IELTS Academic Reading Practice Test 195

For most of human history, clothing was made by hand. A single shirt contains thousands of stitches, and a skilled seamstress working steadily with a needle and thread might finish one in a long day of labour. Garments were therefore expensive, and most people owned few of them. The idea of a machine that could form a stitch automatically attracted inventors for well over a century, but the difficulty was considerable. A needle pushed through cloth has to carry thread with it, and that thread must then be secured on the far side so that the stitch holds.

The first patent for such a device was taken out by an Englishman, Thomas Saint, who in 1790 described a machine that used an awl to pierce leather or canvas and a needle to pass a thread through the hole. The drawings that accompany the patent are detailed, yet no machine from that period is known to have survived, and it is unclear whether one was ever built. When a replica was constructed from Saint's drawings in the 1870s, it would not sew until it had been altered, which suggests that the original design was never tested in practice.

Forty years later a French tailor, Barthélemy Thimonnier, came much closer. His machine of 1830 was made largely of wood and used a single thread and a barbed needle, which formed a chain of loops rather than a tight stitch. The advantage was speed and simplicity; the weakness was that the chain could be pulled undone. Thimonnier obtained a patent and, with financial backing, set up a workshop in Paris to sew uniforms for the army. In 1831 a crowd of tailors, convinced that such machines would destroy their livelihoods, broke in and smashed the equipment. Thimonnier later tried to sell his invention in England, failed, and died in poverty.

American inventors attacked the problem in the 1830s and 1840s. Walter Hunt, a prolific mechanic in New York, built a machine that produced a lockstitch — two threads interlocking in the middle of the fabric, so that the seam held firmly — but he decided not to patent it, apparently fearing the effect on employment. The patent went instead to Elias Howe, who was granted one in 1846 for a machine that combined three features still found in modern machines: an eye-pointed needle, a shuttle carrying a second thread underneath the cloth, and a mechanism for advancing the fabric between stitches.

Commercially, Howe's machine was a failure. He could find no American manufacturer willing to pay for the rights, and after a stay in England, where he licensed the invention to a maker of corsets for a modest sum, he returned home in 1849 to discover that others were making and selling machines that used his ideas without permission. He borrowed money and took them to court.

The most successful of those rivals was Isaac Merritt Singer, a former actor and mechanic. Singer's machine of 1851 was not the first to work, but it was the first designed to be practical in a workshop. Its needle moved vertically, suspended from an arm that overhung the table, and a presser foot held the cloth down while a toothed wheel fed it forward after each stitch. The rotating hook, invented by Allen B. Wilson, replaced the shuttle in many machines and allowed them to run faster with less tangling. Earlier machines had needed one hand to guide the cloth and another to turn the wheel; Singer's could be driven by a treadle, leaving both hands free.

Howe's lawsuits were settled in 1854, when the manufacturers agreed to pay him royalties on every machine they sold. Two years later the principal firms went further and pooled their patents in what became known as the Sewing Machine Combination. Any newcomer who wished to build a machine had to pay a licence fee of fifteen dollars and accept the terms of the group, which controlled the essential mechanisms until the last of the original patents expired in 1877. The arrangement kept prices high and innovation slow, but it gave the industry stability.

Sales then depended less on engineering than on marketing. Singer's business partner, Edward Clark, introduced a system by which households could buy a machine in small instalments rather than paying the full price at once, an early example of hire purchase that made the equipment reachable for families of modest means. The company sent out agents, many of them women, to demonstrate the machines in homes and village halls, and it built factories in Britain and elsewhere in Europe. A treadle model needed no power supply, and from 1889 an electric motor was available for those with electricity.

The consequences reached far beyond the household. In factories, machines driven by steam made it possible to cut and sew garments in large quantities, and the ready-made clothing industry grew rapidly in the second half of the nineteenth century. Much of that work was done by women in cramped rooms for very low pay, and the same machine that had promised to lighten labour at home also made possible the sweatshop. Few inventions have changed both the family and the factory so thoroughly.

Cross-laminated timber, usually shortened to CLT, is a panel made by gluing together layers of sawn softwood. Each layer, known as a lamella, consists of boards laid side by side, and successive layers are placed at right angles to one another. The result is a solid slab, typically between three and nine layers thick, that can serve as a wall, a floor or a roof. A single panel may be three metres wide and more than sixteen metres long, so one piece can form the entire floor of a room or the whole side of a house.

The product was developed in Europe in the 1990s, largely through research at the Graz University of Technology in Austria and at institutes in Germany. Early industrial production began in Austria and Germany, and for a decade the material remained a specialist product used mainly in those countries. Since about 2010, however, mills in Scandinavia, Italy, Canada and the United States have begun to manufacture it, and worldwide output has grown quickly, although it remains small beside the quantities of concrete poured each year. Mills now operate in Australia, Japan and New Zealand as well, and several European countries have more than one.

The principle of cross-lamination is the same as that of plywood, which is simply much thinner; the difference is one of scale and structural role. Wood is strong along the grain and weak across it, and it swells and shrinks far more in one direction than in the other as moisture changes. Gluing alternate layers at right angles means that each layer restrains the movement of the one beneath it. The panel therefore stays flat and gains strength in two directions at once, so that it can span between supports as a concrete slab does, rather than only in one direction like a beam. Panels are cut to shape by computer-controlled machines, and openings for windows, doors and services are formed in the factory.

Because the panels are made in a factory, work on site is mostly assembly. Components arrive by lorry in the order in which they will be needed, are lifted into position by crane and fixed together with screws and metal brackets. A small crew can erect a storey in days rather than weeks. The panels are also light for their strength, so the foundations can be lighter and the groundworks cheaper than for an equivalent concrete frame. Sites are quieter, generate less waste and require fewer deliveries.

Timber has an environmental advantage that no other structural material shares. A tree takes carbon dioxide out of the atmosphere and stores the carbon in its wood, and that carbon remains locked in a building for as long as the building stands. Cement, by contrast, accounts for a substantial share of global industrial emissions, and steel is also energy-intensive. Replacing concrete with timber in the frame of a building therefore avoids emissions twice over: less is produced, and some is stored. The calculation holds only if the forest is managed so that new trees replace those cut. Where forests are replanted or allowed to regenerate, the supply of timber can be maintained indefinitely; where they are cleared, the benefit disappears.

Fire is the objection that every timber engineer meets first. Thick timber does not behave like kindling: as the outer surface burns it forms a layer of charcoal that insulates the wood beneath and slows further burning at a predictable rate. Engineers can therefore specify a sacrificial thickness that is expected to char, leaving a sound core to carry the load for the period required by the regulations. Furnishings and contents, rather than the structure, are usually the main fuel in a fire, and many timber buildings are fitted with sprinklers as well.

There are real limitations. Wood absorbs water, so panels must be kept dry on site and protected from rain until the building is closed; a frame that becomes soaked may have to be dried out at considerable cost. Because CLT is light, sound travels through it easily, and floors need added mass, floating screeds or resilient layers if noise between flats is to be controlled. Some concern has focused on the adhesives used to bond the layers, since certain formulations release small quantities of formaldehyde, although low-emission products are now on the market. Building codes in many countries still restrict the height of timber structures, and the number of suppliers able to make large panels is small, which keeps prices high.

Height records have fallen steadily. Brock Commons, an eighteen-storey student residence at the University of British Columbia in Canada, was completed in 2017 and was then the tallest mass-timber building in the world. It was followed in 2019 by Mjøstårnet in Norway, a tower of eighteen storeys and more than eighty metres, and in 2022 by Ascent, a twenty-five-storey block in Milwaukee in the United States. The Canadian and American examples rely on a concrete core for stability, while the Norwegian tower is supported by glue-laminated columns and beams.

Research is now directed at the questions that limit the material's use. Engineers want to understand how the connections between panels behave in an earthquake, since a timber frame is light and can be designed to rock and absorb energy rather than resist the movement rigidly. Others are testing spans long enough for offices and schools, sensors that report moisture inside a sealed panel, and methods of dismantling a building so that its panels can be used again. If a panel can be unscrewed and reused, the carbon it stores stays out of the atmosphere for even longer.

In April 2012, audiences at the Coachella festival in California watched a rapper who had died sixteen years earlier perform beside two living stars. The figure of Tupac Shakur appeared to stand on the stage, turned, spoke to the crowd and vanished. Within days the clip had been watched millions of times, and promoters around the world drew an obvious conclusion: there was money to be made from bringing the dead back. Since then, figures of Michael Jackson, Whitney Houston, Roy Orbison and Maria Callas have been put on stage, and further names are announced every year.

What the audience sees is not, strictly speaking, a hologram. A true hologram is a recording of the pattern made when two beams of light interfere, and it reproduces a three-dimensional image when it is illuminated; the technique exists, but it is not what these shows use. The stage figures are produced by an illusion known as Pepper's ghost, which was described in print in the sixteenth century and became a fixture of Victorian theatre. A sheet of glass or film is angled across the stage and reflects a bright image from a hidden screen, so that the audience sees the reflection apparently standing in the space in front of them. The trick works only from a particular part of the auditorium, which is why the seating has to be arranged with some care.

The commercial logic is easy to understand. Concert audiences are growing older, and much of the music that fills arenas today was written by people now in their sixties and seventies. Nostalgia is one of the most dependable products in the entertainment industry, and a performer who died young has an advantage over a living one: the catalogue is fixed, a reputation cannot be damaged by a poor album, and the supply of appearances can be extended indefinitely. Estates, which earn fees from licensing, have generally been willing partners.

Whether audiences are deceived is a subtler question. Nobody who buys a ticket seriously believes that the singer has returned from the grave. Yet an audience can be moved by an illusion while remaining aware of it, and the emotion is genuine even when its cause is not. Theatre has always depended on exactly that arrangement.

The objection that troubles me is different, and it concerns what a performance actually is. A concert is not a set of sounds reproduced in the right order; it is an exchange. The performer watches the room, waits a beat longer than usual, answers a shout from the crowd with a joke. The dead can do none of this. What the audience sees is an elaborate puppet, assembled from photographs, recordings and the guesses of animators, moving exactly as its makers decided it should move. It can repeat what the artist once did; it cannot improvise. The figure cannot be surprised, and it cannot surprise us. What is lost is not the songs but the risk that makes a live show worth attending.

Then there is the question of consent. A living performer can refuse to take part, and can change their mind; someone who has died can do neither. The right to decide therefore passes to whoever administers the estate, which may be a family, a lawyer or a company that has bought the rights. Some relatives have refused to allow such shows, and at least one planned tour was postponed indefinitely before it reached the stage. Others have cooperated enthusiastically, and it would be wrong to assume that money always wins.

Defenders of the practice point out that we are surrounded by images of the dead. Photographs and recordings are sold, films are re-released, and few people object when a singer's unfinished album is completed by others. But a recording is understood as a recording: the audience knows that the performance happened in the past, at a particular moment, and the technology that carries it is transparent. A figure on a stage is presented as present, in the room, now, and that is a different claim. The comparison shows that the dead have long had careers; it does not settle whether they agreed to this one.

The industry could do much better than it does. Three conditions seem to me reasonable. The first is disclosure: before the show begins, the audience should be told exactly what it is about to see and how the figure was made. The second is consent, given while the artist was alive or by those the artist trusted. The third is restraint: a figure should not be made to advertise products or to sing songs the artist never sang, and it should not be placed beside living performers in a way that suggests an encounter which never took place. None of these conditions is radical, and several promoters already meet them without being asked.

None of this will stop the technology. The images will become sharper, the movements more convincing and the cost lower, and in a few years the question will not be whether a dead singer can appear but which dead singers are available. Banning the shows would be both impossible and unnecessary; at their best they can serve as a public act of remembrance. What matters is that the audience is not misled, and that the person whose face is being borrowed had the chance to say no. That is a modest demand, and it is one the industry could satisfy tomorrow if it chose.