtaposition in the machine, in order that the moving power may be conveniently applied to a long series of them. The length of the machines is regulated by the extent of the building, and the manner of their arrangement. A manner of arranging them is here sketched (fig. 2.) The apartment is supposed to be about thirty-eight feet wide, and

the machines are placed athwart the room, so as to afford a passage four feet in width along the centre, and at such a distance lengthways, as to give room for the workers to attend to their charge. Two shafts traverse each apartment in the direction of the dotted lines, and carry on them pulleys, or toothed wheels, opposite to each machine; a belt from each pulley is carried over a corresponding pulley on the end of the main shaft of each machine, or the toothed wheels are connected by proper gearing with the shafts of the machines, and so motion is given to the whole.

The rooms are generally heated by steam, and the temperature of the apartments, when above the minimum of 50°, is regulated more by a regard to the health of the workers, than from any necessity for a particular temperature in the operations; but these cannot be performed with advantage when the temperature is allowed to fall below 50°.

The first machine or apparatus used is the winding-machine, or that by which the reeled hanks are wound on bobbins, to prepare them for the subsequent processes. A perspective sketch of this machine is shown in fig. 3. Along

Silk Manufacture. each side of the machine, at a a, directly under the line of bobbins b b, run two shafts, called frame shafts, or frame friction-shafts; on these shafts at each bobbin are fixed two friction pulleys, of about $4\backslash frac\{1\}\{2\}$ inches diameter; and on the axis of each bobbin are fixed two corresponding pulleys, about $1\backslash frac\{1\}\{2\}$ inch diameter. The friction-pulleys of the bobbins rest upon those of the shaft, and receive motion from them. Opposite to each bobbin is a wire, with an eyelet at its end, fixed to a bar of wood c c, called the traverse bar. This bar, with the eyelets attached, has an alternating motion, right and left, through a space equal to the length of that part of a bobbin on which the silk is to be wound. In front of these eyelets are fixed the guide-rods, or friction rods, d d d d, over which the threads glide in their passage from the reel to the bobbins, and which are formed of polished iron, and in front of these the reels e e e e, are placed on their bearers f f. At every seventh bobbin or so is placed a main frame, like g g, and between these stretch bars of wood, for the support of the bobbin and reel bearers. Motion is given to the bobbins, we have said, by the lying shafts bearing friction-pulleys, and the threads being passed from

the reels, over the friction-bars d d, through the eyelets, and attached to the bobbins, are, by the motion of the latter, wound up, and drag round the reel on which the hank is fixed. The bobbins are, with their friction-pulleys, represented in figs. 4, 5, and 6. Fig. 4, a section; fig. 5, a front view, and fig. 6, a plan: a is the lying-shaft, with one of its friction-pulleys b b, and on this rests the friction-pulley c, of one of the bobbins d; the axis of the bobbin is confined laterally by working in the groove e of the bearer, but has perfect freedom of motion up and down, so that its friction-pulley may remain in contact with that of the shaft. If, during the process, a thread happens to break, the bobbin is lifted out of its working-groove and placed in the higher groove f, by which its friction-pulley is kept from touching the friction-pulley of the shaft, and it consequently remains at rest; but when, after the damage has been repaired, it is lifted into its former position, its motion is immediately resumed. In front of the bobbin is seen the traverse bar g, carrying the wire h, with its eyelet for the thread; this traverse bar is moved by an eccentric in such a manner, as not to spread the thread equally over the bobbins, but to heap it up more in the middle than at the ends.

The reels are called swifts, and are formed of twelve light spokes, about $16\backslash frac\{1\}\{2\}$ inches long, inserted into a wooden nave in pairs, so as to form a six-sided reel; the nave has an iron axle, which turns freely on its bearings. The hanks not being all of one size, makes it necessary to have a reel, the diameter of which may be varied. Various means of adapting the reel to the size of the hank have been and still are used. Amongst others, one deserves notice; it is, where each spoke of the reel is made in two parts, the one fixed to the nave, formed of tube containing a spiral spring, the other formed of a light rod, nicely fitting the tube, the opposite pairs of rods being joined together by a cross bar, forming the periphery of the reel. When it is wished to put a hank on a reel of this kind, one of the pairs of spokes is pushed into the

tubes, and the hank slipped on; the spiral springs now exert their force, and throw out the pressed-in spokes with such a force, as to keep the reel in a proper state of tension. But the method generally adopted, if not so elegant, is more simple. The spokes in this case are formed of lance-wood, and the outer extremity of each pair are rather farther asunder than the ends which are inserted into the nave, and are connected together by a band of small cord passed several times round them; on these bands the hank or skein of silk rests, and, by slipping the bands along the spokes nearer to or further from the centre, the diameter of the reel can be adapted to the size of the hank; and when the hank is stretched the bands can be moved in any way, so as to balance the hank, which, as will be afterwards seen, is a matter of considerable importance. Each pair of spokes, it has been mentioned, slightly diverge as they proceed from the nave; and, as they are again slightly drawn towards each other by the bands, the tendency to return to their natural position effectually retains the band in any place to which it may be slipped. It has been said, that the reels turn freely on their supports, but it is necessary to create such a friction as will prevent them giving off the silk faster than it can be taken up by the bobbins; this is sometimes done by a spring being made to press upon the nave of the reel, but more commonly by hanging on its centre a wooden ring, to which weights may be hung, so as to create such a degree of friction on the reel, and, consequently, of tension upon the thread, between the reel and the bobbin, as may be desired. The subjoined sketch (figs. 7 and 8.) shows the

reel as it has been described: a is the nave, b b the lance-wood spokes, c c the bands of cords forming the periphery of the reel, d the friction-ring, with the weight hanging on it.

Referring again to fig. 3, it will be seen, that in front of the swifts are bars of wood, extending along both sides of the machine; their use is to support the bars which carry the swifts, and to prevent the persons of those who work the machines from coming in contact with the reels; from this last use they are termed knee-rails.

Previous to the hanks being put upon the swifts, they are washed in a solution of soap and water, which cleans the silk without depriving it of its gum. In putting the hanks on the reel care is taken to balance them, as were one side heavier than another, it would be apt to fall suddenly, after having passed the highest point, in turning, and thereby injure the thread.

The winding-machines, under the general superintendence of a man called a steward, are tended by girls, who are termed denters and winders; the denters put the hanks on the reel, and the winders, or piecers as they are also called, tie the ends of the threads and exchange the bobbins. When the bobbins are filled with thread they are conveyed from the winding-machine room to the warehouse, to be assorted or separated into finer or coarser qualities, which are kept apart throughout the remaining processes. To carry the bobbins, a board, called a doffing-board, is made use of; this consists of a piece of deal, about a foot wide, and rather more than two feet long, having a number of wires corresponding to the number of bobbins in one side of a frame, and about four inches long, inserted into its surface; on these wires the bobbins are put. When the separation of the qualities has been made,

Silk Manufacture. the bobbins are carried to another machine-room, where the thread undergoes the operation of cleaning.¹

Cleaning. The cleaning, drawing, or picking-machine, as it is variously called, is represented in fig. 9. In this, as in the last machine, motion is communicated to the bobbins by a friction shaft. The bobbins, a a, from the winding-frame are fixed on plain spindles, and placed in a horizontal position between their supports. The threads are carried from the bobbins over the iron or glass rod, b b, and each thread is passed through an adjustable opening, between the two iron blades of an instrument called the cleaner, c c, which is fixed to a bar of wood running along the machine, immediately behind the friction-rods. The cleaner is here represented on a

larger scale, (figs. 10, 11); a is the bar of wood to which the instrument is fastened; b, b, are the blades, which are held together at the bottom by the screw c; d is the opening through which the thread Fig. 10. Fig. 11. is made to pass, the width of this opening being adjusted by means of a screw e, the key of which is kept by the steward of the room. The tops of the blades are curved outwards, so as readily to guide the thread into the slit. The threads, after having been passed through the opening of the cleaner, are put through the eyelet d, of the traverse bar, which is, in every respect, like that of the former machine, and then attached to the bobbins e e. When the machine is put in motion, the bobbins e e drag the thread from the bobbins through the cleaner; and, as the cleaner is adjusted to a certain size, all impurities and irregularities are removed, and the thread thus rendered equal.

Spinning. The process which succeeds that of cleaning is called spinning, although, as we have already observed, it is only twisting. The spinning-machine is represented in fig. 12. This, like the two former machines, consists of a series of frames placed at wide intervals, and connected by bars of wood, which serve as supports for the different parts of the machinery. The spinning machine contains sometimes two but generally three tiers of working apparatus in height. The bobbins on which the twisted silk is to be wound, are seen in the figure at a a a, placed horizontally along the machine; in this case they are not driven by friction-rollers, but by toothed wheels, fixed on the extremity of the axis of each bobbin, and corresponding ones on the shafts b, b, b. The bobbins are, as before, suspended by their axis in little grooves; each bobbin-bearer contains two such grooves, one higher than the other, so that, on the bobbin being

Silk Manufacture. lifted from the lower to the higher groove, its toothed wheel is thrown out of gear with the wheel of the shaft b, b, and it remains at rest. Under each bobbin is seen the twisting-apparatus. This consists of a bobbin c, fixed on an upright spindle d, to which motion is communicated by a belt from the drum f, fixed on a horizontal shaft g, passing over a pulley on the bobbin spindle. The silk threads from these vertical bobbins are wound three or four times round a bent wire h, fixed to a bar, extending along the machine, passed through an eye in the end of each of these wires, carried through the eyes of the traverse-guides, and attached to the horizontal bobbins. On motion being given to the machinery, the vertical bobbins are made to revolve with a greater or less velocity, and the horizontal ones with a velocity so proportioned to the others, that they may only draw away the thread as it is twisted in the due degree. In figs. 13 and 14, we have represented, on a larger scale, a section and front view of these working parts: a, a is the bobbin from the cleaning-machine, b the fixed wire-guide round which the thread is carried, c the traverse-guide for spreading the thread over the bobbin, d the bobbin for receiving the twisted thread.

Fig. 13. Fig. 14.

Motion is communicated to the different parts thus: On one end of the drum-shaft g, (fig. 12.) is fixed a fast and loose pulley, not seen in the drawing, driven by a belt from the main shaft which traverses the apartment; belts from the drum on the drum-shaft pass over the pulleys of the vertical spindles d, and so give motion to the bobbins c; on the hither end of the drum-shaft is fixed the pinion g, which, through the intermediate wheel e, drives the spur-wheel k; on the axis of this last wheel is fixed the bevel-wheel m, giving motion to the

Silk Manufacture. bevel-wheel n, and thereby to the shaft o, which crosses the end of the machine; each end of this shaft carries a bevel-wheel p, which drives a bevel-wheel h, fixed on the end of the shaft, on which the little spur-wheels that drive the spur-wheels of the bobbins are fixed. On this last shaft is also fixed a pinion, to work the traverse guide-bar; this it effects by giving motion to a small wheel, round which another pinion revolves, in the manner of the sun and planet-wheels, and, being connected by a short rod with the traverse-bar, the latter is consequently moved through a space equal to the added diameters of the wheels. In the usual mode of constructing this machine, there is a want of a mean of lessening the velocity of the drawing-bobbin, as its diameter increases by the accumulation of silk. In consequence of this want, the thread is very unequally twisted; for although at the commencement of the process the drawing or upper bobbin may, by appropriate toothed-wheels, be made to turn with the velocity requisite to allow of the thread receiving, say twelve twists in the inch, yet, after a very short time, the silk will have accumulated on it, and increased its diameter so much, that for every revolution which it now makes, it will take up and draw away a much greater length of thread from the revolving bobbin, whose speed remains constant, so that the number of twists are constantly on the decrease, and, at the end of the operation, may be no more than eight in the inch. A very ingenious mode of equalizing the draw of the bobbin has been put in practice. In place of driving the drawing-bobbins by toothed-wheels, they are here driven by friction-rollers; the part of the bobbin on which the silk is wound rests on the roller, and receives motion from it; and, as the diameter of this part increases by the accumulation of silk, its velocity, of course, diminishes in precisely the same ratio; thus, the surface on which the silk is wound has a uniform rate of motion from the beginning to the end of the process, insuring, what has ever been a desideratum, perfect equality in the twist of the thread.

Doubling. The next operation is doubling. Fig. 15 is an end view of the doubling-machine. In this machine the bobbins a a, containing the spun silk, are arranged along the lower platform b, in little brackets capable of each containing three bobbins; from these the threads are carried over the guide-rods d, of which there are two on each side of the machine, and, after being passed through the eyes of an apparatus called the falling-wires, and the traverse-guides e e, are then attached to the bobbins f f, to which motion is given by friction-pulleys, as in the first machines, and on them the threads are thus wound up in combination.

In all formerly described machines the breaking of the thread causes no injury, but, in the doubling process, were one of the three threads to break, and the upper bobbin to continue to revolve, the other two threads would be wound up separately, and so spoil the work; to prevent this is the use of the falling-wires described above, which, on the breaking of the thread, stop the bobbin until the damage is repaired. The subjoined sketch (figs. 16, 17), shows a side view and plan of this apparatus: a a are the two guide-rods, with the threads passing over them;

between the rods are seen the eyelets of three bent wires, whose other extremities are hinged to a piece of brass at c.

The threads are passed through these eyelets, and support the wires in the horizontal position shewn in the sketch. Hinged to the same supports as the wires is a brass lever, bb, bent at right angles horizontally under the wires; the straight end or tail of the lever is a little heavier than the bent end, and it consequently lies in the oblique position of our drawing. On the end of the bobbin is fixed a little ratchet-wheel, moving as indicated by the arrow. Now, when one of the threads sustaining the bent wires happens to break, the wire falls down on the bent part of the lever, which, by this additional weight, is depressed, and its opposite end consequently rises into the position shewn by the dotted line, and acts as a pawl to the ratchet-wheel, effectually stopping the bobbin until the attendant has leisure to lift it out of its working-groove, repair the damaged thread, and again set it in motion.

When the lighter kinds of silk have to be doubled, they would be injured by being made to drag round the heavy bobbins; therefore, for such kinds a modification of the apparatus is required. In place of the bobbins being placed horizontally in bearers, they are placed vertically on spindles, as shewn in figs. 12, 13, 14; the spindles project beyond the upper end of the bobbins, and carry a little wheel of hard wood, which is made to turn freely; this wheel has two flyers with eyelets at their extremities; the thread being put through these, and drawn by the upper bobbins, causes the light flyers to revolve round the vertical bobbin, and unwind the thread without straining it.

The next is the throwing machine. As this machine closely resembles the spinning-machine shewn in fig. 12, we here only sketch such a portion of it as will shew wherein they do not agree. Fig. 18 is an end view, and fig. 19 is a side view of one of the working parts:

aa is a vertical bobbin with its loose flyer bb; the bobbin being driven by a band acting on the spindle pulley as in the spinning-machine; cc is a traverse guide wire, through the eye of which the thread is passed; d a reel on which, in this case, the thread is wound into hanks as it is twisted by the revolution of the vertical bobbins.

The traverse guide bars have, in this machine, a very short range of lateral motion, so as to confine each hank within a very narrow limit on the reel's surface. The motion of the reel can be so regulated in relation to that of the twisting bobbin, as in any way to modify the amount of twisting received by the thread.

In the case of the heavier silk threads used for sewing, fringing, and the like, the doubling and throwing processes are both performed by one machine, called a throstle frame, which is similar to the machine of the same name used in the cotton and linen thread manufacture. The

Silk Manufacture. Manu-throster, however, does not contain apparatus for reeling the silk, so, for this purpose, a subsidiary reel has to be used. This machine is automatic, in respect of stopping when a predetermined quantity of silk has been wound. One end of the axis of the reel is supported by a lever, whose fulcrum is at the centre of the machine; the other end of the axis has a fixed bearing. Motion is given to the reels by a pinion fixed on the end of its axis, being driven by a spur wheel on the main shaft; by raising the lever, which carries one end of the axis, the pinion would be withdrawn from the spur wheel, and the reel would necessarily cease to revolve. The machine is rendered automatic from the raising of the lever being effected by proper machinery at the very instant that the reel shall have wound up the length of silk predetermined, and by a detent locking it out of gear until the attendant shall have time to shift the apparatus which guides the silk to a new space on the reel.

We are sorry that we cannot present our readers with a more minute description of this machine, from the number of drawings which would be required to illustrate it.

Whether the hanks of silk have been reeled in the throwing-machine or on the automatic reel, they are afterwards treated in precisely the same manner. When the reels are filled with hanks, they are placed in a steam box, and subjected for a time to the action of the steam, to give the twisting of the thread a set, as it is termed; each skein or hank is then tied up separately in two places while yet on the reel, which is then carried to the proper apartment, and the hanks removed from it and bundled up.

The silk may be used without being deprived of its gum, and is termed hard, or it may be acted on by soap and water to deprive it of its gum, and reduce it to the soft state. In either of these states it may be put into the hands of the dyer, whose operations succeed those we have described. When the hanks come from the dyer they are again transferred to bobbins; the hard silk by a winding machine, similar to the one already described, the soft silk by the machine represented in fig. 20.¹ In this machine, in place of the swifts are substituted the small

reels A A, the upper one fixed in position but turning freely on its axis, the lower one also turning freely on its axis, which is attached to a lever b, whose short end carries an adjustable weight, by means of which the hank of silk can be kept between the reels with the degree of tension suited to the strength of the thread. The operation of this machine will be understood from the winding machine already described, the only difference being, that the traverse guide has an equal and not an eccentric motion, so as to lay the silk regularly from end to end of the bobbin, and not heaped up in the centre as before. The transferring the silk to the bobbins finishes the operation of the silk throwster, from whose hands the silk passes into those of the warper, to prepare it for weaving.

The drawings of the machinery, by which we have illustrated our description of the throwing process, were, for the most part, made from machines constructed by Mr. Joseph Lomas of Glasgow, an engineer who has devoted much of

his attention to the machinery used in this particular branch of manufacture. Silk Manufacture.

Having thus traced the silk of the cocoons from its development to the perfection of the filature, and its adaptation for the loom, we will briefly describe the means used for preparing the waste silk for the weaver, in so far as they are peculiar to the silk manufacture.

Under this term are included those operations by which floss silk, and the refuse of the throwing process, are, under the name of waste, worked into yarns for coarser uses, such as the manufacture of shawls, Bandana handkerchiefs, and similar textures.

When received by the silk spinner, the waste is in the form of small balls of entangled filaments. These, as a preparatory step, he sorts in parcels according to their quality, and these different qualities are of course kept separate throughout the processes; after being assorted, the waste is hackled on a hand hackle, to disentangle the filaments, the instrument and manner of operating being the same as in flax-dressing. When, by the hackling process, the filaments of a quantity of the waste have, to a certain extent, been disentangled, they are ready for the filling engine, which is a kind of hackling machine, whose effect is, in a greater degree, to disentangle the filaments, and in some measure to lay them parallel.

The essential parts of this machine are sketched in fig. 21: a a is a feeding board, over the surface of which a tra-

velling belt moves in the direction of the arrows, and carries forward to the feeding rollers b b, the hackled waste, which is laid on it. These rollers are fluted and move very slowly; between them the filaments from the feeding board enter, and are held fast, and at the same time drawn forward into the machine. As the ends of the filaments come to the other side of the rollers, they are acted upon by a series of iron teeth c c, fixed to an endless belt which revolves with a very quick motion in the direction of the arrows, and the teeth are consequently made to pass many times through the same portion of the filaments, clearing and disentangling them as they are slowly yielded by the feeding rollers; and as the ends of the successive portions of filaments cease to be held by the rollers, they are caught up by the teeth and carried round with them. Beneath the combs, as the travelling teeth are termed, a board d is fixed, having at intervals, along its surface, sets of teeth similar to the combs. When the filaments carried round by the travelling combs happen to fall off, they are caught on the fixed combs of the boards, and the regularity of their arrangement is not disturbed. When the combs, by repeated gleanings from the rollers, have become filled, the workman, with a pair of boards called clutches, removes from them, and from the teeth of the horizontal boards, their accumulation of filaments; these he carries to the next machine, called the dressing frame, which, like the filling engine, operates on the principle of combing. In this, however, the filaments are not gradually brought for-

Silk Manu- ward by rollers and yielded to the comb, but they are held
factory. firmly in their place by one end, while the combs travel
over their surface, dragging away all impurities and all fibres
which are shorter than the average length of the mass. Fig.
22 is a side view of the machine: $aa$ is a fixed framing, at

each end of the frame is a roller $bb$; over these rollers the
endless web $cc$ moves. Motion is communicated to the
roller $b\text{'}$ by the spur wheel $d$, on its axle being driven by a
pinion on the axle of the pulley $e$, to which motion is given
by a belt from a pulley of the main power shaft. The distance
between the rollers $bb\text{'}$ can be increased or diminished by a
screw connected with $b$, so as to tighten or relax the end-
less web which travels round them. The endless web car-
ries the combs $ff$, which, in this machine, are composed of
a great number of short inclined teeth. Immediately be-
low the top bar of the machine is seen the side of an iron
frame $gg$, in which the silk to be operated on is fastened.
Along the frame is seen the ends of a series of boards, whose
lower edges are hinged together; between these boards,
when opened like a book, the ends of the silk filaments from
the filling engine are inserted, and the boards closed and put
into their place in the iron frame, and between every pair
of these boards is put a piece of solid wood. The pinch-
ing screws $hh$, at the ends of the iron frames, are now turn-
ed, and the silk is thus held tightly between the boards.
The iron frame, it will be seen, rests upon two supports $jj$,
which, by means of a rack and pinion worked by the wheel
$k$, can be moved up or down, and thus the frame can be
raised or lowered; when lowered to its utmost extent it
rests on the wheeled carriage $l$, which runs on the floor on
a railroad placed at right angles to the machine. The
operation of the machine is as follows: The frame which
contains the silk is lowered until it rests on the carriage,
which is then drawn out at the side of the machine. The
boards containing the silk are then put into their places
and firmly compressed by the pinching screws; the car-
riage is now returned to its place under the combs, and
by means of the wheel, the frame is adjusted so that the
combs may act on the silk. The machine is then put in
motion, and the combs, by repeatedly passing over the
silk, disentangle and lay parallel the filaments and re-
move impurities. When the combing of one side of the
filaments has been effected, the frame is again lowered, and
the carriage withdrawn. The workman with a skewer turns
over the silk so as to expose the uncombed side, wheels
round the frame on its centre pivot $m$, and again runs the
carriage into its place; again he raises the frame until within
the scope of the combs, which constantly move in the same
direction; and thus both sides of the material come to be
thoroughly operated upon. The gleanings of the silk ga-
thered by the combs, when accumulated, are screwed be-
tween the boards, and again subjected to the action of the
machine; what is carried away by the combs in this opera-
tion is unfit for spinning, and is used, like the refuse of flax,
for stuffing cushions and similar purposes.

When the filaments are by the dressing machine cleaned
and laid parallel to each other, they are cut into lengths of
about an inch and a quarter by the cutting engine, which
operates upon the principle of chopping, and resembles the
agricultural chaff machine. It is then operated upon by

the scutcher, which is a modification of a similar machine Silk-worm
used in the cotton manufacture. When it leaves the scut-
cher it resembles fine down, and is put into bags of a con-
venient size, and boiled for an hour and a half or so in soap
and water, to deprive it of its gum; it is afterwards washed
in pure soft water and again boiled, but not now for so long
a period, this boiling being merely for the purpose of get-
ting rid of impurities. It is then subjected to the action of
a Bramah press, and when taken from the press, dried by
means of a stove, after which it is cooled, and a second
time passed through the scutching machine to fit it for card-
ing. The carding is followed, as in the cotton manufacture,
by the drawing and fly frames, to produce a rove, and these,
by the spinning mill and the throstle, after which reeling
and bundling complete the operations and fit the thread for
the market.

The art of silk-waste-spinning, we may observe, is still
in its infancy, but is advancing rapidly to greater maturity.
In 1814, the quantity of waste imported by Great Britain
amounted to 28,996 lb., and in 1836 it had reached to the
amount of 1,509,334 lb. In the years 1856, 1857, 1858,
it averaged 2,069,684 lb.