IELTS Academic Reading Practice Test 246

According to their own histories, the Mexica — the people later known as the Aztecs — reached the Valley of Mexico in the thirteenth century as a poor and unpopular group driven from place to place. Their patron god, Huitzilopochtli, had promised them a homeland, and their priests announced that the sign would be an eagle standing on a cactus. The bird was found on a small island in the shallow Lake Texcoco, and there, in the traditional date of 1325, the Mexica founded a settlement they called Tenochtitlan.

The site had little to recommend it. The island was low and marshy, with little fresh water, no building stone and hardly any level ground that could be farmed. What the lake did offer was food and transport: fish, waterfowl and reeds were plentiful, and canoes carried people and goods between the islands and the shore. In time the Mexica improved on nature. Around the island they piled soil dredged from the lake bed into raised fields called chinampas, separated by narrow canals, which were watered and enriched by the muddy lake water and could produce several crops a year.

For its first century Tenochtitlan was a subordinate place. Its people paid tribute to the rulers of Azcapotzalco, the dominant city on the western shore of the lake, and supplied them with soldiers. In the 1420s, however, the Mexica joined forces with the cities of Texcoco and Tlacopan, defeated Azcapotzalco and formed an alliance that historians call the Triple Alliance. Tenochtitlan soon became the leading partner in it, and the tribute of a growing empire — food, cloth, feathers, precious stones and labour — flowed into the island city.

Water was the city's greatest problem and its greatest engineering achievement. During the reign of Moctezuma I, in the middle of the fifteenth century, engineers built an aqueduct that brought spring water from Chapultepec, on the mainland, along a causeway and into the city. It had two channels, so that one could be cleaned while the other continued to flow. Because Lake Texcoco was salty, dikes were also thrown across it to keep the fresh water separate from the salt, protecting both the drinking supply and the chinampas. Causeways linked the island to the shore, with gaps bridged by removable wooden sections that could be taken up in times of trouble.

At the centre lay the sacred precinct, a walled enclosure of temples and priestly buildings dominated by the Templo Mayor, a stepped pyramid with two shrines at the top. One was dedicated to Huitzilopochtli, god of the sun and of war, and the other to Tlaloc, god of rain and water; the pairing expressed the two concerns on which the city depended. The pyramid was rebuilt and enlarged on several occasions, each version wrapped around the last, so that archaeologists excavating it have found a sequence of earlier structures inside the final one.

Beyond the precinct the city was laid out on a grid, its streets and canals running straight for long distances. It was divided into four quarters, each with its own temples and market. The Spaniards who entered the city in November 1519 recorded their astonishment at its size, its order and the number of its inhabitants. They had expected a settlement of mud and thatch and found a capital of stone and plaster. Canoes moved along the canals as carts did in European towns, carrying produce, fuel and building materials to the markets and workshops.

How many people lived there is disputed. Most estimates for 1519 fall between 150,000 and 250,000, which would have made Tenochtitlan one of the largest cities in the world. The figures, however, rest on fragmentary tribute records and on the impressions of the conquerors. Its market, held at Tlatelolco, was the commercial heart of the valley. According to Spanish accounts it sold goldwork, cotton cloth, cacao, pottery, turkeys and slaves, and it was supervised by officials who settled disputes and collected dues.

The arrival of Hernán Cortés in 1519 destroyed this world within two years. The Spaniards were welcomed into the city by Moctezuma II, but relations collapsed, and in 1520 Spanish soldiers attacked a religious festival, killing many of the nobility. The city rose against them and the Spaniards fled by night, losing hundreds of men. Moctezuma died during these months; the circumstances of his death remain disputed among historians, and the accounts of the Spanish and of their Mexican allies do not agree.

In May 1521 the Spaniards returned with a large force of Tlaxcalan allies and laid siege to the city, attacking across the lake in small warships built for the purpose. By then smallpox, brought by the Europeans, had swept through the population, killing many thousands and leaving the defence short of leaders. The siege cut off food and drinking water. Cuauhtémoc, the last ruler, was captured on 13 August 1521, and by then much of the city had been destroyed in the fighting.

The victors built Mexico City directly on the ruins, using the stone of the temples for churches and palaces. In the following centuries the lake was gradually drained to make room for the growing capital. Because the ground beneath the city is soft lake sediment, many buildings have sunk unevenly, and the remains of Tenochtitlan lie beneath busy streets. In 1978, however, workmen digging foundations for an electrical substation uncovered a huge carved stone disc, and the excavation that followed exposed the Templo Mayor in full, although parts of it had been glimpsed earlier in the century; its remains are now displayed beside the cathedral.

In June 1816 snow fell across parts of New England. In northern Vermont the ground was covered for a day or more, and farmers who had already planted their maize watched the seedlings blacken with frost. Cold spells returned in July and August. The growing season was so short that in much of the region the crop never ripened. The year was long remembered locally as 'eighteen hundred and froze to death', a phrase that captures how the weather was understood at the time: as extraordinary bad luck. No explanation for it was available.

Thousands of kilometres away the summer was also disastrous. Across western Europe it was cold and exceptionally wet. In France, Switzerland and the German states the grain harvest failed; in Ireland the potato crop suffered too, and famine and epidemic disease followed. Bread prices rose sharply, food riots broke out in several countries, and governments struggled to import grain. In New England, farming families who had lost their crops gave up and moved west to Ohio and Indiana. This migration is often said to have been hastened by the events of that year.

The culprit was Mount Tambora, on the island of Sumbawa in what is now Indonesia. Its eruption in April 1815 was the largest of the historical period. Explosions were heard more than two thousand kilometres away, and ash fell on neighbouring islands for days. For a time the area around the mountain was so dark that lamps had to be lit at midday. The summit collapsed, leaving a caldera several kilometres across. The eruption, and the hunger and disease that followed it, killed tens of thousands of people in the region, most of them not by lava or falling ash.

Tambora changed the world's weather through what it put into the upper atmosphere. The eruption injected enormous quantities of sulphur dioxide into the stratosphere, where the gas was gradually converted into tiny droplets of sulphuric acid. These droplets stayed aloft for two or three years, drifting around the globe, and reflected a proportion of incoming sunlight back into space before it could warm the surface. The result was a fall in average global temperature of perhaps half a degree Celsius. That is a small figure in itself, but one large enough to shift the margins of agriculture in a world with no artificial fertilisers, no refrigerated transport and little stored grain.

Reconstructing all this has required several kinds of evidence. Ice cores drilled in Greenland and Antarctica contain annual layers of snow, and within them a band of sulphate confirms the year and the scale of the eruption. Tree rings tell a similar story: in many parts of the northern hemisphere the ring laid down in 1816 is unusually narrow, and in some places it shows damage from frost. Documentary records — diaries, parish registers, ships' logs, the dates of harvests and of first frosts — supply the local detail that ice and wood cannot, and allow historians to compare one district with another. Ships' logs are particularly valuable because they record wind and weather at sea, where nobody lived to keep a diary.

The attribution, however, is less straightforward than it looks. Historians of Europe have pointed out that the years around 1816 were already difficult: the Napoleonic wars had disrupted trade and agriculture, demobilised soldiers had flooded the labour market, and grain reserves were low. Bad weather made a crisis worse; it did not create it. Nor does a volcanic explanation account for the fact that some regions suffered severely while others escaped. Local harvests depended on soil, altitude, the timing of rain and the ability of authorities to buy grain abroad. Some scholars have also questioned how far the eruption can be blamed for the disease that followed, since typhus and other infections spread through populations weakened by hunger but also by crowding and displacement.

The summer left marks on literature. Beside Lake Geneva a group of English writers and their friends, among them Lord Byron, Percy Bysshe Shelley, Mary Godwin (later Mary Shelley) and John Polidori, were kept indoors by rain and cold in June 1816. To pass the time Byron proposed that each of them should write a ghost story. Mary Shelley's contribution grew into Frankenstein, published two years later, and Polidori's into The Vampyre, which appeared in 1819. Some writers have since suggested that the strange, dim light of that year, produced by dust high in the atmosphere, coloured the way painters saw the sky, though such claims are hard to prove.

1816 is now a standard example in the argument that climate has shaped human history. It is a good one, because the chain of cause and effect runs from a measurable physical event to harvests, prices, riots, emigration and literature. Each link can be checked against independent records. But it is also a warning. Popular accounts often present the year as a single disaster visited on humanity by a volcano. The record, by contrast, shows a patchwork of local outcomes and a great deal of ordinary political and economic failure. Weather, in other words, does not simply write history; it presses on institutions that are already weak or strong.

Switch on a television in almost any country and, sooner or later, you will find a historian. A single figure, often filmed striding through a ruined abbey or standing on a battlefield at dusk, explains a war, a dynasty or a revolution directly to camera. Such programmes attract audiences that any academic monograph would envy, and they have turned a handful of presenters into public figures whose views on the past are sought by newspapers and broadcasters alike. The best of them are knowledgeable, careful and genuinely interested in communicating what they know. The worst are something else entirely.

The case in favour begins with access. Most people will never read a journal article, and many will never open a scholarly book, but millions will watch an hour-long film about the Tudors or the Romans. Museums and heritage sites commonly report a rise in visitors after a series has been shown, and publishers reissue titles to coincide with the programmes. Teachers in universities also notice that some of their students arrive because a programme caught their imagination at the age of twelve. None of this is trivial. A discipline that is funded, at least in part, by public money has an interest in being understood by the public that pays for it.

Against this, critics make two substantial objections. The first concerns narrative. Television cannot easily show a process that is slow, collective and disputed; it needs a story with recognisable characters, a turning point and an ending. Historical explanation rarely arrives in that shape. Once the material has been cut to fit, the accidents and alternatives that make the past interesting tend to disappear, and what remains is a morality play in which the outcome looks inevitable. A decision that hung on a message arriving a day late becomes, on screen, the product of a great man's resolve. The past is thereby tidied up, and tidying is not the same as explaining.

The second objection concerns authority. In a book, an argument is set out and can be checked: the reader sees the sources, notices what is missing and can disagree with a footnote. On screen the presenter's voice carries a weight that the evidence, being invisible, cannot support. Viewers come to trust a manner — the raised eyebrow, the significant pause in front of a ruined wall — and the presenter's reading of events acquires the status of fact. The researchers who spent months in an archive appear, if at all, in the closing credits. Reputations are made by airtime rather than by the quality of the scholarship behind it. A young historian may reasonably conclude that learning to perform is as useful as learning to read a tax roll.

There is also a bias in what gets filmed. Battlefields, costumes, palaces and machinery are photogenic; a series about medieval farming or the history of insurance is much harder to sell. The consequence is that viewers receive a diet heavy in kings, battles and scandals and light on the slower history of work, trade, taxation and ordinary life. The same bias operates inside the past itself: a programme finds it easier to show what can be reconstructed visually than what mattered most to the people who lived through it. Some of the most important work in the discipline is therefore almost unfilmable, and the public hears little about it.

Yet the defenders of the genre have a strong reply. Simplification is not the same as falsification, and every form of history has its conventions. The printed page has its own habits of selection and emphasis, and a lecture compresses a lifetime of reading into an hour. Popularisation has always been how scholarship travels — through pamphlets, exhibitions and paperback histories long before anyone owned a television. Nor is the alternative attractive. If serious historians withdraw from the screen, the airtime does not become empty. It is filled by programmes with less knowledge behind them, and increasingly by material online that has no research behind it at all. Better history on television, not less, is the reasonable demand.

So where does that leave my own view? Television has not corrupted the study of the past, but it has changed the terms on which the subject reaches the public, and some of those changes matter. The habit I would single out is the pretence of certainty. Good television wants closure: the mystery solved, the question answered, the credits rolling. Scholarship is the opposite, a long argument in which the honest answer is often that the evidence will not settle the matter. A programme that admits where the evidence runs out is more trustworthy, not less, and audiences are perfectly capable of following a sentence that begins 'historians disagree'. There is no need to pretend otherwise.

On balance, then, the camera has done the discipline more good than harm. It has taken the past to people who would not otherwise have met it, and it has paid for a good deal of research that would not otherwise have been done. What it has not always done is to tell the truth about how historical knowledge is made. That is a fault of programme-making, not of popularity, and it is a fault that could be corrected tomorrow by a presenter willing to say, on camera, that the question is still open. Whether broadcasters will welcome that is another matter; the pressures of the schedule are real.