Reading Test 06
The History of pencil
A.
Lightning struck first in the history of pencils. In 1564, during a thunderstorm in Borrowdale, England, graphite was discovered when lightning struck a nearby tree. The black substance found at the base of the unfortunate tree was determined to be something other than wood ash by the locals. Because of how pliable it was, it was easily marked. Since chemistry was still in its infancy at the time, it was mistaken for lead because both are equally dark and heavy. The locals quickly found a practical application for it in marking their sheep with symbols of ownership and numerical value.
B.
Graphite mines have been found and developed in Britain more so than in any other country. However, a pencil wasn’t created until much later. Graphite needs protection because it is so soft. For stability, Italians first wrapped graphite sticks in string or sheepskin, creating the world’s first pencil. Next, in the 1560s, an Italian couple likely created the first plans for the modern, wood-encased carpentry pencil. The pencils they used were smaller and flatter than the standard variety. As part of their plan, they carved a hole in a juniper stick. Not long after that, in 1662, Germans figured out how to make a better one by carving a piece of wood in half, inserting a graphite stick, and gluing the two pieces together. This is the same basic process that is still used today. Artists from all over the known world became interested in these primitive pencils after hearing about their usefulness.
C.
The “lead” of a modern pencil is actually a mixture of finely ground graphite and clay powders, despite the fact that the graphite core is still referred to as lead. The amalgamation is crucial as the quantity of clay added to graphite depends on the intended pencil hardness. In addition to this, the amount of time spent on crushing the mixture determines the quality of the produced lead. The middle portion becomes more durable by the addition of excessive clay. The European system of grading is used for a large percentage of pencils worldwide and is universal in Europe. A pencil’s grade was indicated by a sequence of Hs or Bs, such as BB and BBB for progressively softer leads and HH and HHH for progressively harder ones; B stood for black and H for hard in this naming system. Then, the most common pencil for writing is an HB.
D.
In England, they kept using whole sawn graphite to make pencils. But with the mass production of pencils, they are getting drastically more popular in many countries with each passing decade. Graphite usage has been on the rise due to rising demand. China, India, Brazil, North Korea, and Canada are the top five exporters of natural graphite, with total global production in 2012 at 1,100,000 tonnes, according to the United States Geological Survey (USGS). When the government realized how valuable graphite was, they stepped in to take control of the mines and put guards in place. As molds for making cannonballs, it saw extensive use in the second half of the 16th century, during the reign of Elizabeth I. It was armed stagecoaches that carried graphite from Keswick to London. The stealing of “wad” or its receipt became a crime under an Act of Parliament passed in 1751. This crime carried a sentence of hard labour or exile.
E.
By spending $1000 the United States made a pencil to use in zero gravity conditions in the face of fiction. However, they did not use pencils in outer space before real zero gravity pencil was invented. Mechanical pencils were highly preferable over grease pencils which were more favourable to Russians but as they produced smudgy lines, mechanical pencils which produced fine lines were much clearer comparatively. The only detrimental part of such pencils was that they used to break frequently. That bit of graphite floating around the space capsule could get into someone’s eye, or even find its way into machinery or electronics or other problems. Americans stayed dependent on mechanical pencils for many years even though they invented zero gravity pencils.
F.
The prospects of pencils seemed bleak against the backcloth of the modernising world. In reality, it does not. The use of pencils is widespread and can be seen in classrooms, meeting rooms and art rooms for instance, etc. In the future, it will likely be used by a wide variety of people, including students for writing notes in textbooks, artists for sketching ideas, waiters and waitresses for writing orders on whiteboards, cosmetic artists for applying products to skin, and architects for drawing up plans. It appears that anything is possible.
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Worms put new life into derelict site
Poisoned soil at an old steelworks is being cleansed by thousands of worms, writes Mimi Chakraborty. Thousands of deep-burrowing earthworms are to help turn the long-derelict site of a steelworks into Woodland and a renewable energy park. As part of a pioneering low-cost plan to reclaim the site of the former Hallside steelworks at Cambuslang near Glasgow, worms are being used to accelerate the process of soil regeneration and to transform the land, over time, into an attractive and financially productive site. Hallside’s closure in 1979 put an end to more than 100 years of steel production. The surrounding land had become heavily compacted and was too contaminated with heavy metals such as chromium, cadmium and lead to support any kind of brick and mortar development.
The site’s 30 hectares were left abandoned until 1990, when a rescuer plan put together by local landscaping and earthmoving company, HL Banks, and the regional developer, Scottish Greenbelt, was approved by local authorities. Now the site has been covered by a two-metre layer of partially treated sewage material which has been mixed with colliery waste. This will be converted into usable soil by about 20,000 Lubricus terrestrialis (garden lobworms) and Aporrectodea longa (black-headed worms) that have been let loose on the site.
The specially raised hermaphrodites, which are self-impregnating, will spend the next five to ten years chewing their way through the topping layer to create a soil structure able to sustain long-term plant growth. Without them, the process could take up to 60 years. Researchers at Bell College of Technology in nearby Hamilton examined the use of earthworms in land regarding, and found that even in the hostile mixture of coal-tip waste and partially treated sewage, earthworms were able to speed up the process of soil recomposition. They selected different varieties of deeper-burrowing earthworm species, whose bulk feeding and casting actions, as well as their ability to improve the mineral content of soil, would increase the rate of reformulation much faster than the natural processes.
Sean Ince, of Bell’s department of biology, says, “The idea is that earthworms will contribute in a cumulative way to further soil binding, and that they will aerate and add nitrogen to the soil covering the Hallside site.” At the same time, Scottish Greenbelt has begun planting the area with 250,000 trees — including willow and alder — specially selected for their ability to grow on degraded land. These will have the dual function of extracting contaminants from the soil through their root systems, and being harvested for wood burning or chipboard manufacture. By using the cash raised from wood harvesting, David Craven, director of Scottish Greenbelt, says he expects Hallside to be self-financing. “The first tranche of trees was planted in April and they are now over six feet tall, despite dry weather through the summer,” he says. “The fields are being planted on a four-year rotation basis and will be used to help us meet our costs.”
Craven says the cost of land bioremediation — the labour-intensive process of removing soil or chemical and bacterial cleansing — could have been more than £30m. At Bell College, Ince says: “There’s a whole legacy of toxic soil contamination going back many years. There is physical degradation of the soil as well as contamination from metals, including lead, chromium and arsenic.” Sampling of the soil at regular intervals over the next few years will give an indication of the level of contaminants. Within less than 20 years the land could be re-integrated into the community. Hopes of a successful outcome at Hallside have paved the way for similar regeneration plans for the nearby Gartcosh steelworks and at Glengarnock in Ayrshire.
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The strange world of sight
Seeing is believing, it is said. But, asks Richard Gregory, could it be the other any round?
Two of the great British men of the 17th century, the philosopher John Locke and the physicist Isaac Newton, were both aware that objects are not coloured, and that against all appearances light is not coloured either. This is still not generally recognised even now, 400 years later, because it seems so implausible. Yet it tells us something very important – that perceptions are not identical with what we perceive, and may be very different.
The most accurate historical account of perception is that of the 19th-century German scientist Hermann von Helmholtz. However, it was ridiculed at the time. Von Helmholtz thought that perceptions are unconscious inferences we make based on a combination of clues provided by the eyes and other senses, and knowledge of the world. This idea of unconscious inference for perception preceded, by several years, the psychoanalyst Freud’s notion of the unconscious, which was also initially treated with derision because it undermined the notion of humans as pre-eminently rational beings who could be held responsible for their actions and awarded blame or praise accordingly.
Crucially, perception of the present depends on rich, though of course not always correct or appropriate, knowledge from the past. We interpret sense data (what we hear, touch, taste, see and smell) from the present according to what we already know. This raises the question: if we see the present through memory, why aren’t past and present confused? The pioneering Russian neurologist Alexander Luria described the case of Mr S, who had a remarkable memory, however, he was prone to just such confusions, for example mistaking seeing his clock for remembering it, and so failing to get up in the morning. This suggests that perhaps an important function of perception is to underline the present. Individual perceptions have a vividness that is rare for memories, which might be how we are able to separate them. Try this: look at something for a few seconds, and then shut your eyes and visualise it in memory. You will almost certainly find that the memory is pale by comparison with the perception. Perhaps this is why past and present are not normally confused. Luria’s Mr S had exceptionally vivid memories, and rich synaesthesia (experiencing perceptions from another sense as well as the one being stimulated, such as musical notes experienced as colours), which may be why he confused seeing with having seen.
The complexity of processes involved in how we see first impressed itself on me 45 years ago. With my colleagues Jean Wallace, I studied the rare case Sydney Bradford, a man who had been born blind but, through a corneal graft at the age 52, suddenly found himself able to see.
Although immediately after the operation he was able to ‘see’ but he could only see those things that he already knew about, having experienced them through touch. It was his touch memories that enabled him to preserve them with his eyes. When Bradford was first taken to the zoo, he proved utterly unable to see an elephant as he had no knowledge to make sense of his perceptions.
The more recent case in California of Mike May, who was also born blind, is similar. Since his operation, his sight has gradually improved as he learns to see, for example, by understanding how shadows represent depth and tell us about the shape of things. Some of the consequences of May’s new-found vision were less happy. He had been a champion blind skier, but following the operation, he would have to shut his eyes while skiing to block out what he now found was a terrifying sight. But acceptance of this intimate connection between memory and perception, even though it was first noticed in the 17th century, has been slow in brain science. Despite the fact that state-of-the-art brain imaging shows that perception animates parts of the brain associated with both present information and memory, most research on memory and perception is still undertaken as if these were separate processes. Seeing used to be thought of as taking place only in the eyes, and in quite specialised brain regions; but now it seems that half the brain is occupied with seeing, requiring a lot of energy. Perhaps this is why we shut our eyes for a rest.
It is not just extreme cases like Mike May, but also much more common errors of seeing – illusions – that can reveal the crucial role of memory in governing what we (think we) see. Perception depends on specific knowledge and probabilities. Our brains calculate the likelihood of what is out there, and when too far-fetched, perceptions are rejected.
A dramatic and discomforting example is looking at the two sides of a face-mask. From the front it is a convex shape with the nose sticking out. Then if the mask is rotated, the back of the mask will be seen as convex, though we know that it must be concave. It is almost, if not quite, impossible to sketch the back of a hollow mask to look as it is – hollow. Science often learns from what does not happen: people not seeing a hollow face as hollow is the most revealing experiment on perception. The unsettling truth from brain science is that even people with no visual impairment see what, at some level, they expect to see, and often miss things as they really are.
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