Chapter C: D E F are the four printing cylinders, named in the order of their (14)

The manner in which this operates is shown in section in _fig._ 336. Here, we perceive the rod _q_², which extends from the base towards the narrow end of the truncated cone, and _p_² a forked bearer or carrier made fast to the shaft _c´_ by a screw, which compels the cone by means of that rod, to obey the movements of _c´_. In the large end of the cone there is an aperture, through which the bearer can be got at. The smaller end carries outside a projection _o_², provided with a groove, which is embraced by the forked end of a rod _q´_, _fig._ 337., that serves to shove the cone along upon the shaft _c´_. Directly under the cone, there is an upright round pillar _p´_, upon which the holder _o´_ of the two guide pulleys _l´_ is adjustable. A bar _r_² placed along-side of the holder, prevents its turning round, but allows it to slide along _p´_ by friction. The weight of the holder and the pulley is sufficient to distend the endless band _n´_, which runs from the cone _k´_, through under the pulley _l´_, and round the small drum _m´_ on the shaft _s_². A pulley or whorl _t_² with four grooves, is made fast by means of a tube to this shaft, and slides along it backwards and forwards, without ever ceasing to follow its revolutions. The shaft possesses for this purpose a long fork, and the interior of the tube a corresponding tongue or catch. There is besides upon the tube beneath the pulley, at _u_², a groove that goes round it, in which the staple or forked end of an arm like _v_², _fig._ 333., made fast to the copping beam _p_, catches. By the up and down movement of that beam, the pulley _t_² takes along with it the arm that embraces the tube, which therefore rises and falls equally with the bobbins _h´_, and their pulleys or whorls _q_. This is requisite, since the bobbins are made to revolve by the pulleys _t_², by means of 2 endless cords or bands.

The most intricate part of the mechanism is the adjustment, by which the revolution of the bobbins is continually retarded, and their up and down, or copping motion, along the spindles, is also retarded in like proportion. The vertical pulley _f´_, (towards the left end of the shaft _c´_) has at its right side a somewhat larger _disc_ or sheave _g´_, with a perfectly uniform, but not a very smooth surface. Upon this sheave, a smaller horizontal pulley _x´_ rubs, whose upper face is covered with leather to increase the friction. The under end of the shaft _y_² of the pulley _x´_ turns in a step, which is so connected with the arm _v´_ of the large bent lever _t´ v´_, that it always stands horizontally, whatever direction the arms of that lever may assume. The shaft _y_² is steadied at top by an annular holder or bush, which embraces the fast arm _x_² with its forked end. Upon its opposite side, this arm carries a pulley _y_², upon which a cord goes, that is made fast to the holder of the shaft _y_², and loaded with the weight _z´_. The weight presses the pulley _x´_ against the surface of _g´_, in such wise as to effect the degree of friction necessary in order that the revolution of _g´_ may produce an uninterrupted revolution in _x´_. A pinion _w´_, whose length must be equal at least to the semi-diameter of the sheave _g´_, is placed upon the under end of the shaft _y_². It has 22 teeth, and takes into a 62-toothed horizontal wheel _z_². Upon the upper end of this wheel the conical pinion _a_³ is made fast, which may be changed for changing the speed, but usually has from 28 to 30 teeth. By this pinion the conical wheel _b_³ is turned, which has 30 teeth, and whose shaft is _c_³. This shaft carries upon its opposite end a six-leaved pinion, _d_³, which takes into the calender wheel _f_³, formed with cogs like a trundle, upon the long shaft _e_³. In _fig._ 338. the wheel _f_³ is exhibited with its pinion _d_³. Here we may remark that in the circumference of the wheel there is a vacant place, _g_³, void of teeth. When by the motion of the wheel, the pinion comes opposite to this opening, it turns round about the last tooth of the wheel, falls into the inside of the toothed circle marked by the dotted lines, and thus gives now an inverse movement to the wheel _f_³, while itself revolves always in the same direction. This reversed motion continues till the opening _g_³ comes once more opposite to the pinion, when this turns round about the last tooth of that side, and begins again to work in the exterior teeth. Thus, by the uniform motion of _d_³ and its dependent parts, the wheel _f_³, with its shaft _e_³, revolves alternately to the right hand and the left. That this result may ensue, the shaft _c_³ of the pinion must be able to slide endwise, without losing its hold of _a_³ and _b_³. This adjustment is effected by placing the end of the said shaft, nearest _b_³, in a box or holder _i_³, in which it can turn, and which forms a vertical tube to this box, as a downward prolongation which is fixed to the tail of the conical pinion _a_³. _Fig._ 339. shows this construction in section upon an enlarged scale. The second bearer of the shaft nearest _d_³, must possess likewise the means of lateral motion. When therefore the pinion _d_³ shifts through the opening of the wheel _f_³ outwards or inwards, its shaft _c_³, makes a corresponding small angular motion upon the pivot of _a_³, by means of the tube _i_³; _a_³ and _b_³ remain thereby completely in geer with one another.

The above-described alternate revolutions of the wheel _f_³ serve to produce the up and down motions of the bobbins. The shaft _e_³ has for this purpose two pinions _n_² _n_², which work in the rack teeth _m_² _m_² of the copping rail _p_, and thus alternately raise and sink it with the bobbins which rest upon it. The weight of the copping beam and all its dependent parts, is poised by two counterweights _m_⁴, whose cords run over the pulleys _o_⁴ _o_⁴ _o_⁴, _fig._ 332., and have their ends made fast to the frame, so as to make the upwards motion as easy as the downwards. The two upper pulleys out of the three of each weight, are fixed to the frame; the under one, round which the cord first runs, is attached to the copping beam, rising and falling along with it.

As long as the friction disc _x´_ remains at the same height, the pulley _g´_ derives its motion from the same circle of the said disc, and the up and down motion of the copping beam is also uniform. But when that disc ascends so as to describe with its edge a small circle upon the face of _g´_, its motion must become proportionally more slow. This is the method, or principle of retarding the copping motions of the bobbins. It has been shown, however, that the rotation of the bobbins should be also retarded in a progressive manner. This object is effected by means of the cone _k´_, which, as the band _n´_ progressively approaches towards its smaller diameter, drives the pulleys or whorls _q_ of the bobbins with decreasing speed, though itself moves uniformly quick with the shaft _c´_. To effect this variation, the cone is shifted lengthwise along its shaft, while the band running upon it remains continually in the same vertical plane, and is kept distended by the weight of the pulley _o´_. The following mechanism serves to shift the cone, which may be best understood by the aid of the figures 340., 341., and 337. A long cast iron bar _m_³, which bears two horizontal projecting puppets, _o_³ _o_³, is made fast to the front upright face of the copping beam A. Through the above puppets a cylindrical rod _n_³ passes freely, which is left out in _fig._ 337., that the parts lying behind it may be better seen. Upon this rod there is a kind of fork, _p_³ _p_³, to which the alternating rack bars _q_³ are made fast. The teeth of these racks are at unequal distances from each other, and are so arranged, that each tooth of the under side corresponds to the space between two teeth in the upper side. Their number depends upon the number of coils of roving that may be required to fill a bobbin; and consists in the usual machines of from 20 to 22. The rod _n_³ may be shifted in the puppet _o_³, like the fork _p_³ of the rack-rod, upon the rod _n_³, and along the surface of _m_³, where two wings _u_³ _u_³ are placed, to keep the fork in a straight direction. Upon the bar _m_³, there are the pivots or fulcra of two stop catches _w_³ _x_³, of which the uppermost presses merely by its own weight, but the undermost by means of a counterweight _y_³, against the rack, and causes them thus to fall in between the teeth. In _fig._ 341., _v_³ shows the pivot of the catch or detent _w_³ by itself, the detent itself being omitted, to render the construction plainer. A pushing rod _l_³, upon which there is a pin above at _s_³, that passes behind the rack rod, between this and the bar _m_³, has for its object to remove at pleasure the one or the other of the two catches; the upper, when the upper end of the rod pushes against it; the under, by means of the above mentioned pin _s_³. Both the catches are never raised at once, but either the under or the upper holds the rack bar fast, by pressing against one of the teeth. The vertical motion up or down, which the rod _l_³ must take to effect the lifting of the catches, is given to it from the copping beam _p_; since upon it a horizontal arm _v_², _fig._ 341., is fixed, that lays hold of that rod. Upon the pushing rod are two rings, _h_³ and _k_³, each made fast by a screw. When the copping beam is in the act of going up, the arm _v_³ at the end of this movement, pushes against the ring _h_³, raises up the rod _l_³, and thus removes the catch _w_³, _fig._ 337., from the teeth of the rod _q_³, before which it lies flat. At the descent of the copping rail, _v_² meets the ring _k_³, when the motion in this direction is nearly completed, draws down the rod _l_³ a little, by means of the same, and thereby effects the removal of the catch _x_³, _fig._ 337., from the rod _q_³. Every time that one of the catches is lifted, the rack recovers its freedom to advance a little bit in the direction of the arrow; so far, namely, till the other catch lays hold upon the tooth that next meets it. The reason is thus manifest why the teeth of the upper and under sides of the bar _q_³ are not right opposite to each other, but in an alternate position.

From the rack-bar, the sliding of the cone _k´_, and the raising of the shaft _y_², each by minute steps at a time, is produced as follows:--

A large rectangular lever _t_¹, _v_¹, whose centre of motion is at _p_⁴, has at the upper end of its long arm _t_¹, a long slot through which a stud _r_³ upon the rack _q_³ goes (_fig._ 340., 341., 337.,) so that the lever must follow the motions of the rack bar. The end of the short arm of the lever bears, as already mentioned, the step of the shaft _y_²; hence the friction disc _x_¹ will be raised in proportion as the rack bar advances, and will come nearer to the middle point of _g_¹; consequently, its revolution and the shifting of the bobbins will become slower. Upon the cylindrical rod _n_³, the piece _s_¹ _s_¹ furnished with a long slot is made fast, by means of a tube _z_³, (_fig._ 337.) and a screw. A fork _u u_, which by means of the screw nut _a_⁴ is made fast in the slot, embraces the arm _t_¹ of the bent lever; and a tube _r_¹ rivetted to the surface of _s_¹, is destined to take up the draw rod _q_¹ of the cone _k_¹, _fig._ 337. A weight _f_⁴, whose cord _b_⁴ is made fast to the cylindrical rod _n_³, endeavours to draw this rod continually in the direction of the arrow. In consequence of this arrangement, every time that the pushing bar _l_³ lifts up one of the catches, the cone _k_¹, the lever _t_¹ _v_¹, and by it the rack bar _q_³, are set in motion. It is obvious, that the motion of the cone may be made greater or less, according as the fork _u u_ is fixed further up or down in the slot of _s_¹.

The number of the teeth upon the bar _q_³ is so ordered, that the bobbins are quite full when the last tooth has reached the catch and is released by it. The rack bar, being restrained by nothing, immediately slides onwards, in consequence of the traction of the weight _f_⁴ and brings the machine to repose by this very movement, for which purpose the following construction is employed. A rectangular lever which has its centre of motion in _g_⁴ is attached to the side face of the beam A, and has at the end of its horizontal arm a pulley _d_⁴, over which the cord _b_⁴ of the counterweight _f_⁴ is passed. The end of the perpendicular arm is forked and embraces the long and thin rod _k_⁴, to whose opposite end the fork _l_⁴ is made fast. Through this fork the band which puts the machine in motion passes down to the pulley _a_¹. With the bent lever another rod _c_⁴ is connected at _h_⁴, which lies upon the puppet _e_³ with a slot at _e_⁴, and hereby keeps the lever _g_⁴ in its upright position notwithstanding the weight _f_⁴. In the moment when, as above stated, the rack bar _q_³ becomes free, the arm _p_³ of its fork pushes in its rapid advance against the under oblique side of _e_⁴, raises this rod, and thereby sets the lever _g_⁴ free, whose upright arm bends down by the traction of the weight, drives the rod _k_⁴ before it into the ring _i_⁴ fastened to it, and thus by means of the fork _l_⁴ shifts the band upon the loose pulley _b_¹. But the machine may be brought to repose or put out of geer at any time merely by shifting the rod _k_⁴ with the hand.

The operation of the bobbin and fly frame may be fully understood from the preceding description. A few observations remain to be made upon the cone _k_¹, the rack-bar _q_³, and the speed of the work.

When we know the diameter of the empty bobbins, and how many turns they should make in a given time in order to wind-on the sliver delivered by the fluted rollers and the spindles; when we consider the diameters of the spindle pullies _q_, and _t_², as also the drum. _m_¹, _fig._ 332., we may easily find the diameter which the cone must have for producing that number of turns. This is the diameter for the greatest periphery of the base. The diameter of the smaller is obtained in the same way, when the diameter of the bobbins before the last winding-on, as well as the number of turns necessary in a given time, are known.

A bobbin and fly frame of the construction just described delivers from each spindle in a day of twelve hours, from 6 to 8 lbs of roving of the fineness of 1-1/2 English counts. One person can superintend two frames, piece the broken slivers, and replace the full bobbins by empty ones. The loss of cotton wool in this machine consists in the portions carried off from the torn slivers, and must be returned to the lapping machine.

_The fine bobbin and fly frame_ does not differ essentially from the preceding machine. The rovings from the coarse bobbin and fly frame are placed in their bobbins in a frame called the _creel_, behind and above the roller beam, two bobbins being allowed for one fluted portion of the rollers. These rovings are united into one, so as to increase the uniformity of the slivers.

The invention of the beautiful machine above described is due to Messrs. Cocker and Higgins of Manchester, and as lately improved by Henry Houldsworth, junr. Esq., it may be considered the most ingeniously combined apparatus in the whole range of productive industry.

In the fine roving frame the sliver is twisted in the contrary direction to that of the coarse roving frame. For this reason the position of the cone is reversed, so as to present in succession to the band or strap, diameters continually greater, in order that the rotation of the bobbins may be accelerated in proportion as their size is increased, because here the flyer and the bobbin turn in the same direction, and the winding-on is effected by the precession of the bobbin; but if the winding-on took place by its falling behind, as in the coarse bobbin and fly frame, that is, if the flyer turned less quickly than the bobbin, the rotatory speed of the bobbin would be uniformly retarded; in which case the cone would be disposed as in the coarse frame.

When by any means whatever an uniform length of thread is delivered by the rollers in a given time, the bobbin must wind it up as it is given out, and must therefore turn with a speed decreasing with the increase of its diameter by successive layers of thread. Hence proceeds the proposition, that the velocity of the bobbin must be in the inverse ratio of its diameter, as already explained.

With respect to the bobbin and fly frame, the twist is given to the sliver by means of a spindle or flyer which turns in the same direction with the bobbin, but quicker or slower than it, which establishes two predicaments. The first case is where the flyer turns faster than the bobbin. Here the winding-on goes in advance, as in the coarse roving frame, or as in throstle spinning, where the yarn is wound on merely in consequence of the friction of the lower disc or washer of the bobbin upon the copping rail, and of the drag of the yarn. The second case is where the flyer revolves more slowly than the bobbin. Here the winding goes on in arrear, and as the bobbin turns faster, it must receive a peculiar motion, which is uniformly retarded in the ratio of its increase of diameter. This is the case with the fine bobbin and fly frame. When the cone is placed as in _fig._ 332, the winding-on, in either the coarse or fine frame, results from the difference, whether greater or less, between the rotatory speed of the flyer and bobbin.

The motion of the bobbin and spindle is simultaneous, and takes place in the same direction, with a difference varying more or less with the varying diameters of the bobbins. To render the matter still clearer, suppose for a moment the spindle to be motionless, then the bobbin must revolve with such a speed, as to lap-on the roving as fast as the rollers deliver it. The sliver comes forward uniformly; but the bobbin, by its increase of diameter, must revolve with a speed progressively slower. Now, suppose the spindle set a-whirling, it is obvious that the bobbin must add to the movement requisite for winding-on the sliver, that of the spindle in the case of winding-on in arrear, or when it follows the flyers, and subtract its own motion from the twisting motion of the spindles, in the case of winding-on in advance, that is, when the bobbin precedes or turns faster than the flyers; for the diameter of the bobbin being 1-1/2 inch, 10 turns will take up 45 inches. Deducting these 10 turns from the 30 made by the spindle in the same time, there will remain for the effective movement of the bobbin only 20 turns; or when the diameter of the bobbin becomes 3 inches, 5 turns will take up the 45 inches, if the spindle be at rest; but if it makes 30 turns in the time, the effective velocity of the bobbin will be 25 turns, = 30 - 5. Hence in the fine bobbin and fly frame, the number of turns of the spindle, _minus_ the number of turns made by the bobbin in equal times, is in the inverse ratio of the diameter of the bobbin. We thus perceive, that in the coarse frame the bobbin should move faster than the spindle, and that its speed should always diminish; whilst in the fine frame the bobbin should move slower than the spindle, but its speed should always increase. It is easy to conceive, therefore, why the cones are placed in reverse directions in the two machines. Not that this inversion is indispensably necessary; the cone of the fine roving frame might, in fact, be placed like that of the coarse roving frame; but as the torsion of the roving becomes now considerable, and as on that account the bobbin would need to move still faster, which would consume a greater quantity of the moving power, it has been deemed more economical to give its movement an opposite direction.

We mentioned that the twist of the sliver in the fine roving frame was the reverse of that in the coarse; this is a habit of the spinners, for which no good reason has been given.

The divisions of the rack-bar, and the successive diameters of the cone, must be nicely adjusted to each other. The first thing to determine is how much the rack should advance for every layer or range of roving applied to the bobbin, in order that the cone may occupy such a place that the strap which regulates the pulley barrel may be at the proper diameter, and thus fulfil every condition. The extent of this progressive movement of the rack depends upon the greater or less taper of the cone, and the increase which the diameter of the bobbin receives with every traverse, that is, every layer of roving laid on. But care should be taken not to taper the cone too rapidly, especially in the fine roving frame, because in its progress towards the smaller end, the strap would not slide with certainty and ease. We have already shown that the number of effective turns of the bobbin is inversely, as the diameter of the bobbin, or directly, as the successive diameters of the different points of the cone.

H. Houldsworth, jun. Esq. has introduced a capital improvement into the bobbin and fly frame, by his differential or equation-box mechanism, and by his spring fingers, which, by pressing the soft sliver upon the bobbin, cause at least a double quantity to be wound upon its barrel. With the description of his patent equation-box, I shall conclude the description of the bobbin and fly frame.

_Fig._ 342. represents a portion of a fly frame with Mr. Houldsworth’s invention. _a a a_ are the front drawing rollers, turning upon bearings in the top of the machine, and worked by a train of toothed wheels, in the way that drawing rollers are usually actuated.

From the drawing rollers, the filaments of cotton or other material, _b b_, are brought down to, and passed through the arms of the flyers _c c_, mounted on the tops of the spindles _d d_, which spindles also carry the loose bobbins _e e_. In the ordinary mode of constructing such machines, the spindles are turned by cords or bands passing from a rotatory drum round their respective pulleys or whirls _f_, and the loose bobbins _e_, turn with them by the friction of their slight contact to the spindle, as before said; in the improved machine, however, the movements of the spindles and the bobbins are independent and distinct from each other, being actuated from different sources.

The main shaft of the engine _g_, turned by a band and rigger A as usual, communicates motion by a train of wheels _h_, through the shaft _i_, to the drawing rollers at the reverse end of the machine, and causes them to deliver the filaments to be twisted. Upon the main shaft _g_, is mounted a cylindrical hollow box or drum-pulley, whence one cord passes to drive the whirls and spindles _f_ and _d_, and another to drive the bobbins _e_.

This cylindrical box pulley is made in two parts, _k_ and _l_, and slipped upon the axle with a toothed wheel _m_, intervening between them. The box and wheel are shewn detached in _fig._ 343., and partly in section at _fig._ 344. That portion of the box with its pulley marked _l_, is fixed to the shaft _g_; but the other part of the box and its pulley _k_, and the toothed wheel _m_, slide loosely round upon the shaft _g_, and when brought in contact and confined by a fixed collar _n_, as in the machine shewn at _fig._ 342., they constitute two distinct pullies, one being intended to actuate the spindles, and the other the bobbins.

In the web of the wheel _m_, a small bevel pinion _o_, is mounted upon an axle standing at right angles to the shaft _g_, which pinion is intended to take into the two bevel pinions _p_ and _q_, respectively fixed upon bosses, embracing the shaft in the interior of the boxes _k_ and _l_. Now it being remembered that the pinion _q_, and its box _l_, are fixed to the shaft _g_, and turn with it, if the loose wheel _m_ be independently turned upon the shaft, with a different velocity, its pinion _o_, taking into _q_, will be made to revolve upon its axle, and to drive the pinion _p_, and pulley box _k_, in the same direction as the wheel _m_; and this rotatory movement of the box _k_ and wheel _m_, may be faster or slower than the shaft _g_, and box _l_, according to the velocity with which the wheel _m_ is turned.

Having explained the construction of the box pullies _k_ and _l_, which are the peculiar features of novelty claimed under this patent, their office and advantage will be seen by describing the general movements of the machine.

The main shaft _g_, being turned by the band and rigger A, as above said, the train of wheels _h_, connected with it, drives the shaft _i_, which at its reverse end has a pinion (not seen in the figure,) that actuates the whole series of drawing rollers _a_. Upon the shaft _i_ there is a sliding pulley _r_, carrying a band _s_, which passes down to a tension pulley _t_, and is kept distended by a weight. This band _s_, in its descent, comes in contact with the surface of the cone _u_, and causes the cone to revolve by the friction of the band running against it. The pulley _r_ is progressively slidden along the shaft _i_, by means of a rack and weight not shewn, but well understood as common in these kind of machines, and which movement of the pulley is for the purpose of progressively shifting the band _s_ from the smaller to the larger diameter of the cone, in order that the speed of its rotation may gradually diminish as the bobbins fill by the winding-on of the yarns.

At the end of the axle of the cone _u_ a small pinion _v_ is fixed, which takes into the teeth of the loose wheel _m_, and, as the cone turns, drives the wheel _m_ round upon the shaft _g_, with a speed dependent always upon the rapidity of the rotation of the cone. Now the box pulley _l_, being fixed to the main shaft _g_, turns with one uniform speed, and by cords passing from it over guides to the whorls _f_, drives all the spindles and flyers, which twist the yarns with one continued uniform velocity; but the box pulley _k_, being loose upon the shaft, and actuated by the bevel pinions within, as described, is made to revolve by the rotation of the wheel _m_, independent of the shaft, and with a different speed from the pulley box _l_; cords passing from this pulley box _k_, over guides to small pullies under the bobbins, communicate the motion, whatever it may be, of the pulley box _k_, to the bobbins, and cause them to turn, and to take up or wind the yarn with a speed derived from this source, independent of, and different from, the speed of the spindle and flyer which twist the yarn.

It will now be perceived, that these parts being all adjusted to accommodate the taking up movements to the twisting or spinning of any particular quality of yarn intended to be produced, any variations between the velocities of the spinning and taking up, which another quality of yarn may require, can easily be effected, by merely changing the pinion _v_, for one with a different number of teeth, which will cause the wheel _m_, and the pulley box _k_, to drive the bobbins faster or slower, as would be required in winding-on fine or coarse yarn, the speed of the twisting or spinning being the same.

The rovings or spongy cords, of greater or less tenuity, made on the bobbin and fly, or tube roving frame, are either spun immediately into firm cohesive yarn, or receive a further preparation process in the stretching frame, which is, in fact, merely a mule-jenny, without the second draught and second speed, and therefore need not be described at present, as it will be in its place afterwards.

The _finishing machines_ of a cotton mill, which spin the cohesive yarn, are of two classes; 1. the water-twist or throstle, in which the twisting and winding are performed simultaneously upon progressive portions of the roving; and, 2. the mule, in which the thread is drawn out and stretched, with little twist, till a certain length of about 5 feet is extended, then the torsion is completed, and the finished thread is immediately wound upon the spindles into double conical coils called cops.

The water-twist frame, so called by its inventor, Sir R. Arkwright, because it was first driven by water, is now generally superseded by the throstle frame, in which the mechanical spinning fingers, so to speak, are essentially the same, but the mode of communicating the motion of the mill-geering to them is somewhat different. _Fig._ 345. exhibits a vertical section of the throstle. This machine is double, possessing upon each side of its frame, a row of spindles with all their subsidiary parts. The bobbins, filled with rovings from the bobbin and fly, or the tube frame, are set up in the creel _a a_, in two ranges, _b_, _c_, _d_, are the three usual pairs of drawing rollers, through which the yarn is attenuated to the proper degree of fineness, upon the principles already explained. At its escape from the front rollers, every thread runs through a guide eyelet _e_ of wire, which gives it the vertical direction down towards the spindles _f_, _g_. The spindles which perform at once and uninterruptedly the twisting and winding-on of the thread delivered by the rollers, are usually made of steel, and tempered at their lower ends. They stand at _g_ in steps, pass at _v_ through a brass bush or collet which keeps them upright, and revolve with remarkable speed upon their axes. The bobbins _h_, destined to take up the yarn as it is spun, are stuck loosely upon the spindles, and rest independently of the rotation of the spindles upon the copping beam _l_, with a leather washer between. Upon the top of the spindles an iron-wire fork, called a fly or flyer, _i_, _k_, is made fast by a left-hand screw, and has one of its forks turned round at the end into a little ring. The branch of the flyer at _f_ is tubular, to allow the thread to pass through, and to escape by a little hole at its side, in order to reach the eyelet at the end of that fork. From this eyelet _i_, it proceeds directly to the bobbin. By the twirling of the spindle, the twisting of the portion of thread between the front roller _d_, and the nozzle _f_, is effected. The winding-on takes place in the following way:--Since the bobbin has no other connection with the spindle than that of the thread, it would but for it remain entirely motionless, relatively to the spindle. But the bobbin is pulled after it by the thread, so that it must follow the rotation of the spindle and fly. When we consider that the thread is pinched by the front roller _d_, and is thereby kept fully upon the stretch, we perceive that the rotation of the bobbin must be the result. Suppose now the tension to be suspended for an instant, while the rollers _d_, deliver, for example, one inch of yarn. The inertia or weight of the bobbin, and its friction upon the copping beam _l_, by means of the leather washer, will, under this circumstance, cause the bobbin to hang back in a state of rest, till the said inch of yarn be wound on by the whirling of the fly _i_, and the former tension be restored. The delivery of the yarn by the drawing rollers, however, does not take place inch after inch, by starts, but at a certain continuous rate; whence results a continuous retardation or loitering, so to speak, of the bobbins behind the spindles, just to such an amount that the delivered yarn is wound up at the same time during the rotation.

This process in spinning is essentially the same as what occurs in the fine bobbin and fly frame, but is here simplified, as the retardation regulates itself according to the diameter of the bobbin by the drag of the thread. In the fly frame the employment of this tension is impossible, because the roving has too little cohesion to bear the strain; and hence it is necessary to give the bobbins that independent movement of rotation which so complicates this machine.

The up and down motion of the bobbins along the spindles, which is required for the equal distribution of the yarn, and must have the same range as the length of the bobbin barrels, is performed by the following mechanism. Every copping rail _l_, is made fast to a bar _m_, and this, which slides in a vertical groove or slot at the end of the frame, is connected by a rod _n_, with an equal-armed, moveable lever _o_. The rod _p_ carries a weight _r_, suspended from this lever; another rod _q_, connects the great lever _o_ with a smaller one _s_, _t_, upon which a heart-shaped disc or pulley _u_, works from below at _t_. By the rotation of the disc _u_, the arm _t_, being pressed constantly down upon it by the reaction, the weight _r_ must alternately rise and fall; and thus the copping rail _l_ must obviously move with the bobbins _h_ up and down; the bobbins upon one side of the frame rising, as those upon the other sink. Strictly considered, this copping motion should become slower as the winding-on proceeds, as in the fly roving frame; but, on account of the smallness of the finished thread, this construction, which would render the machine complicated, is without inconvenience neglected, with the result merely that the coils of the yarn are successively more sparsely laid on, as the diameter of the bobbin increases.

The movement of the whole machine proceeds from the shaft of a horizontal drum, which drives the spindles by means of the endless bands _x x_. Each spindle is mounted with a small pulley or wharf _w_, at its lower part, and a particular band, which goes round that wharf or whorl, and the drum _y_. The bands are not drawn tense, but hang down in a somewhat slanting direction, being kept distended only by their own weight. Thus every spindle, when its thread breaks, can readily be stopt alone, by applying a slight pressure with the hand or knee, the band meanwhile gliding loosely round the whorl.

The velocities of rotation of the three drawing rollers are, according to this arrangement, in the proportion of 1 : 1-1/2 : 8; and as their diameters are the same, namely, one inch, the elongation of the yarn in spinning is eight-fold. If, for example, the roving was of the number 4-1/2, the yarn would become No. 36. The extension of the thread may be changed by changing the wheels of the drawing rollers. To perceive the power of this change, let us put, for example, in the place of the 18-toothed wheel of the back rollers, a wheel with 16 teeth; we shall find that the elongation will amount, in that case, only to 7-1/2 times, whence the number of the yarn would come out 32 = 7-1/2 × 4-1/2. The extension by the throstle is extremely various; it amounts, in some cases, to only 4 times; at others to 10, 12, or even 15.

The copping motion of the bobbins is produced in consequence of a bevel pinion working in a small bevel wheel upon an upright shaft; while this wheel gives a slow motion by means of a worm screw to the wheel of the heart-shaped pulley _u_, _fig._ 345.

The driving pulley makes about 600 turns in a minute; and as the diameter of the drum _y_, _fig._ 345., is six times the diameter of the spindle wharves _w_, it will give 3600 turns to the spindle in that time. If the pulley be driven faster, for example 700 times in a minute, it will increase the revolutions of the spindles to 4200. The degree of twist which will be thereby imparted to the yarn, depends, with like speed of spindles, upon the rate at which the soft yarn is delivered by the drawing rollers; for the quicker this delivery, the quicker is the winding-on, and the less twist goes into a given length of yarn. If, for example, the front rollers _d_, turn 24 times in a minute, giving out of course 72 inches of yarn in this time, upon which the 3600 revolutions of the spindle are expended, there will be 50 twists to every inch of yarn. By changing the wheel-work of _fig._ 345., or by sticking greater or smaller wharves upon the spindles, the proportion between their velocity and that of the drawing rollers, and thence the degree of twist can be modified at pleasure.

The number of spindles in a throstle frame 12 feet long, is about 60 on each side. The drawing rollers are coupled together as in the bobbin and fly frame, so that each row forms one continuous cylinder. There is a complete roller beam on each side; each of the rollers of the front row is pressed by its top rollers with a weight of ten or twelve pounds; but those of the middle and back rows bear weights of only one pound. In the throstles, there is a guide bar which traverses a small way horizontally to the left and right, in front of the roller beam, to lead the thread along different points of the rollers, and thus prevent the leather of the top ones from being grooved by its constant pressure in one line.

For the service of 240 spindles, in two double frames, one young woman, and an assistant piecer are sufficient. They mend the broken ends, and replace the empty bobbins in the creel with full ones, and the full bobbins of the throstle by empty ones. The average quantity of yarn turned off in a week of 69 hours is about 24 hanks per spindle of 30´s twist. Throstle yarn is of a firm wiry quality, adapted to the warps of fustians and other strong stuffs, as well as to the manufacture of stockings and sewing thread.

There are many modifications of the throstle system besides the one above described; the most celebrated of which are Danforth’s, called the American throstle, Montgomery’s, and Gore’s. I must refer for an account of them to my work entitled “The Cotton Manufacture of Great Britain,” where they are minutely described and illustrated with accurate figures.

_Mule-spinning._--The general principles of the mule have been already stated. This machine is so named because it is the offspring, so to speak, of two older machines, the jenny and the water-frame. A mule is mounted with from 240 to 1000 spindles, and spins of course as many threads.

_Fig._ 346. represents the original _jenny_ of Hargreaves, by which one person was enabled to spin from 16 to 40 threads at once. The soft cords of rovings wound in double conical cops upon skewers were placed in the inclined frame at C; the spindles for first twisting and then winding-on the spun yarn were set upright in steps and bushes at A, being furnished near their lower ends with whorls, and endless cords, which were driven by passing round the long-revolving drum of tin plate E. D is the clasp or clove, having a handle for lifting its upper jaw a little way, in order to allow a few inches of the soft roving to be introduced. The compound clove D being now pushed forward upon its friction wheels to A, was next gradually drawn backward, while the spindles were made to revolve with proper speed by the right hand of the operative turning the flywheel B. Whenever one _stretch_ was thereby spun, the clove frame was slid home towards A; the spindles being simultaneously whirled slowly to take up the yarn, which was laid on in a conical cop by the due depression of the faller wire at A with the spinner’s left hand.

_Fig._ 347. is a diagram of Arkwright’s original _water-frame_ spinning machine, called afterwards the _water-twist frame_. The rovings mounted upon bobbins in the creel A A, have their ends led through between the three sets of twin rollers below B B, thence down through the eyelet hooks upon the end of the flyers of the spindles C, and finally attached to their bobbins. The spindles being driven by the band D D upon their lower part, continuously twist and wind the finished yarn upon the bobbins; constituting the first unremitting automatic machine for spinning which the world ever saw.

Contrast with the above admirable system, the primitive cotton wheel of India, as represented in the annexed figure 348. By the aid of mechanical fingers, one Englishman at his mule can turn off daily more yarn and of far finer quality than 200 of the most diligent spinsters of Hindostan.

_Fig._ 349., is a transverse section of the mule, in which its principal parts are shown.

The machine consists of two main parts; a fixed one corresponding in some measure to the water-frame or throstle, and a moveable one corresponding to the jenny. The first contains in a suitable frame the drawing roller-beam and the chief moving machinery: the second, is called the carriage, in which the remainder of the moving mechanism and the spindles are mounted.

The frame of the fixed part consists of two upright sides, and two or more intermediate parallel bearings, upon which the horizontal roller beam _a_, the basis of the drawing rollers is supported, _b_, _c_, _d_, are the three ranges of fluted iron rollers; _e_, _f_, _g_, are the upper iron rollers covered with leather; _h_, the wooden wiper-rollers covered with flannel, which being occasionally rubbed with chalk, imparts some of it to the pressure rollers beneath, so as to prevent the cotton filaments adhering to them. The rollers are made throughout the whole length of the mule in portions containing six flutings, which are coupled together by squared ends fitted into square holes.

The skewers upon which the bobbins containing the rovings from the bobbin and fly or stretching frame, are set up, are seen at _a_¹, _a_¹, _a_¹, arranged in three rows in the creel _z_. The soft threads unwound from these bobbins, in their way to the drawing rollers, pass first through eyelets in the ends of the wire arms _b_¹, then through the rings or eyes of the guide bar _w_, and enter between the back pair of rollers. The number of these bobbins is equal to the number of spindles in the mule, and twice as great as the number of fluted portions of the rollers; for two threads are assigned to each portion.

The carriage consists of two cast-iron side pieces, and several cast-iron intermediate similar pieces, such as _f_², which all together are made fast to the planks _b_², _c_², _d_². The top is covered in with the plank _k_². The carriage runs by means of its cast-iron grooved wheels, upon the cast-iron railway _l_², which is fixed level on the floor.

The spindles stand upon the carriage in a frame, which consists of two slant rails _x_², _x_², connected by two slender rods _y_², and which frame may be set more or less obliquely. The lower rail carries the brass steps for the points of the spindles _b_³; upon the upper rail brass slips are fixed pierced with holes through which the tops of the spindles play. The spindles are as usual made of steel, perfectly straight, turned truly round, and are all arranged in one plane. To each of them a small wooden or cast-iron whorl _g_² is made fast. They are distributed into groups of 24, and the whorls are arranged at such different heights, that only two of them in each group are upon a level with each other. A small brass head _h_², which every spindle has beneath the upper slant rail of the frame _x_², prevents their sitting down into the step, during their rotation, or sliding off their cop of yarn.

_c_³ are drums, mounted in the carriage in a plane at right angles to the plane in which the spindles are placed. At top they have a double groove for a cord to run in, and the motion which they receive from the great fly wheel, or rim of the mule (not visible in this view) they impart to the spindles. Such a drum is assigned to every 24 spindles; and therefore a mule of 480 spindles contains 20 drums. In the middle of the carriage is seen the horizontal pulley _k_³, furnished with three grooves, which stands in a line with the drums _c_³.

The motion is given to the drums _c_³, upon the right hand half of the carriage by a single endless band or cord which proceeds from the middle groove of the pulley _k_³. The rotation of the spindles is produced by a slender cord, of which there are 12 upon each drum _c_³; because every such cord goes round the drum, and also every two wharves which stand at the same level upon the spindles. It is obvious that the drums, and consequently the spindles, must continue to revolve as long as the main rim of the mule is turned, whether the carriage be at rest or in motion upon its railway.

If we suppose the carriage to be run in to its standing point, or to be pushed home to the spot from which it starts in spinning, its back plank _d_² will strike the post _q_³ upon the fixed frame, and the points of the spindles will be close in front of the roller beam. The rollers now begin to turn and to deliver threads, which receive immediately a portion of their twist from the spindles; the carriage retires from the roller beam with somewhat greater speed than the surface speed of the front rollers, whereby the threads receive a certain degree of stretching, which affects most their thicker and less twisted portions, and thereby contributes greatly to the levelness of the yarn. When the carriage has run out to the end of its course, or has completed a stretch, the fluted rollers suddenly cease to revolve (and sometimes even beforehand, when a second stretch is to be made), but the spindles continue to whirl till the fully extended threads have received the proper seconder after-twist. Then the carriage must be put up, or run back towards the rollers, and the threads must be wound upon the spindles.

This is the order of movements which belong to the mule. It has been shown how the rotation of the spindles is produced.

For winding-on the yarn the carriage has a peculiar apparatus, which we shall now describe. In front of it, through the whole extent to the right hand as well as the left, a slender iron rod, _d_⁵, runs horizontally along, in a line somewhat higher than the middle of the copping portion of the spindles, and is supported by several props, such as _e_⁵. Upon each end of the two rods, _d_⁵, there is an arm, _g_⁵; and betwixt these arms an iron wire, called the copping wire, _f_⁵, is stretched, parallel with the rod _d_⁵. For the support of this wire, there are several slender bent arms _h_⁵ extended from the rod _d_⁵ at several points betwixt the straight arms _g_⁵. The rod _d_⁵ has, besides a wooden handle at the place opposite to where the spinner stands, by which it can be readily grasped. This movement is applied at the left division of the machine, and it is communicated to the right by an apparatus which resembles a crane’s bill. The two arms, _g_⁵, in the middle of the machine, project over the rods _d_⁵, and are connected by hinges with two vertical rods _j_⁵, which hang together downwards in like manner with two arms _i_⁵, proceeding from a horizontal axis _k_⁵.

By means of that apparatus the yarn is wound upon the spindles in the following manner. As long as the stretching and twisting go on, the threads form an obtuse angle with the spindles, and thereby slide continually over their smooth rounded tips during their revolution, without the possibility of coiling upon them. When, however, the spinning process is completed, the spinner seizes the carriage with his left hand and pushes it back towards the roller beam, while with his right hand he turns round the handle of the rim or fly wheel, and consequently the spindles. At the same time, by means of the handle upon the rod _d_⁵, he moves the copping-wire, _f_⁵, so that it presses down all the threads at once, and places them in a direction nearly perpendicular to the spindles; as shown by the dotted line _y_⁵. That this movement of the copping wire, however, may take place without injury to the yarn, it is necessary to turn the rim beforehand a little in the opposite direction, so that the threads may get uncoiled from the upper part of the spindles, and become slack; an operation called in technical language, the _backing off_. The range upon which the threads should be wound, in order to form a conical cop upon the spindle, is hit by depressing the copping wire to various angles, nicely graduated by an experienced eye. This faller wire alone is not, however, sufficient for the purpose of winding-on a seemly cop, as there are always some loose threads which it cannot reach without breaking others.

Another wire called the _counter-faller_, _l_⁵, must be applied under the threads. It may be raised to an elevation limited by the angular piece _p_⁵; and is counterpoised by a very light weight _m_⁵, applied through the bent lever _n_⁵, which turns upon the fulcrum _o_⁵. This wire, which applies but a gentle pressure, gives tension to all the threads, and brings them regularly into the height and range of the faller _f_⁵. This wire must be raised once more, whenever the carriage approaches the roller beam. At this instant a new stretch commences; the rollers begin again to revolve, and the carriage resumes its former course. These motions are performed by the automatic machinery.

There is a little eccentric pulley mechanism for moving the guide beam to and fro with the soft yarns, as they enter between the back rollers. On the right hand end of the back roller shaft, a worm screw is formed which works into the oblique teeth of a pinion attached to the end of the guide beam, in which there is a series of holes for the passage of the threads, two threads being assigned to each fluted roller. In the flat disc of the pinion, an eccentric pin stands up which takes into the jointed lever upon the end of the guide beam, and as it revolves, pushes that beam alternately to the left and the right by a space equal to its eccentricity. This motion is exceedingly slow, since for each revolution of the back roller, the pinion advances only by one tooth out of the 33 which are cut in its circumference.