IELTS Academic Reading Practice Test 502

For about six hundred years, one of the most dependable ways of measuring a period of time has been a pair of glass bulbs joined at a narrow neck, with a quantity of dry sand trickling from the upper one to the lower. The hourglass, or sandglass, has no moving parts, needs no fuel and works equally well in daylight or darkness. What it does not do is tell the time of day. It measures an interval, and it does so only if someone remembers to turn it over when the last grains have fallen.

Nobody knows who made the first hourglass. The device became possible only when glassmakers could blow clear glass into rounded shapes of even thickness, a skill that developed in the glasshouses of northern Italy and elsewhere in Europe during the Middle Ages. The earliest evidence of the instrument is a painting: Ambrogio Lorenzetti's fresco of good government, completed in Siena's Palazzo Pubblico in 1338, includes a small hourglass held by a figure representing Temperance. Written references become more numerous in the following century, and by the 1400s sandglasses were being made in several European cities.

Before that, the standard device for measuring intervals indoors was the water clock, in which water dripped through a small hole. Water clocks were heavy, needed constant refilling, and behaved badly in cold weather, when the water could freeze. The hourglass had none of these weaknesses. It could be carried, knocked over and set going again, and its accuracy did not depend on the season. Its other great rival, the sundial, was useless at night and on cloudy days.

The sand itself was a matter of considerable skill. Makers used whatever local material flowed most evenly: ground eggshell, powdered marble, lead dust, iron filings or the ash of burnt wood. The grains had to be dry, hard and of similar size; a mixture of coarse and fine particles would clog the neck or run unevenly. The material was usually washed or baked and then sieved before use, and some workshops guarded their recipes closely. Because the rate of flow depends on both the grains and the width of the neck, every glass had to be adjusted individually.

It was at sea that the sandglass found its most important use. From the fifteenth century, European ships carried sets of glasses, often of half an hour, and a member of the crew was given the task of turning them and striking the ship's bell as each one ran out. The glasses divided the watch into equal portions, which helped keep order during long nights, and they were used together with the log, a weighted line thrown astern to measure speed. The number of knots counted while the glass emptied gave the ship's speed in knots.

On land, the hourglass governed sermons, lectures and legal arguments. Many churches installed a glass on an iron bracket beside the pulpit, so that a preacher could see how much of the allotted hour remained, and a few of these glasses are still in place. Universities used glasses to time disputations and courts to limit speeches. Cooks used small ones to time eggs, and craftsmen used them to measure the cooling or hardening of materials.

Making a sandglass required patience as well as skill. Two bulbs were blown and joined at a narrow waist, leaving a small opening through which the sand could be inserted. The material was dried thoroughly, because damp sand clumps and stops flowing, and poured in through a funnel. The neck was then fitted, and the glass was checked against a clock: if the sand ran through too quickly the neck was narrowed, and if too slowly it was widened. Finally the opening was closed with a plug of wax. Even then the contents might be affected by moisture in the air, and many glasses had to be refilled from time to time.

The hourglass had obvious limitations. It could not show the time of day, it had to be watched, and its accuracy was only as good as the regularity of its sand and the condition of its neck, which wore wider with use. Nor could it be adjusted without being opened. Above all, the interval it measured was fixed when it was made: a glass that ran for an hour could not be persuaded to run for fifty minutes. For most purposes none of this mattered, since people wanted to know how long something had taken rather than what time it was.

At sea, the sandglass was eventually displaced by something more ambitious. The problem of finding longitude depended on knowing the exact time at a reference port, and in the eighteenth century the English carpenter and clockmaker John Harrison built timekeepers that kept good time on a rolling ship. His celebrated watch, completed in 1759 and tested on a voyage to Jamaica, performed far better than anyone had expected, and once accurate chronometers became affordable navigators no longer needed a boy turning a glass every half hour.

The sandglass never disappeared entirely. Small versions survived in kitchens as egg timers, in board games and gymnasiums, and its shape remains a familiar symbol. In vanitas paintings popular in the sixteenth and seventeenth centuries, which set out to remind viewers of the shortness of life, an hourglass beside a skull served as a warning of death. The same image, emptied of its religious meaning, now appears on computer screens, where a turning hourglass tells the user to wait.

Watch two people talking and you will see more than their mouths move. Their hands rise, shape imaginary objects, cut the air and beat time, usually without the speakers noticing what they are doing. These movements are known as co-speech gestures. They are not the formal signs of a sign language, and they are not emblems either: a wave or a thumbs-up carries a meaning of its own and can replace a word, whereas a co-speech gesture has no fixed sense and takes its meaning from the words it accompanies. The timing is remarkably precise; a gesture typically starts a fraction of a second before the word it relates to is spoken.

The most influential attempt to sort these movements into categories was made by the American psycholinguist David McNeill, who distinguished four broad kinds. Iconic gestures depict something concrete, such as the shape of a staircase or the action of opening a bottle. Metaphoric gestures stand for abstract ideas, often by presenting them as objects held in the palm. Deictic gestures point, either at something present in the room or at a patch of air that has been given a meaning earlier in the conversation. Beats are small rhythmic flicks of the hand that mark emphasis or the structure of what is being said, and most speakers mix all four kinds within a few sentences.

For a long time, gestures were assumed to be a form of communication, a helpful extra channel for the benefit of the listener. The evidence for this is weaker than one might expect. People gesture copiously on the telephone, when nobody can see them. People who have been blind since birth gesture when they speak, and they continue to do so when their listener is blind as well. If gesture existed only to pass information to another person, neither behaviour would make sense. It appears instead to be bound up with the activity of speaking itself, and to be produced whether or not an audience is present. Speakers gesture least when reading aloud from a prepared script, and most when describing something they must work out as they go.

Further evidence comes from children. The psychologist Susan Goldin-Meadow and her colleagues noticed that children often make a gesture that conveys different information from the words they are using at that moment: a child may say that the amount of water in a row of glasses has not changed while indicating with the hands that it has. Such mismatches are not errors. They appear to mark a transitional stage in understanding, and children who produce them are more likely to benefit from instruction on the task than children whose speech and hands agree. The hands, it seems, can express an idea before the words are ready.

Experiments with adults point the same way. In one series, participants were asked to explain a mathematical problem while also remembering a list of items; those allowed to gesture recalled more of the list than those whose hands were restrained. Other studies have found that people describing a spatial layout, such as the route through a building, speak more fluently when their hands are free than when they are holding something. The usual interpretation is that gesturing lightens the load on the speaker's memory, carrying part of the information in the body rather than in words, and freeing limited mental resources for the sentence being constructed.

Why this should be so is disputed. One suggestion is that gesturing helps speakers to find words, so that the hands are part of the retrieval system rather than a message to anyone else. Another is that the motor system is recruited to hold spatial relationships that language handles poorly. Neither account explains every result, and the effects measured in experiments are often modest. Several attempts to repeat well-known findings have produced weaker results, and the field has been criticised for relying on small samples of students in laboratories rather than on talkers going about ordinary life. Neuroscience has so far added little, since activity in the areas that control hand movement during speech does not by itself show what the movement is for. The honest answer is that the mechanism remains uncertain.

None of this means that listeners ignore gestures. They read them, though not always accurately. When the hands and the voice conflict, adults tend to trust the voice, while young children often trust the hands, which is why a teacher who gestures while explaining a new idea can either help or confuse. Gesture also varies between cultures: speakers of some languages gesture more often and more expansively than others, and the same movement may be read differently in different countries. Listeners regularly pick up details from a speaker's hands that were never put into words, without being able to say where the information came from.

The practical implications are beginning to be taken seriously. Teachers are encouraged to gesture deliberately when introducing abstract ideas, and producers of educational videos are advised to keep the speaker's hands in shot rather than filling the screen with graphics. Surgeons and pilots, whose working conditions leave little room for the hands to move, are taught to compensate by speaking more explicitly. The claims should not be overstated. Gesture is a support to speech rather than a substitute for it, and nobody has shown that waving the hands can rescue an idea that has not been thought through.

Few areas of corporate policy have changed as quickly as the reporting of greenhouse gas emissions. Twenty years ago, publishing an annual figure for a company's carbon dioxide was a voluntary gesture, undertaken mainly by firms that wished to be seen as environmentally responsible. Today, listed companies in the European Union must do it, a global set of standards exists to guide them, and several other jurisdictions are bringing in their own rules. Whether this shift from invitation to obligation is wise remains genuinely contested.

Reporting begins with a distinction that is now standard. Emissions are divided into three categories, or scopes. The first covers fuel burned on a company's own premises and by vehicles it operates; the second covers the electricity, heat and steam it buys. Both are comparatively easy to count, from fuel bills and meter readings. The third, and much the largest for most firms, includes everything that happens in the supply chain and in the use of the products sold: the emissions of a steelmaker's customers, for instance. Scope three figures are estimates built from industry averages, and their accuracy is widely doubted.

The main argument for compulsion is that investors cannot judge a company's exposure to climate risk unless they have comparable numbers. Voluntary reporting produced a patchwork in which the same activity was measured, and reported, in different ways. Institutional investors have therefore pressed for a single set of rules. Standard-setters responded: an international board created in 2021 published its first climate disclosure standards in 2023, and the European Union's own directive requires large companies to report against detailed criteria. For the first time, an investor in one country can look at a company in another and make a reasonable comparison.

Some economists frame the issue in terms of information. A company knows far more about its own operations than any outsider, and if it is not obliged to publish what it knows, the market will price its shares on guesswork. Mandatory disclosure corrects that imbalance and is said to reward cleaner firms with a lower cost of capital while making dirtier ones pay more for investment. This is an attractive argument, though it depends on the numbers being accurate enough for investors to act upon, which brings the discussion back to scope three.

The objections are not trivial. Preparing a full disclosure is expensive: emissions must be measured, checked by an accountant and, increasingly, audited. Business organisations representing smaller listed companies complain that the burden falls hardest on firms with the fewest staff and the least spare money, and that some will consider leaving public markets altogether. Environmental groups make a different objection. In their view, a company can publish a full account of its emissions while continuing to increase them, and be praised for transparency rather than criticised for pollution. Reporting on a problem, they argue, is easily mistaken for solving it.

Is there evidence that reporting reduces emissions? Some studies of Britain's requirement, introduced in 2013, have found that companies covered by it subsequently cut their emissions relative to comparable firms that were not. Such studies are difficult to interpret, however. A firm that begins measuring its energy use often discovers waste that it can remove at no cost, so the first reduction may reflect better housekeeping rather than a new strategy. And reported emissions are not the same as actual ones: where figures are estimated, an apparent fall may only mean that a different method was used.

Scope three creates problems of its own. Because most companies have only sketchy knowledge of their suppliers, the figures are calculated with averages for whole industries, and a supplier that improves its performance may not be able to prove it. Researchers who study supply chains warn of a further risk: a firm ordered to account for its suppliers' emissions may simply drop the dirtiest ones, which reduces its own reported total without reducing anything in the atmosphere, and may harm the very economies that can least afford it.

Politics adds a further layer of uncertainty. In the United States, a federal rule requiring large companies to disclose climate risks was adopted in 2024, immediately challenged in court and suspended before it took effect; several states responded by writing rules of their own. A regime that can be reversed after an election gives companies little reason to build the systems needed to measure emissions carefully. Meanwhile the international standards are not law: they take effect only where a government chooses to adopt them, so the level of detail demanded of a business still depends on where it is registered.

My own view is that mandatory reporting is justified, but that its supporters have promised more than it can deliver. Disclosure is a floor, not a ceiling: it gives investors and regulators the information they need, but it does not by itself change what a factory burns. Two reforms would strengthen it.

Standards should be harmonised across borders so that a figure means the same thing everywhere, and the requirement should be phased in gradually, with a lighter regime for smaller firms. Reporting will do its work only if it is joined to a price on carbon or to regulation that limits emissions directly. Transparency is a necessary condition of sensible climate policy, not a sufficient one.