(66) After the cotton has been opened by any of the machines just described it is passed into a machine commonly known as a “scutcher.” In this it is subjected to a further beating action, which in this case, however, has the object of cleansing rather than opening it. Machines of this class may be either single or double, that is, the cotton may in passing through the machine be subjected to the action of one or two beaters. Occasionally, but very rarely now, three beaters are used. It is becoming a more general practice to use an opener and single beater combined as a first stage and a single beater machine as a second stage, but there is no fixed rule in this respect, the actual facts of each case determining the procedure. At one time the opened cotton was ejected in a loose condition from the opener, and was placed upon the scutching machine feed-table by hand, often being weighed. As an English practice this is becoming obsolete, the system of pneumatic suction being employed to convey the cotton from one machine to another. Openers have very often attached to them a lap machine, which forms the cotton into a roll or “lap.” As the “lap” attachment is one which is common to most cleaning machines a description may be given of it at this point.

(67) This attachment consists of two fluted rollers (L L Fig. 22), which are suitably revolved, and on which the roll of cotton M is formed, being lapped round a rod or tube by the frictional contact of its surface with the rollers L. Before it reaches this point the cotton is formed into a sheet on the dust cages, as described in the preceding chapter. The iron rod or tube is made long enough to act as an axis for the lap to revolve on, and to enable it to be carried about from place to place for further treatment by succeeding machines. As the sheet or fleece leaves the dust cages J it is passed between a pair of smoothly turned rollers, the upper one of which is weighted so as to calender or compress the lap. This is a matter of some importance, as it renders the surface of the lap smoother and prevents the various layers adhering to each other when unrolled. An arrangement is fitted by which the attainment of a defined diameter of lap releases the setting on handle, causing the latter to move and transfer the strap on to the loose pulley stopping the machine. The importance of forming laps is now well recognised, and will be dealt with at greater length at the end of this chapter.

(68) Fig. 22 represents a side elevation of a single scutching machine, as made by Messrs. Lord Brothers, that is, one which beats the cotton once. It contains a revolving beater A, fixed upon a central shaft and driven at a high velocity from a counter shaft. The beater consists of arms, forged solid, with a central boss, and having feet at their outer ends. The arms are keyed firmly on the shaft, and may be either round or elliptical in shape. There are either two or three arms on each boss, and a number of them are secured to the shaft along its length within the beater case. According to its construction the beater is known as a two or three “winged” beater. However made, it is carefully shaped and machined, so as to be in perfect balance, and this is a most important point in the construction of the machine. Too much stress cannot be laid on the necessity for extreme care in this matter. Not only should the beater arms be balanced prior to fixing, but after having been keyed on the shaft the same operation should be carried out. In order to balance the beaters thoroughly it is better to revolve them rapidly, while sustained in bearings having freedom of sliding movement in a frame. The velocity at which they are tested should be considerably in excess of that at which they work, and no pains ought to be spared to get the beater in absolutely true balance when working. Otherwise the vibration set up would be considerable, and the character of the blow given would be intermittent instead of regular. Before the final balance is given the blades should be attached to the arms. The blades are made of steel—or of a combination of steel and iron fused together—of an irregular section, angularly formed at one side, so as to present a moderately sharp face to the cotton as it strikes it. The blade requires to be made with a slight clearance, so as not to rub the cotton after striking it.

(69) The question as to which is the better form of beater to use—a two or three-winged—is one which is difficult to answer. Most makers to-day are using the former, while others—as for instance, Messrs. Platt, Brothers and Co.—while employing a two-winged beater for the “breaker,” use a three-winged for the “finisher” scutching machine. From the constructor’s point of view the two-winged beater has undoubted advantages, as it is at once more easily made, and balanced with much less difficulty. The diameter of a two-winged beater is usually 14 inches across the blades, and of a three-winged 16 to 18 inches. The velocity of the former is greater than that of the latter, being in one case 1,200 to 1,500 revolutions per minute, and in the other 900 to 1,000. Thus the peripheral velocity of the two-winged beater is from 4,314 to 5,497 feet per minute, and that of a three-winged, 4,100 to 4,700 feet per minute. Although a three-winged beater, running at 1,000 revolutions, will strike the cotton 3,000 times per minute, the two-winged form, running at the higher velocity of 1,500 revolutions, will give the same number of blows. There is, however, the character of the blow to be considered. The smaller diameter in the case of the two-winged enables the higher velocity to be reached, and the blow given is sharp and quick. In addition to this, the smaller circle described by this form of beater causes the blade, after having struck the cotton, to leave it rapidly; whereas the larger diameter of the three-winged one leads to the blade being longer in contact with the cotton than it otherwise would be. This, coupled to the comparative slowness of its peripheral velocity, gives a dragging blow, which is not a good thing for the cotton, as it is apt to crush or bruise the fibres. The longer the staple the slower the velocity of the beater should be, and this has an important bearing on the subject. For instance, with good cotton, the velocity of a two-winged beater is sometimes reduced to as low as 1,000 revolutions, while with Indian cotton the higher velocity is preferable. These considerations tend to show that the two-winged beater is the most suitable.

(70) There is another point which, however, deserves a word or two. The regularity of the pulsations of a scutcher beater is a matter requiring consideration. It is a subject not always thought of, but it has a great influence upon the resultant lap. The cotton—as will be hereafter shown—is struck from a roller or pedal, and is thrust into the range of action of the beater blades at a defined and regular rate. As it is desirable to beat it into small tufts before flinging it on to the grids, and as the cotton is liable to damage if the pieces struck off are too large, it follows that the oftener the blades strike the better. That is, of course, assuming they do not strike so often as to powder or crush the fibre. Now, there is no reason in this consideration, for the employment of a three-bladed beater, which does not strike the cotton more frequently than is the case with one with two blades.

(71) It is usual to form laps at the termination of each scutching process. These are first made, in most cases, on the opener, or failing that, on the breaker scutcher. The laps thus made are fed to a second machine called the finisher scutcher, where a new lap is made, which is fed to the carding engine. It is therefore desirable to obtain the utmost regularity in the last lap named, and for this reason the pulsations of the beater become important. On this account Messrs. Platt Bros. and Company use a three-winged beater in their finisher scutcher, believing that the result is more satisfactory.

(72) Surrounding the beater at its upper portion is a case, made quite air-tight. Beneath the beater a grid H is placed, the bars of which are set to present a sharp edge to the cotton. The number of these varies according to the class of cotton used. Careful regard should be given to this factor. In fixing the bars they should be placed as shown in Fig. 24. The front bars C should have their cleaning edges set a little in advance of a perpendicular line drawn across an imaginary line horizontal to the axis. The angularity thus given should decrease as the bars are further from the feed roller. The reason of this is obvious. As the cotton is struck from the feed rollers it is desirable that it should receive a sharp check at once, in order to shake out the freshly-freed impurities. This requirement becomes less urgent as the cotton passes onward and the arrestment of its traverse is less necessary.

(73) The circle described by the top of the bars should not be concentric with that of the beater blades, but ought to be as shown in Fig. 24, further from the centre of the beater shaft at the back than it is at the front of the grid. The reason for this is that the bulk of the cotton after being scutched becomes greater, owing to its more open condition, and it naturally requires more room, to avoid any choking or entanglement. Further, if the grid is comparatively long the distance between the bars—in other words, their pitch—must be increased. Below the bars is a chamber into which the dirt can fall freely, and which is closed by doors from without. The pitch of the bars should be large enough to permit of the easy passage of the dirt.

(74) Messrs. Howard and Bullough use, in addition to the fixed bars shown, the additional bars D, which are pivoted at their lower end, as shown, in a movable plate. This plate is attached to a lever E, which can be operated from the outside. The purpose of these bars is to admit of the admission of more or less air as desired. The space below the fixed bars and that below the air bars are separated by a thin division plate F. It is claimed for this arrangement that the fall of the dirt through the bars C is considerably facilitated.

(75) After passing the dirt grids, the cotton falls on to a second grid, or plate, as preferred, and then between a short “dead” plate and “beater sheet” to the cage J on to which it is drawn. The cage J consists of a skeleton cylinder revolving on a shaft, and having its periphery formed of finely-perforated sheet metal. Each end of the cage terminates in an air passage or trunk extending upward as shown. At the foot of the trunk the fan I is placed, which exhausts the air through the cages, and sucks the cotton on to them so as to form a continuous sheet or fleece. From the cages the fleece is taken to the lap attachment, which has been previously described.

(76) Messrs. Crighton and Sons, a perspective view of whose machine is given in Fig. 25, make their cages in a somewhat different manner to that just described. The ends of the cages are fitted into the framing, which is recessed at each side to receive them. Their peripheries are formed of woven wire webbing, instead of the perforated zinc sheets mostly used. At the end of the cage the webbing is protected by a brass ring, which keeps it firmly in position. The effect of this arrangement is two-fold. A greater space is left for the passage of the air than is possible with a perforated metal covering, and as a result, the intensity of the current is reduced. In addition to this, the fleece of cotton is laid on the whole of the face of the cages, because the manner in which they are fitted into the framing practically causes the latter to act as a guide, beyond which the cotton cannot spread. In this way the edge, or “selvedge,” of the lap is rendered very even, a subject the importance of which is further dealt with in paragraph 99.

(77) Another point of special construction, adopted by the same firm, is the position of the “dead plate.” This is the name given to a plate below which the scutched cotton travels, extending across the machine immediately behind the beater. As the cotton leaves the range of the beater, it falls upon a plate or sheet called the “beater sheet,” immediately below the “dead plate.” Now, for reasons to be given, the position of this plate is important, and in the machine as made by Messrs. Crighton, its distance from the beater sheet is 2¹/₂ inches. Immediately beyond this point the same firm use an appliance known as a “leaf extractor,” of which an illustration is given in Fig. 26. It consists of an endless brattice or canvas band D, as wide as the space between the frames, and having fastened to it transverse bars of wood B. These are shaped as shown, with an edge meeting the cotton as it moves forward, thus scraping off the leaf, and the space contained between each pair of these practically forms an air-tight box for the reception of the leaf. The brattice moves in the direction of the arrow, and thus meets the cotton as it passes from the beater. It is kept in tension by means of the rollers E F and G, and as the bars pass over E, which is unattached, its weight causes them to open, and so drop the leaf into the chamber below. Having thus described the mechanism of this special arrangement, it is necessary to say something of the draught regulation and the effect it has upon the work.

(78) The regulation of the air current is one of the most important features in the working of a scutcher. Other things being equal, it is not too much to say that success or failure largely depends upon it. On the one hand, it is necessary to provide sufficient suction to draw the cotton forward and lay it evenly on the cages; on the other, an excess of suction is very detrimental, as, if the movement of the cotton is too rapid it will be drawn over the dirt grids before instead of after the dirt and leaf has fallen. More especially for the sake of the removal of leaf does the current require to be slow. With any other procedure the lighter matter cannot fall, and is carried forward to the cages. An excess of suction further results in the cotton fibres being drawn into the interstices of the cage surface, and the fleece does not in that case leave the latter easily. This results in a rough surface of the lap, and leads when it is rolled up to “licking,” or adhesion of the different layers.

(79) It is therefore desirable to get the draught as nearly balanced as is consistent with the required onward movement of the cotton. What is wanted is rather a large volume of air moving at a slow pace than a smaller one travelling more quickly. The fan should therefore be as large as can be conveniently arranged, and should be run at a comparatively slow velocity. Its exit orifice must be of ample size, and no obstruction be presented to the current of air. The latter is delivered into a passage or conduit running below the floor and terminating either in the open air or a specially-arranged chimney. All these passages must be made of ample size, and cases are numerous in which neglect of this requirement has resulted in the inefficient working of a machine which otherwise ought to have worked well. The atmospheric changes render it necessary to watch the regulation of the current so as to suit them, within limits.

(80) The precise effect of the arrangement of the dead-plate and beater-sheet referred to in paragraph 77 is to decrease the work thrown upon the fans. The beater, by reason of its rapid rotation, creates a sufficient current to carry the cotton on to the grids or extractor, if the space between the dead-plate and sheet is narrowed as described. If that be increased the effect of the impulse thus given is diminished proportionately. When so arranged, the cotton impelled as described passes gently over the leaf extractor, being aided by the slow current created by the fans, and thus allows the leaf to fall freely and without difficulty.

(81) In Fig. 27 a diagrammatic representation of Messrs. Platt Brothers and Company’s arrangement is given. In this case, also, the dead-plate is arranged so as to narrow the exit orifice from the beater, with a similar beneficial effect to that described. The cotton then passes over the bars of a dirt box L, into which the leaf can fall, being periodically removed.

(82) The feed apparatus used is now almost universally combined with a regulator which bears the name of its inventor, the late Mr. E. Lord, of Todmorden, and is commonly known as the “piano feed.” It is one of the most effective motions in the whole range of textile mechanics, and has considerably increased the regular working of this particular machine. Referring now to Figs. 28 to 31, which are respectively side, end, and plan views, it will be seen that the cotton is fed from the lattice H over the nose of the pedal lever A and under the feed roller B. After this it is struck by the beater G in its rotation. The shape of the pedal nose varies considerably, according to the length of the cotton used, the modification in Fig. 28 being that used for short, and the one in Fig. 29 being employed for long stapled cotton. The pedal lever is hinged upon a rod, and has behind its fulcrum a long tail piece which terminates in a hook I. On to this a pendant lever C is suspended. The lower portion of each of these pendants is widened so as to form a double taper surface, as shown in the end view at D. Between each pair of pendants, at its lower end, small runners or bowls are placed, these being fixed in rods sliding in the double frame F, which at the end E is tied together. The last of the series of pendants C¹ is formed with a slot, as shown, with which a lever is jointed, as will afterwards be described, and as is further shown in Fig. 23, which is an end view of the machine shown in Fig. 22. All the pendants can swing freely upon the pedal levers. The latter are placed, as shown in the plan, in close proximity to each other, so as to cover the whole space below the feed roller, while at the same time they have freedom of movement.

(83) Referring now more particularly to Figs. 22 and 23, the last pendant lever is coupled by the connecting rod O and the levers shown to the two strap levers E, which have sectors formed at one end gearing with each other. These levers carry the guides for the strap N, which is tightly placed upon the cones D D¹. These are respectively convex and concave, their outline being a parabola. The cone D¹ is driven by means of the strap shown from a pulley on a counter shaft, and revolves at a velocity of 600 revolutions. The other cone D is driven from D¹ by the strap N, and is fixed upon a spindle or shaft which is carried upward (Fig. 23). On the upper end of the shaft is a worm P engaging with a worm wheel R on the feed roller, which is driven by these means, or a change wheel may be interposed if desired.

(84) The action of this mechanism is as follows. As the cotton is delivered by the lattice it passes over the nose of the pedal and between it and the feed roller. If there happens to be a thick piece in the feed it depresses the nose of the pedal over which it passes. This raises the pendant rod C. Now the space between the thinnest portion of the pendant foot and the bowls is only sufficient to enable the pendant to rise a little before pressing on the bowl next it. Its motion being limited in this way, and the tendency to rise still occurring, either the pendant must become jammed or the bowl must have liberty to move to one side. This is what occurs, the lateral movement of the bowl being permissible to the extent which corresponds to the space between the remaining pedals and their adjoining bowls. After this is taken up, pressure exercised by the rising pendant upon the bowl causes the bar in which the latter is fixed to move in the box to an extent which is regulated by the depression of the pedal nose. In other words, the pendant swings on the end of the pedal lever either to the right or the left as may be required, giving a similar movement to the rest of the series. The movement thus set up is communicated to the strap levers E by means of the connecting rod O and its attachments, and the strap is accordingly raised or lowered as required by the circumstances of the case. The weight of the parts connected to the pedal levers are sufficient to press their noses against the feed roller unless prevented by means of the cotton being fed. Thus a thin place in the material at any part of the width of the feed roller is followed by the reverse action to that named, the strap being moved on the cones in a similar manner. The presence of a thick place in the feed decreases the velocity of the driven cone and feed roller, while the reverse action occurs when a thin place is presented. Thus the retardation of the cotton in the one case leads to any extra thickness being rapidly beaten out, more blows being given to the same length fed than would be under ordinary circumstances. On the other hand, a thin place results in the quickening of the feed roller and a greater quantity of cotton is beaten off in the same time. In this way an evenly-weighted delivery takes place, and this, in conjunction with the lap feed, of which more will be said hereafter, enables a lap to be finally produced, in which the variations of thickness are comparatively slight.

(85) At one time it was the universal custom to strike the cotton directly from the pedal nose Fig. 32, a practice which, however the latter was shaped, had many defects. A much better method is adopted by Messrs. Platt Brothers and Company, and is shown in Fig. 33, which illustrates the new practice. It will be seen that, when the beater strikes the cotton directly from the pedal nose, the fibres will be bent sharply round an angle. In the case of long-stapled cottons especially this is detrimental, as it is liable to lead to rupture or breakage of the fibre. With the shorter-stapled varieties this is not so likely to occur, and the use of a pedal and feed-roller is more permissible. The arrangement shown in Fig. 33 is a much better one, and consists in the employment of an additional pair of feed rollers placed between the pedal and the path of the beater. There are two distinct advantages from this procedure. The cotton is bent round a larger curve when it is struck by the beater, and is, therefore, less liable to rupture; and the feed-rollers exercise a certain amount of drawing action. The latter point is of some value. The cotton in passing under the feed roller and between it and the pedal nose is held by them. The correction of thick or thin places and the alteration of the speed of the feed to meet them is controlled from this point. If the second set of rollers revolves at a slightly quicker speed than the one above the pedal the cotton will be a little drawn. In any case, this action will take place to a greater or less extent, and the thick places will thus be partially thinned out before being struck by the beater. The shock of the stroke is thus considerably diminished, and the risk of damage much lessened.

(86) It only remains to be said with regard to the Lord pedal motion shown in Figs. 28 to 31 that it is now amended by the introduction of two bowls between each pair of pendants, which are acted upon singly by the pendant they adjoin. The latter point is illustrated in Fig. 34, which represents the old method of arranging the pendants and rollers, and an improved plan of Messrs. Howard and Bullough. In the former case each pendant engaged with one side of a bowl, with the other side of which the adjoining pendant also engaged. In the event of both of the latter rising at once, it is apparent that the bowl will tend to be rotated in opposite directions. In effect it becomes practically inoperative, and the friction set up is considerable, preventing the easy movement of either pendant. To obviate this, the three-bowl arrangement shown in Fig. 34 is adopted. The pendants are made with one flat face, and with one on which a rib is formed. On the spindle three bowls are placed, the centre one being of smaller diameter than the others. The two outer bowls engage with the flat side of one of the pendants, but are entirely out of contact with the adjoining one. On the other hand, the central bowl engages with the rib formed on one pendant, but is too small in diameter to engage with the flat face of the next of the series. Thus the whole of the pendants could rise simultaneously without setting up the friction referred to owing to the cross torsion on the rollers. The sensitiveness of the motion is thus largely increased. The adoption of two bowls, each independent of and out of contact with the other, produces a similar result.

(87) There are several modifications of the pedal motion in use, but, before passing on, the arrangements used by Messrs. Platt Brothers and Company may be described. Dealing first with the driving of the cones reference may be made to Fig. 35. The spindle of the driving cone B is prolonged so as to rest in a footstep and has fixed upon it the double-grooved pulley S. An endless rope or band is passed round the pulley I, which is the driving pulley, and thence passes round the pulley G, carried on a pin, the position of which can be regulated by the screw shown. After going once over the pulley G the band is conveyed round the upper groove of the pulley S, back to G, thence to the carrier pulley shown, again round S, and finally returns to the driving pulley I. A little consideration of the course thus followed will show that there is a pull upon the spindle of the cone B in diametrically opposite directions, and as the pull is in each case equal, the wear of the shaft and footstep is materially reduced. The consequence is that high velocities can be attained with the utmost ease, and without any undue strain upon the ropes or shafts.

(88) Referring now to Fig. 36, which is a front view of the pedal arrangement, it will be noticed that the levers P are each of them placed between two bowls, which are actuated by their own pendants only. Instead of coupling the regulating levers to the last of the series of pendants, a different arrangement is adopted. The hanging lever O is fastened at its upper end on a pin carried by the horn bracket shown, which is fixed to the bowl box. On the other end of the pin is a second lever, shorter than O, and also fixed to the pin. Thus any oscillation of the lever O is followed by a similar movement of the second lever. The lever O is long enough to enter the bowl box, and any lateral movement of the bowls causes a similar movement in the lever. This is repeated by the shorter lever, which is coupled to a connecting rod Q. The latter is made in two parts, connected by a nut, with a right and left handed thread, so as to permit of any adjustment necessary, which is also aided by the slots shown as existing in the various levers in the series. The rod Q is jointed to an L lever R, on the horizontal limb of which the balance weight T is fastened by means of a pin passing through the slot. To the extremity of this limb of the lever R a chain F is coupled, which, passing over a grooved pulley placed above the cone box, is attached to each of the strap levers O P (Fig. 35). These levers are hinged in the manner shown, and carry strap forks acting upon the strap C. The relative positions of the strap and levers, at a point midway of the length of the cones, are shown by the dotted lines in Fig. 35. On the spindle of the cone A is the worm L, by which the feed rollers are driven, the three roller arrangement being in this case used, one of them revolving above the nose of the pedal lever.

(89) The action of this mechanism is easily explained. As the pedals are depressed or elevated the bowls are moved laterally, as previously described. The last of the series being in contact with the lever O causes it to oscillate, and, in consequence, the shorter lever jointed to the rod Q is moved. This motion is communicated to the chain F, which exerts a pull upon the strap guides, and raises or allows them to fall as described. One cardinal feature in this arrangement is the power of adjustment which is given at every point, the balance weight T being easily set to give the exact amount of pressure of the lever O upon the last bowl, while at the same time permitting it to oscillate without an excessive power being required. This makes the motion very sensitive, which is assisted by the size of the cones, and by placing the pedals on knife-edged supports instead of a shaft. Usually the cones are made about 4 inches diameter at the large end and 2¹/₂ inches at the smaller. In the machine, as made by Messrs. Platt, the cones are 8 and 5 inches diameter respectively at each end, and, as their velocity is high, a slight pull upon the strap vertically is sufficient to move it up or down the cones.

(90) A special arrangement, made by Messrs. Dobson and Barlow, is shown in Figs. 37 and 38 in elevation and plan. Here the pedals W W¹ are all of the same shape, and the last of the series W is not coupled to a connecting rod, as shown in Fig. 22. Instead of this, three bowls, R R T, are placed upon a pin which passes through the forked end of the small frame Z. The rollers R R roll in the groove in the box, and are provided with broad flanges which keep them in position laterally. The roller T is in contact with one edge of the last pendant W, and when the latter is pushed to one side it presses upon the roller and causes it and the cradle Z to move in the same direction. A pin in the other end of the cradle passes through the end of a lever Y, which fits between the fork in Z and passes through a hole in the cross-piece of the bowl-box. The thrust upon the rod Y is therefore given in the centre of the pendants, and these are not liable to be twisted. The rod Y is jointed to the L lever shown, which forms part of the series connecting the pedals and strap guide levers. As shown in the detached sectional view, Messrs. Dobson and Barlow employ between each pair of pendants three anti-friction bowls, U V U, which work loosely upon the pin X. The latter is made in the centre with a boss, eccentric to its main portion, and in this way the central bowl V is caused to engage with the pendant W, while the other two U engage only with the pendant W¹. The pin X cannot revolve by reason of being fitted into a square hole in one of the bowls sliding in the groove in the box, so that the relative positions of U and V are always maintained.

(91) In Figs. 39 and 40 a front and side elevation of the pedal regulator as made by Messrs. Asa Lees and Co. Limited, is illustrated. The pedals E are hinged at one end, and rest upon vertical rods J, the lower ends of which press on the extremities of the balanced plates B. Each of these is suspended on a larger plate C, of similar construction, which in turn rests on the extremity of a plate D. The latter is suspended by its centre from a lever, F, which is fulcrumed on a knife edge at H. The lever F is coupled in the manner shown to the strap guide lever I, which is moved by means of the horizontal bar shown, which slides upon guide runners. The cones A A¹, are placed horizontally, the advantage claimed for this position being that the strap has a much easier motion along the cones than is the case when the latter are vertical. It will be observed that the whole of the balanced plates are in equilibrium, and are suspended on the end of the lever F. Thus a slight movement of one of the smaller plates, B, is multiplied before it acts upon the lever F, and the regulation of the strap is thus rendered more sensitive.

(92) In Fig. 41 a side elevation of the driving gear used by Messrs. Asa Lees and Co. is shown. In this case the whole of the essential movements are driven by means of one endless rope. This plan obviates the difficulties which arise if a beater strap breaks and the feed continues, or if the delivery ceases from the same cause and under the same circumstances. In this case the lap attachment and cages are driven from the pulley D, the beater and the cones also by the same rope. The direction of the rope’s movement is indicated by the arrows, and a tightening screw is provided to keep the band in tension. On the shaft of the beater is a friction clutch, one-half of which is formed into a grooved pulley. By disconnecting the clutch, the beater can be stopped independently of the rest of the machine.

(93) Having thus described the principal methods of arranging the mechanism adopted by various machinists, there are one or two words to be said with reference to combined machines. These are very numerous and various, being arranged in several ways to suit the requirements of particular spinners. For instance, in Fig. 9, described in the last chapter, there is a combined machine, viz., an opener and lapper. The machine shown in Fig. 20 is an instance of a combined opener, scutcher, and lap machine. So, again, the machines shown in Figs. 13 and 14 are similar combinations, and in Fig. 8 is an example of a breaker feed combined with an opening cylinder—in different rooms but coupled by an air pipe—used as an aid in forming a stack of mixed cotton partially cleaned. In Fig. 13 a representation of the arrangement of a scutching room with a mixing room above it is given in section, and in Fig. 42 a plan of the mixing lattices. In this the bale breaker A delivers the cotton to a double ascending lattice B by which it is transferred to the series of longitudinal aprons C. Openings are placed above each bin E so that the cotton can be discharged into any of them at will. Alongside the mixing bins is a longitudinal lattice F, on to which the cotton is placed as it is taken from the stacks, and is carried to the porcupine feed table G. Immediately after being treated by that machine the material passes into the dust trunks D, over the dirt grids at K, to the cylinder of the opener H. The laps there formed are placed in the scutcher L, and those made in that machine are fed to M. The laps formed on the opener are fed to the scutchers, as shown in Fig. 22. In Fig. 43 a plan is given of one arrangement of a scutching room, showing a complete set of machines for dealing with Indian or other dirty cotton. For long stapled clean cotton, such as Egyptian, only the two machines enclosed within the dotted lines are necessary. Most of the figures dealing with these combinations are representations of actual arrangements carried out by Messrs. Platt Brothers. It is obvious that some plan must be adopted by which the supply of cotton must be stopped when the scutching machine is knocked off. If this was not the case, the air tubes and dust trunks would speedily become full, and there would be the risk of a breakdown when the machine was re-started. In view of this difficulty, Messrs. Platt arranged that when the machine is being stopped, the porcupine feed roller is stopped so much before the opener cylinder that the whole of the cotton delivered by it is drawn out of the dust trunks. Conversely, when the machine is being re-started, the feed mechanism is the first to begin operations, so as to ensure an ample supply of cotton to the cylinder, and thus avoid any thin places or failure in the resultant lap. This is a matter of some importance, as upon it depends very largely the regularity of the laps.

(94) It is of extreme importance to produce laps at an early stage, as they play a great part in effective spinning. Before dealing with this point a few words may be said about the necessity for care in feeding the cotton. The fibre is easily ruptured, more especially at the points, which, owing to their distance from the seed during growth, are often solid. It is conceivable that the cotton might be fed at precisely the same speed as that of the periphery of the beater blades. In that case it would simply pass through the machine without any treatment whatsoever. Or it might be fed so rapidly that the beater in its rotation would knock it off the end of the lap in tufts or lumps. As the blow of the beater is given transversely of the fibre, such a treatment would produce a large amount of broken fibre. It is, therefore, of importance to feed so that the cotton is neither broken by overfeeding or pulverised by underfeeding, and in fixing the right velocity the length of the fibre requires carefully taking into account. The conditions of successful and economical work are well known, and may be stated as follows: The blow given must be sharp, and not dragging; the beater blades must be shaped to detach, without rupturing, the fibres; the rate of the feed roller must be regulated to insure the thorough detachment of the material; and, finally, the cotton should not be struck from a sharply angular surface. It is, of course, impossible so long as revolving beaters are used to avoid bending the fibres, but it is quite possible to so shape the surface from which they are struck as to minimise the risk of damage.

(95) The various illustrations given of both opening and scutching machines show that it is the practice to form the cotton at as early a stage as possible into a lap. Not only is this course more convenient, but it is decidedly preferable where good work is required. In cases where it is the custom to eject the cotton from the opener in its opened condition, it is necessary to lay it on the feed lattice of the scutcher, either manually or by means of a lattice. A practice which is now almost obsolete is to weigh the cotton by means of scales adjoining the feed apron, and spread it on the latter by hand. Even with expert attendants, the risk of uneven feeding by this plan is great, and uneven feeding means unevenly-weighted laps as a result. By the exercise of a little care, and more especially if the piano-feed be fitted to the opener, a lap it produced on that machine the inequalities of which are much reduced. The author recently saw a lap, paragraph 52, produced on the combined feed, opener, and scutcher of Messrs. Platt, which was the first made on the particular machine employed, and which was remarkably regular in thickness. The same result has been seen in other cases, and by obtaining a regular sheet at this early stage many advantages arise. Whether an opener be employed in conjunction with a breaker scutcher or not, the formation of a lap is a great help to good work. Where such a combination exists, it is customary to fit pedal regulators immediately before the scutcher beater is reached, so that the inequalities existing in the sheet as it is taken from the first pair of cages are at once corrected. A reference to Figs. 10 and 20 will show this application fitted respectively to the opener feed and the scutcher beater.

(96) Whatever may be the practice with regard to the opener, the breaker scutching machine is invariably provided with the lap attachment, and the finisher scutcher is fed from laps. A reference to Fig. 22 will show that the machine is fed from three laps F, which are laid upon the travelling lattice apron G. The forward movement of this lattice unrolls the laps and delivers them to the feed rollers, they being prevented from moving forward by the rods through their centres, which press against the vertical projections on the lattice frame. It is often customary to use four laps instead of three, especially in passing them through the last machine.

(97) It will be apparent on reflection that the laps as produced will vary considerably in weight and substance. When first formed, and taken from the machine, each lap is weighed, and a record kept of its weight. In selecting the laps from which the finisher scutcher is to be fed, regard is paid to these variations. If one or two laps are under weight to a certain extent, while others are over it to a corresponding amount, the machine is supplied with both. As they are all fed at the same time, it follows that to a large extent the irregularity existing in one is corrected by the converse irregularity of another. This is, of course, a matter of degree, but roughly speaking, the correction is an effective one. By this system of doubling, as it is called, and by the regulation afforded by the pedal motion, the lap produced finally has rarely more variation than 5 per cent., and in many cases the variation does not exceed 1¹/₂ per cent.

(98) There must be with a machine fed from four laps, as there is even in the opener, a considerable amount of draught existing, for it is obvious that the resultant lap will be no heavier than one of those fed, and is in most cases lighter. That is to say, the lap is elongated so that an equal length of the finished lap weighs less than that of those fed. Thus the irregularities of thickness existing in any of the laps fed to the machine are diminished by the draught of the machine, and when this factor is combined with that arising from the treatment of four laps together, the result is found in the regularity stated. It is desirable to get as many doublings as possible, and where very good work is required the material is passed through three machines before the final laps are produced. This part of the subject is so easily understood that it is not necessary to further treat it.

(99) A point which is almost as important is the necessity for getting even selvedges to the laps when produced. The lap referred to in paragraph 52 had this feature, and there can be little doubt that the regulation of the air current plays an important part in this respect. It is of the highest importance that no thin places shall be found in the selvedges, as their effect is afterwards seen through every succeeding stage in spinning. Messrs. Platt Brothers have adopted a construction of their various machines, by which a gradually decreasing width is found in each of the series. Thus, if the opener produces a lap 48 inches wide, it will be fed to a scutcher 47 inches wide only, the lap so produced being that width. A similar or greater reduction is effected in the last of the series, the width being correspondingly reduced. In this way a very even selvedge is produced, with the consequent advantages.

(100) The weight of a lap is determined by weighing one or two yards. If it be afterwards desired to see what “hank” the lap is, the weight of the piece is obtained, and the weight of a pound calculated from it. That is divided into a constant number, obtained as afterwards described, and the resulting decimal gives the hank lap.

(101) The draught in a scutching machine takes place at the following points: 1st, between the feed lattice and rollers; 2nd, between the feed and the lap rollers.

(102) It only remains to be said that by the employment of air trunks and combined machines the finished laps can be produced by the aid of only two or three workpeople. The cotton requires no handling from the mixing room till the first lap is produced, and only then requires weighing and placing upon the finisher scutcher lattice table.