An Encyclopedia of the History of Technology part 85 pptx

PART FIVE: TECHNOLOGY AND SOCIETY 822 will run in a gentle circle, again to help keep it close to the reed. Then the points on the shuttle must be carved so that when it is held by them, the centre of gravity lies towards the back. It was probably not until after 1747, when Kay had to flee to France to escape the hostility aroused by his invention, that he made the final, and possibly crucial, modification. On earlier shuttles, the bobbin, or pirn, of weft was free to rotate on its spindle and the weft was pulled off from the side through a hole in the middle of the shuttle. With the faster speed of the flying shuttle and its sudden deceleration in the box, the pirn would have continued to rotate, causing a snarl in the weft. This fault was overcome by placing the pirn firmly on the spindle or skewer in the shuttle and drawing the weft off over one end and out through a hole at that end of the shuttle. The normal manner of winding the yarn on to the pirn was to traverse it from side to side along the face of the bobbin so that parallel layers were built up. Kay’s new method was to wind the yarn in short traverses at one end of the pirn to begin with, and to build these up into a cone. Then he continued winding on this short conical surface until the entire length of the pirn had been filled and he had made a cop. This method of winding was soon copied on the great spinning wheel (see p. 813) because then this cop could be put straight into the shuttle without rewinding. The flying shuttle became much more popular in Lancashire after 1760, when John Kay’s son Robert invented the drop box. Instead of a single box for the shuttle at the end of the slay, he introduced a tiered box holding at first two but later up to four shuttles. This could slide up and down, so that any shuttle could be lined up with the race. Shuttles with either different colours or different types of weft could be put on the shelves and the weaver could select which one he wanted by pressing a lever on the reed with his left hand. This invention helped to speed up the weaving of cloths like checks with their different colours which formed a large part of the Lancashire output. John Kay also made another contribution to textile technology when, around 1730, he substituted strips of thin metal instead of split cane in the reed. Pattern weaving Methods for speeding the selection of warp threads to make patterns were developed on the Continent, particularly in France, presumably through the demands of the luxurious royal court. Two things had to be developed for pattern weaving. First was a simple memory system in which the pattern could be stored so that it could be reproduced pick by pick. Then a method of lifting the appropriate warp threads and leaving the others down had to be devised to link up with the memory. Ideally, each warp thread ought to be selected individually. In 1725, Basile Bouchon invented a very ingenious apparatus consisting of a combination of hooks and needles, the lifting part, working in conjunction with a paper pierced with holes, the memory. The holes in the paper allowed TEXTILES AND CLOTHING 823 some needles to penetrate and lift the hooks, which they controlled. In turn these hooks lifted the warp threads to form the design. The spaces on the paper pushed back the remaining needles and so the hook linked with them, and their corresponding threads remained down. The advantage of this mechanism over the earlier draw boy system was that the pattern could be changed merely by replacing the paper. But the system was limited, partly because of the small number of needles it could accommodate and probably through the weakness of the paper. In 1728 another Frenchman, Falcon, invented a new arrangement with the needles placed in rows which permitted many more cords (the leashes, or lingos) to be used. The hooks were picked up on a series of crossbars called the griffe. He replaced the paper with a series of cards, each card representing one pick. The mechanism was moved to the side of the loom but still had to be worked by a second person. In 1745, Jacques de Vaucanson put the selecting mechanism on top of his unsuccessful power loom, but it was not until 1801 that Joseph-Marie Jacquard took out a patent for an improved figuring mechanism. The best features of earlier inventors were combined into a machine which needed only slight modifications to make it work properly. Jacquard took Falcon’s cards punched with holes like Bouchon’s paper, pressed against the needles by the pierced cylinder invented by Régnier, to select the pattern. He placed his machine on top of the loom, like Vaucanson, and arranged it so it could be operated by the weaver himself through a foot pedal. Although Jacquard was awarded a gold medal in 1804, his invention failed in the way it pressed the card against the needles. This was improved by Skola in 1819, and it was his Jacquard machine which finally solved the problem of repeating complex patterns in weaving (Figure 17.5). His apparatus was easily adapted for fitting on to power looms. THE INDUSTRIAL REVOLUTION Spinning machines All the new inventions which emerged during the eighteenth century for producing different types of fabrics more quickly precipitated a crisis: because all flax, wool and cotton still had to be spun on the single thread mediaeval spinning wheels, the supply of yarn became inadequate. It is difficult to estimate how much yarn a weaver needed, or how much a spinner could produce, because spinning and weaving the finer counts took much more skill and time. Different writers give various estimates of the number of spinners required to keep one weaver at work, ranging from four to eight or even ten to twelve. If, as a rough average, we assume that the output of about eight PART FIVE: TECHNOLOGY AND SOCIETY 824 spinners was needed per weaver, then the weaver’s difficulties in securing regular supplies will be appreciated. Some accounts of the period around 1760 say that weavers had to walk many miles to find spinners, and had to pay them at a higher rate or give them presents in order to have the yarn ready in time for the cloth to be woven within the promised period. Often the spinning was of poor quality, the yarn being lumpy and irregularly twisted. In such circumstances, it is not surprising that many people were trying to invent a satisfactory spinning machine. Many people must have looked at the silk throwing machines and wondered if the spinning of cotton or wool could be mechanized in the same way. Thomas Cotchett tried to build a water-powered mill with Italian silk throwing machines at Derby in 1702. He failed, and it was left to the half- brothers Thomas and John Lombe to establish the first successful power- driven English textile mill in 1717 at Derby beside Cotchett’s earlier site. Spindles and flyers with reels above them were placed in three tiers around the periphery of a large circular frame. The waterwheel drove large horizontal wheels inside the frames which turned the spindles by rubbing against their rims. This twisted the silk which was wound on to the reels, also turned by the waterwheel. Similar machines were introduced to a mill at Stockport in 1738, so people in the Lancashire area would have heard about them. The earliest claimants to making a machine for spinning cotton are Lewis Paul and John Wyatt who took out two patents in Paul’s name in 1738 and Figure 17.5: The Jacquard loom. The weaver is working the Jacquard foot pedal with his right leg while his wife is winding the pirns for the shuttle. TEXTILES AND CLOTHING 825 1758. The variety of ideas included in their first patent suggests a machine still in the experimental stage. Little work was done after 1743 and Paul died soon after the second patent had been granted. Paul and Wyatt built a circular machine somewhat on the lines of the silk throwing machines. They tried rollers for drawing out the rovings and wound the yarn on to bobbins past flyers. They failed, probably because the rollers they used were too large in diameter. They attempted to use the principle of spindle drawing, where the cotton was stretched to draw it out between the rollers and the spindle. Where this was done with a flyer, the cotton would have been drawn out unevenly and irregularly twisted, with many breaks. Various mills were established with these machines but none lasted long. Their machine was tantalizingly near to success, and might well have been a commercial proposition for doubling a thread, but it was based upon the wrong principles for spinning cotton. The spinning jenny It was some time before anyone else embarked on a machine for spinning after the failure of Paul and Wyatt. One day in about 1763, a spinning wheel in James Hargreaves’s home near Blackburn, Lancashire, was knocked over accidentally. As it lay on its side, still rotating, it inspired him to try making a spinning machine. To understand the principles of the spinning jenny (Figure 17.6), it is necessary first to understand one method of spinning by hand. When spinning with the great wheel, it was possible for the spinner to grasp firmly the sliver or roving, leaving three of four inches of unspun fibres between the fingers and the spindle. Her fingers, still tightly clamped, were pulled away from the spindle, drawing out (drafting) the fibres. If the spindle was rotated gently at the same time, the fibres cohered as they were pulled out. The roving could be drawn out into a fine yarn because the twist ran into the thinnest places first, binding them together, while the thicker parts were more loosely twisted and so could continue to be drawn out. If the spinner did not twist enough, the yarn disintegrated, while if she twisted too much, it locked together before it was drawn out finely enough. When it was fine enough, she had to put in more twist to hold it all firmly together, and then she could back off and wind on in the usual way. To spin like this required a very sensitive touch and would seem impossible to mechanize, yet it was this method which Hargreaves used on his jenny. He placed the spindles at the far end, slightly inclined from the vertical towards the spinner. They were driven by bands from a large wheel turned by the right hand. Instead of the spinner’s fingers, he had a sliding wooden clamp, or clove, to hold the eight rovings he spun on his first machine. The left hand drew back the clove as the yarn was being spun and pushed it forward to wind on. A length of roving was released through the clove as it was drawn away from PART FIVE: TECHNOLOGY AND SOCIETY 826 the spindles. The clove was closed again and the roving drawn out while the spindles were twisted gently. When the clove was nearly at the end of the slides, and the roving drawn out fine enough, the spindles were rotated quickly to put in twist to lock the fibres together. After this, the spindles were reversed to back off and finally turned once more in the spinning direction to wind on as the clove was pushed back in again. The yarn was guided on to the spindles by a faller wire operated by one foot. Only a soft, lightly twisted yarn could be spun on the jenny because, when the yarn was wound on, a short length was left between the tips of the spindles and the clove. When the next length of roving was pulled through the clove, the twist from the yarn would run into the roving and, if it had been twisted too much, would lock the fibres in the roving and prevent it being drawn out. Therefore the yarn spun on the jenny was really only suitable for weft and not warp. By 1770 the number of spindles on the jenny had been increased to sixteen, but was soon raised to 80 or even 120. One person working an early jenny could supply one weaver. The jenny was cheap to produce, being mainly of wood, and comparatively small, so it was used principally in the spinners’ homes. James Hargreaves was born in Oswaldtwistle in Lancashire; son of a poor hand loom weaver, in about 1720. After he had developed his machine, he was Figure 17.6: A replica of the Hargreaves spinning jenny. TEXTILES AND CLOTHING 827 forced to leave owing to the wrath of the local people who thought it would create unemployment. He moved to Nottingham and set up a factory producing yarn for the hosiery industry. Although he patented his machine after his arrival in Nottingham, he was unable to enforce the patent rights. He died in 1778, a disappointed man, for, although he himself never made a fortune, others did with his jenny and, in the end, he was forced to install Arkwright’s waterframes in his factory because the jenny did not produce satisfactory yarn for the hosiery industry. The waterframe In 1769, Richard Arkwright of Preston, Lancashire, patented a spinning machine which had rollers for drawing out the cotton and flyers and bobbins for spinning. Arkwright may have been familiar with the flax spinning wheel (see p. 814) from his childhood and, from its continuous action, realized that it was the obvious type to try to mechanize if some mechanical action could be found to copy the spinner’s fingers. The importance of the flax wheel lies not only in its continuous spinning principle but also in one of the ways in which spinners drew out the fibres on it. While the fingers of one hand held the sliver, the fingers of the other held the spun yarn and pulled out the right number of fibres from the sliver. Then the spun yarn was released, allowing the twist to run into the newly drawn out fibres. This distance the fingers could be pulled apart, the drafting zone, was determined by the staple length of the fibres (Figure 17.7). In his prototype machine, Arkwright placed four spindles with their flyers and bobbins vertically near the bottom. The friction of the spindles turning caused the bobbins to rotate as well, so they were slightly retarded by light string brakes. At the top, he placed the vital drawing rollers which have barely changed up to the present day (Figure 17.8). There were four sets, each consisting of pairs of rollers. The top roller of each pair was covered with leather, and was kept firmly in contact with its counterpart below by a weight. Figure 17.7: Principles of drawing out the fibres by hand. Drawing by Richard Hills. PART FIVE: TECHNOLOGY AND SOCIETY 828 The bottom rollers were made from metal and wood, and had flutes cut along them. These lower rollers were connected together by gearing so that one shaft could turn them all. The back pair of rollers, where the thick cotton roving entered, rotated slowest and each succeeding pair turned faster. In this way, the roving was drawn out until the correct number of fibres was passed out between the nip of the front rollers, where the twist from the spindle locked them firmly together and made the finished yarn. Arkwright did not have the skill to make this machine himself, so he employed John Kay, a Warrington clockmaker, to help him. Earlier Kay had helped Thomas Highs with a spinning machine and, according to one version of the story, Kay showed Highs’s machine to Arkwright, who copied it and took all the credit for the invention. However, Arkwright added two vital contributions. First, he realized that the successive pairs of rollers must be set the correct distance apart to correspond with the staple length of the fibres being spun. The drafting zone must be a little longer than the staple length. If the rollers were set close enough for two pairs to grip the same fibre, this fibre could not be drawn past its neighbours and would break. If the rollers were set too far apart, so that the fibres floated between them and were not gripped by either, the drawing would be uneven and lumpy and a broken yarn could result. Ideally, all the fibres should be the same length and the rollers set a little further apart than this length. In order to hold the fibres tightly in the nip of the roller, Arkwright made his second contribution. He hung weights on the top rollers so that they pressed firmly against their lower counterparts. Paul and Wyatt (see p. 824) had not weighted their rollers and, in addition, did not seem to have realized the vital importance of the staple length. Without the weights, the twist will run back between the rollers and lock the fibres together in the drafting zone so they cannot be drawn out. By January 1768, Arkwright had returned to Preston and built a spinning machine in the old Grammar School. He could have made more and sold them locally, like Hargreaves, or he could have allowed his machines to be built on a small scale and used in cottages, for they could have been turned quite easily by people in their own homes. Instead, Figure 17.8: Principle of the cotton drawing rollers patented by Richard Arkwright in 1769. Drawing by Richard Hills. TEXTILES AND CLOTHING 829 Arkwright’s business sense told him that his machine had much greater potential because it could be set up in factories and driven by power. In 1769, Arkwright and his two partners, John Smalley and David Thornley, were granted a patent and they moved to Nottingham where they established a factory powered by a horse. Then the partnership was enlarged with the addition of Jedidiah Strutt and Samuel Need, a Nottingham banker. A waterpowered mill was built at Cromford, Derbyshire, in 1771 which was the first spinning mill as we know them today and here the final development of the spinning machine and of the preparatory machinery (see below) was carried out. Because the Cromford mill was driven by a waterwheel, Arkwright’s spinning machine became known as the waterframe (Figure 17.9). The drag of the bobbin meant that only a hard-twisted yarn of medium counts Figure 17.9: An early Arkwright waterframe, possibly dating from 1775. PART FIVE: TECHNOLOGY AND SOCIETY 830 could be produced on the waterframe. This was suitable for the warp of coarser types of cloth, so at last it was possible to weave in England cloth made entirely from cotton: previously most warps had been linen. Yarn was spun on the waterframe more cheaply than by the spinner at home and soon there was an enormous demand for it as both home sales and exports boomed. Carding machines Having produced a successful spinning machine, Arkwright needed to develop a series of preparatory machines in order to start factory production. On the waterframe, he fitted a cam motion to raise and lower the bobbins so that they were filled evenly in place of the earlier hecks (hooks) on the flyers. For the waterframes to be able to spin a continuous yarn, each spindle had to be supplied with a continuous length of roving which, in turn, had to be made from a continuous length of carded sliver. In other words, having mechanized one part of the spinning sequence, it was necessary to mechanize all the others to maintain the momentum. This is typical of the sudden upsurge called the Industrial Revolution, during which one invention stimulated another in quick succession. Once the balance of the old domestic industry had been upset, invention followed invention until textile production was completely industrialized. Over the years there had been few improvements to carding. In 1750, William Pennington had patented a machine for making the holes in the leather backing through which the wires were inserted and, soon after that, Robert Kay developed a machine for cutting, bending and inserting the wires or points through the leather. Larger cards, sometimes called stock cards, were tried. The lower card was firmly fixed to a table and the upper one might be suspended by a series of pulleys and weights to help ease the load. Paul and Wyatt had found that it was necessary to mechanize carding to keep their spinning machines supplied, but they did not really progress beyond an enlarged hand or stock card. A more significant advance was made by D.Bourn in 1748 when he patented a carding machine on which the fibres were passed from one cylinder to another. The surfaces of the cylinders were covered with card clothing and, while it was easy to take the fibres off one set of points by another, Bourn did not solve the problem of taking the fibres off the final set which had to be done by hand with a needle stick. Other people tried to make carding engines, but it was Arkwright who solved the problem and patented the solution in 1775. Descriptions and pictures often different machines for preparing cotton were given in the patent, but some were of little significance except that they show that Arkwright was trying to mechanize all the preparatory processes. His opening and cleaning machines were never constructed and, at Cromford, women beat the cotton with sticks to open it and then picked out the dirt by hand. The cotton had to be fed into the TEXTILES AND CLOTHING 831 carding engine, which Arkwright did by laying a length of cloth on a table and spreading cotton evenly on the top. Then both were rolled up and put at the back of the carding engine. The fibres were fed in as the cloth was unrolled and left on the floor. Later the cloth was shown to be unnecessary. To give a continuous sliver from the carding engine, the whole of the surface of the cylinders needed to be covered with points. Arkwright prepared a long narrow strip of card fillet which he wound in a spiral round the cylinder so there were virtually no gaps between the points. The type of carding engine which soon became the standard pattern had a main cylinder of large diameter. The cotton was pulled out between the points on its surface and much smaller cylinders set round the upper circumference. Later these cylinders were replaced by flat cards to give a better coverage. A second cylinder, the doffer, somewhat smaller than the main one, rotated at a different speed to take the carded cotton off the main one. Arkwright solved the problem of removing the cotton from the doffer with his crank and comb. Across the front of the doffer was placed a strip of metal called the comb, because the bottom edge was cut into fine teeth. It was connected to a crank which raised and lowered it so that the teeth pushed the cotton off the wire points of the doffer. The cotton came off in a broad gossamer web which was collected into a single roll, passed through a pair of rollers and allowed to drop into a can placed in front. The drawing frame The sliver coming from the carding engine had many irregularities and was too thick to be fed straight into the rollers on the waterframes. Therefore it had to be made thinner by being passed through drawing frames. Four or six slivers were passed through a set of rollers and were drawn out in the same ratio as the number fed in, so that one sliver of the same thickness appeared at the other end but four or six times as long. Because the thickness of the original slivers was averaged out, this sliver would be more even than those fed in and also the bent fibres were straightened out. After passing the slivers through two or even three drawing frames, Arkwright had a good quality sliver, but it was still too thick for his waterframes. He could reduce it by passing it through more rollers, but the thinner sliver had no cohesion and fell to pieces when handled. Arkwright’s patent of 1775 shows that he tried three different ways to overcome this problem, but, although he produced a reasonably satisfactory solution, a more adequate machine was not developed until after his death. His solution was to pass the sliver through a set of rollers and allow it to fall into a rotating can so the sliver was twisted as it entered and coiled against the side by centrifugal force. The sliver was twisted enough to keep it together but not enough to prevent it being drawn out. These rovings had to be wound on bobbins by children to fit the waterframe. . in one of the ways in which spinners drew out the fibres on it. While the fingers of one hand held the sliver, the fingers of the other held the spun yarn and pulled out the right number of fibres. surfaces of the cylinders were covered with card clothing and, while it was easy to take the fibres off one set of points by another, Bourn did not solve the problem of taking the fibres off the final. the paper. But the system was limited, partly because of the small number of needles it could accommodate and probably through the weakness of the paper. In 1728 another Frenchman, Falcon, invented