My Science School

The animals of Africa, many of them belonging to species which are now rare, today live under special protection from the danger of being hunted into extinction.

These animals live in national parks, huge areas reserved for them in central and eastern Africa. With the aid of wildlife Fund, these parks have become great tourist attractions. Every year thousands of people come from all over the world to see the giraffes, elephants, lions, gazelles, rhinoceroses, hippopotamuses and reptiles which live in freedom in these reserves.

There are good tracks and smooth roads and visitors can drive for hundreds of kilometres through these national parks. Some of Africa’s most important reserves are in Kenya and Tanzania. The Serengeti National Part in northern Tanzania covers an area of 15,000 square kilometres and extends from Lake Victoria to Mount Kilimanjaro. It has the finest collection of plains animals in Africa and is especially famous for its lions.

 

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The fame of Venice and its incomparable natural and artistic beauties was confirmed when a world-wide fund was opened to save its treasures. The enormous sums collected show the love felt in every part of the world for this Italian city, set on the water.

Venice is built on about 115 islands in the Adriatic Sea, 4 kilometres east of the mainland to which it is connected by road and rail. The city is interested by canals, the chief of which is the Grant Canal, and has nearly 400 bridges.

In addition to its canals and bridges, Venice is renowned for its churches and palaces. The most famous of these are St. Mark’s Cathedral with its tall campanile beside it built at one end of the Piazza San Marco, and the Doges Palace.

In the course of the centuries, innumerable artists have been inspired by Venice and in return they have left the results of their creative genius.

 

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Covering an area of less than half a square kilometre the Vatican City is the smallest state in the world.

Approximately half of its territory is occupied by famous constructions: the Basilica of St Peter standing at the head of a large square which is encompassed by Bernini’s magnificent colonnade; the Vatican palaces, the residence of the Pope; the Vatican museums, rich in works of art; and the Sistine Chapel. In the remaining area are garden, ships, squares, a railway station and an astronomical observatory.

 

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The tulip is undoubtedly one of the best known and most popular flowers in the world. Its vivid colours and the simple lines make it a small masterpiece, much prized in both gardens and homes.

The ancient origin of the tulip is unknown, but we have much information on its introduction into Europe. It was the TURKS who brought this flower to the West some 400 years ago. The name tulip means ‘turban’ which the flower is thought to resemble.

There is probably no other flower which has been given such an enthusiastic welcome or spread so quickly throughout Europe. Within the space of a few years, the craze for tulips grew into ‘Tulipomania’, reaching its height in Holland.

Certain rare varieties fetched astronomical prices: by 1610 some tulip bulbs were worth as much as an ale-house or a mill. One bulb was paid for with a new carriage, complete with two horses, another was exchanged for 12 acres of land. Materials and lace were decorated with designs of tulips. This craze lasted for almost half a century.

 

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Beneath the city of Wieliczka in Poland lies one of the most extraordinary sights in the world; a subterranean town made of salt.

This town is in the heart of a salt mine which goes down to over 300 metres below ground and has more than 112 kilometres of tunnels. All the elements that make up the town are built from salt, that is from sodium chloride in a crystalline state, which has a consistency similar to that of porous stone. Everything is made of rock-salt, from the pillars to the lamp-posts, from the streets to the bridges. There is everything here that you would find in any small town: a church decorated with basreliefs, a railway station, a throneroom, a ballroom, small lakes, wide specious streets. All that is the work of the miners who through decades of patient labour succeeded in completing labour succeeded in completing this colossal task.

Although there are other towns made of salt in both Poland and Austria, Wieliczka is the most complete and most perfect of them all. The salt mines there have been worked for over nine centuries.

 

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One of the most active volcanic areas in the world is Iceland: in addition to craters which have been dormant since time memorial, the island has some thirty active volcanoes.

Iceland possesses other volcanic features, such as thermal springs and solfatara (which emit sulphur and water vapour gases); the most notable are the geysers which are jets of water at a high temperature.

The Icelanders have taken advantage of these hot springs: they have directed them into a system of pipes which heat homes, swimming pools and greenhouses. Since 1943 the whole city of Reykjavik has thus been able to solve its heating problems.

 

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The valley of the roses’ could be the title of a novel or a romantic film, one of many fantasies; instead it actually exists in Bulgaria.

It is a narrow valley (enclosed by two mountain chains and crossed by the Tundza, the principal tributary of the river Maritza) which at harvest time becomes a sea of roses, a unique spectacle. Until the height of summer every morning at the first signs of dawn the petal pickers fill their large sacks and hurry to deliver their product to be processed before the petals lose their fragrance.

Rose essence, known and appreciated in all parts of the world, is extracted from the petals.

 

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Looking at a map, Finland seems like a piece of lace, a tunnel riddled with an infinite number of very characteristic lakes.

Finland has, quite rightly, been called the land of lakes: in fact, from the smallest, which is virtually a puddle, to the largest, the Saimma situated in the south, it has tens of thousands of lakes which cover 9.4 percent of the country. This Lake District with its inland archipelagos has been less effected by outside influences than the coastal regions.

Someone once said that there are two dominant colours in Finland, blue and green; the blue of the lakes and the green of the forests. If we add to these colours the white of the snow that for a good part of the year covers Finnish territory, we have named the three national colours of Finland. The snow feeds innumerable rivers which often link the lakes.

One feature which may seem strange in country as flat as that in southern Finland is the way the lakes are on different levels. Sometimes characteristic waterfalls, which the Finns have used for the production of electric energy, are formed by a river flowing rapidly from one lake to another.

 

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Eskimos spend much of their time hunting seals. During the spring and summer they pursue the seals in their canoes, or kayaks, harpooning them in the open sea, but all sorts of cunning ruses are also used. The Eskimo disguises himself as a seal and lies motionless for hours waiting for one of the animals to come near him, or he will drag himself along like a seal to where a group of these animals are baesking in the Sun.

The most unusual methods of hunting are used in winter when seals spend most of their time under the ice-covered water of the sea. Every seven or nine minutes they must come to the surface to gulp down a new supply of air and for this purpose the seals open up holes in the ice as breathing places.

A skilful hunter first finds these breathing holes which are hidden under heaps of snow, and then waits motionless for hours until a passing seal decides to come up for air. When it does the Eskimos strikes with his harpoon.

The Eskimo uses every part of the seal: the skin, the fat, the meat and the bones. For example, the seal’s flippers with the bones removed make good water bottles. The Eskimo hangs these water bottles near his chest under his clothes when travelling so that the contents will not freeze hard.

The skin is often used for clothes, especially for the outer shoe or boot because sealskin does not spoil with dampness.

 

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The name ‘Eskimo’ comes from the language of the northern Red Indians and means ‘a person who eats raw meat’. It is an appropriate name because the Eskimos live mainly by hunting and fishing and in winter do not always cook the animals they catch.

This is because it is impossible to find any fuel for a fire in the icy waste that they inhabit. The only form of fire they have is produced by burning the oil of seals or whales in shallow, saucer-shaped lamps, made from pottery or stone. These lamps are used primarily to give light but the Eskimos can also boil their meat and fish over them. These foods are also frozen or dried.

There is another reason why the Eskimos sometimes eat raw meat: in this way they get the greatest possible nourishment. The Eskimos make up for the lack of vitamins from vegetables by eating the kidneys and liver of their prey raw. These organs have an abundant store of all the vitamins needed by the human body.

 

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The Aborigines of Australia believe in the existence of a life force they call kuran which is force varies in the different creatures which have it: the Aborigines believe, for example, that it is stronger in a man than in a woman, in an emu than in a wild turkey, that it is the same intensity in plants and weak in more simple forms of life. They believe that the life-force is at its most powerful in the medicine man or witch doctor, the ‘clever fellow’.

The life –force does not cease to exist when an individual dies. In fact they believe that the force shoes itself at its strongest at such times almost as if it were expressing its dislike of being excluded from physical life. The Aborigines do not believe that death is caused by natural causes such as illness, old age and accidents; to them death is always the work of an unfriendly supernatural power.

As soon as a dead person has been buried the whole Aborigine village moves away from the grave so as not to be troubled by the kuran of the deceased. After about three months it is thought that the life force will vacate the old body and be reincarnated in another.

 

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Until July 1853 Japan had been a land closed to all contacts with the west. No ports were open to Western ships, missionaries who tried to convert the people to Christianity were killed and all forms of Western culture were banned. But time did not stand still outside Japan. The early steamships that sailed across the Pacific Ocean needed places where they could replenish their fuel supplies and Japan was the ideal place for this. Despite much pressure from Western countries, however, Japan still remained closed to all their shipping.

The United States government then decided to send a squadron of naval ships under the command of Commodore Matthew c. Perry. Perry was told to persuade the Japanese to sign a treaty opening up some Japanese ports to Western ships. With two frigates and two sailing vessels he entered the fortified harbour of Urage on 8 July 1853. He refused to obey Japanese borders to leave and demanded that a suitable person be sent to receive the documents he had brought. The Japanese finally complied. Perry made a great impression on the Japanese dignitaries by his firm and dignified bearing. He returned with a larger force the following year and on 31 March 18564 the first treaty between the United States and Japan was signed.

By this treaty shipwrecked seamen were promised better treatment and American ships were able to obtain fuel and supplies at two Japanese ports. Japan’s traditional policy of isolation was broken and from that moment it established contact with the west. It was destined to become the leading country in the Far East and one of the world’s great powers. Only some fifty years later it subjected the Russian fleet to a crushing defeat.

 

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The cutting and polishing of diamonds are very delicate many varieties of glass beads.

Today we know that Zimbabwe was inhabited around 1000 B.C. and was only one of about 2000 such centres scattered through the country called Zimbabwe.

All gems are cut and polished by progressive abrasion using finer and finer grits of harder substances. Diamond, the hardest naturally occurring substance, has a Mohs hardness of 10 and is used as an abrasive to cut and polish a wide variety of materials, including diamond itself. Silicon carbide, a manmade compound of silicon and carbon with a Mohs hardness of 9.5, is also widely used for cutting softer gemstones. Other compounds, such as cerium oxide, tin oxide, chromium oxide, and aluminum oxide, are frequently used in polishing gemstones.

 

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It was already known in the last century that when the barometer showed a low air pressure bad weather could be expected and when the arrow pointed to a high pressure good weather was on the way. When all the air pressures of a region are known a map can be drawn up to show them. On these maps are drawn lines to join places which have the same air pressure: these lines are called isobars. When all these lines are drawn they reveal various systems of air pressures.

The anticyclones are areas of high pressure which usually bring good weather. Cyclones, or depressions, are low-pressure areas and usually bring rainy or stormy weather. Today meteorologists use equipment of great accuracy to probe the atmosphere around with a precision that would have seemed unbelievable not many years ago.

 

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When rainwater which contains a certain amount of acid falls on limestone rocks, a strange process can take place. The limestone begins to break up and caverns, some of them enormous, start to form under the ground.

Such a terrain is known as karst. This term was first applied to the Carso, a limestone area along the Dalmation coast of Yugoslavia, but is now used to describe any area with these features.

Karst represents a limestone rock which is honeycombed with tunnels and caves through which the rainwater runs, seeking a way out. As the water moves along it wears away more and more of the surrounding rock to produce long tunnels which turn into underground rivers. These rivers eventually reach the sea after appearing at the surface in places.

Speleologists have tried to follow the course of some underground rivers but many passages are too narrow for a man to get through.

One way of following their course is to place dye in their waters whenever they appear at the surface. They can then be recognized when they break through again.

 

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