My Science School

       Some countries still have colonies and dependencies because these are usually small territories, often with few inhabitants, which do not have the capacity to carry out all those aspects of administration and government necessary to an independent state.

       Nowadays, the possession of colonies is an embarrassment rather than an advantage to the country having them, and few are retained against the wishes of their people. Before the great decolonizing years which followed the Second World War, having colonies seemed a natural part of being a great power.

        France had many overseas territories such as Algeria, French Morocco and those of French West Africa, but all of these are now self-governing republics. Italy had Eritrea, now federated with Ethiopia, and Italian Somaliland, now the Somali Democratic Republic. Holland’s Old Dutch East Indies is mostly the present-day Republic of Indonesia.

          As in the case of the British Empire the breaking up of these empire left many small territories who were not big enough for independence or who preferred to wait. These saw advantages in remaining under the protective umbrella of a greater power.

        Such protection means that defense, external affairs, internal security, and the safeguarding of the terms and conditions of public officers are the responsibility of the colonizing power through its appointed governor.

        In some cases the governor is also responsible for the financial and economic stability of the territory. But internal affairs are normally in the hands of the locals.

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               Clouds vary in shape according to their height and temperature, and they contain minute drops of water or ice particles or a combination of both. And, of course, their forma­tion is greatly affected by wind changes.

               There are basically three groups of clouds: high clouds between 17,000 and, 45,000 feet (cirrus, cirro-cumulus' and cirro-stratus); middle clouds between 7,000 and 23,000 feet (alto-cumulus, alto­stratus and nimbo-stratus); and low clouds up to 7,000 feet (strato­cumulus, stratus, cumulus and cumulo-nimbus. Their height and temperature decide how much pressure is exerted on them by the atmosphere.

               Finally, the shapes of clouds differ according to the time of day. Towards evening Clouds tend to thin out, rise a little and flatten out.

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               Sheet lightning usually occurs during a storm as the result of a discharge of excess electricity within a single thundercloud. The outline is obscured and the result is a diffused light spread over a large area of the sky in contrast to the vivid spiral or ribbon-like flashes of chain, forked or zigzag lightning. The most favorable conditions for sheet lightning are provided when the electric field is equal throughout the area. Unlike other forms of lightning it does not reach the ground and the channel cannot be distinguished.

               What is often referred to as sheet lightning is merely the light­ing up of the sky by flashes occurring beyond the horizon.

               All lightning is the natural dis­charge of large accumulations of electric charges in the atmosphere. It may take place between neighboring clouds or between cloud and earth. Just before the dis­charge the cloud's electric poten­tial is often built up by the action of falling raindrops or other natural processes.

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          Constantinople, now the Turkish city of Istanbul, was called after the Roman emperor Constantine the Great. The name means city of, Constantine. He was born at Nish in what is now Yugoslavia about A.D. 280 and was educated at the court of Galerius, the ruler of the Eastern Homan Empire. In A. D. 306 he was proclaimed Caesar:

          At this time the Roman Empire was governed by four rulers, but the system did not work well, and Constantine decided there should be only one ruler-himself. He became a Christian as the result of visions he had seen promising him victory over his rivals if he em­braced the new faith. Rome fell to his troops and in A.D. 323 the last of the independent rulers was defeated, leaving Constantine in command of the whole empire.

          He changed the capital from Rome to the ancient city of Byzantium, on the shores of the Bosporus. He enlarged the city, renamed it Constantinople and enriched it with many churches and palaces.

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        The Date Line (usually called the International Date Line), is a north-south line through the Paci­fic Ocean where, according to international agreement, the date changes. East of  the Line it is one day earlier than it is to the west.

        The line is necessary because the earth is divided, longitudinally, into 24 one-hour time zones (15° longitude each) which make one full day on the earth. Since the earth rotates eastwards, the time on the clock progresses westward, round the world. Thus, 12 o'clock noon arrives in London (0° longitude) five hours before it does in Washington, D.C. (75° west of London) and eight hours before it does at San Francisco (120° west of London). When it is noon in London it is midnight 180° to the west.

           On either side of the 180th meridian the time is the same. But you would lose a day if you crossed it from the east and gain one if you travelled across it from the west.

           The Date Line has some varia­tions from the 180th meridian to allow for land areas or islands. The line bulges eastwards through Bering Strait to Take in eastern Siberia and then westward to include the Aleutian Islands with Alaska. South of the equator bulges east again to allow various island groups to have the same day as New Zealand.

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            Icebergs are huge masses of ice which have broken away from glaciers in the Arctic and Antarctic regions. They gradually melt away as the upper part is warmed by the sun and the lower part by the warmer waters into which they drift.

            An iceberg may be as much as 250 feet high, although only one­ ninth is above the surface of the sea. It can be a hazard to shipping.

            The worst disaster was to a British passenger liner, the Titanic. This fine ship was thought to be unsinkable, because she had a double skin and 15 watertight compartments. In April, 1912, the liner struck an iceberg in the North Atlantic. Despite her double skin and watertight compartments she was holed and quickly sank. Of the 2,207 people on board, more than 1,500 were drowned.

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          A legend says the coffee plant first grew in Kaffa, a province in south Ethiopia, where it was discovered by a goatherd called Kaldi about the year 850. Kaldi’s goats were reported to have skipped and pranced in a strange manner after feeding on an evergreen plant. The goatherd, so the story goes, tried some of the berries himself and excitedly dashed to the nearest town to tell of his find, which was called coffee after the name of the province.

          Another theory is that the word coffee is probably derived from the Arabic qahwah. Certainly coffee was introduced info Europe from Arabia during the 16th and 17th Centuries. The first license to sell coffee in the United States was issued to Dorothy Jones of Boston in 1670. The coffee houses of this time became famous meeting places for discussion.

          As the drinking of coffee be­came more popular, its production spread to Java, Haiti, Dutch Guiana, Brazil, Cuba, Jamaica, Puerto Rico, Costa Rica, Vene­zuela, Mexico, Colombia, the Hawaiian Islands and, in this century, Africa.

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               People stop growing when their bones do, and that is usually between 15 and 25 years of age.

               Bones are made up of living tissue, composed of special cells which secrete round themselves material rich in calcium salts and as hard as marble. The formation of bone (ossification) is a complex process which usually begins in cartilage (gristle).

               In a child the bone begins to form in the middle of the cartilage and spreads towards both ends, turning it all to bone with the exception of the tips. From these points the bone grows in length and so does the child. When the growing period is over the tips of the bones close by joining the main shaft of the bone.

              Bones vary greatly in shape and size. Long ones act as levers. Flat ones are centers for muscle action. But each has a cavity containing bone marrow. Around this the bony substance is spongy in texture, becoming hard nearer the surface where the calcium is densest. On the surface of the bone is a special layer of fibrous tissue (the periosteum) which is rich in bone-building cells.

            Surtsey is a volcanic island a few miles south-west of the West man Islands which are situated off the south coast of Iceland. The island appeared as a result of a volcanic activity on November 15, 1963. The Icelanders took the infant island into their care because it appeared in their territorial  waters.

            They called the volcanic vent Surtur, and the island Surtsey (island of Surtur): In Old Icelandic mythology Surtur was a giant who brought destructive fire from the south as a weapon in his fight with Frey, the god of fertility.

            During its early life there was doubt about the island's chance of survival, and many thought it might disappear. A similar one did vanish in 1783 after erupting from sea 65 miles south-west of Reykjavik, the Icelandic capital. Survival and long life were assured when re­peated outpourings of thin flowing lava followed the first violent eruptions. The lava capped the volcano with a gently sloping regular dome which acted as a protective shield.

            The arrival of Surtsey was no real surprise. For the 10,000-mile Mid-Atlantic Ridge, of which Ice­land forms the largest above-sea land mass, had been active along its length for some years up to 1963, although since then things seem to have settled down, al­though further activity is always possible. The neighbouring West man Islands were produced by volcanic activity 8,000 years ago.

          Twilight is the faint light which appears a little before sunrise and again after sunset before it gets really dark.

          On the moon there is no twilight. Darkness comes suddenly as soon as direct sunlight ceases to reach the moon's surface. This does not happen on earth because of the halo of air, called the atmosphere, which surrounds it When the sun goes below the horizon, its light leaves the earth but is' reflected downward from the upper atmos­phere.

          Poets and writers have written of the evening twilight or “the gloaming”, as it is called in Scot­land - as an enchanted time. Per­haps one reason is that familiar objects become distorted in the half-light and we imagine we are seeing things that are not really there.

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               A river winding its way down to the sea, from its mountain source, will inevitably choose the lowest land through which to flow. By the time the river approaches the sea the speed at which it is travelling will have decreased considerably, thus allowing the water to drop its load of sediment and other solids.

               These solid particles (alluvium), therefore, form the land pockets which are characteristics of the various branches of a river delta. Owing to the slow pace of a river at this stage, it will wind its -way round any elevated land points rather than go over them.

               Deltas are most likely to form where the sea, into which the river flows, is particularly calm for most of the year. Notable deltas in the world include the Mississippi (the largest) the Ganges, end the Nile. A delta is so called because it is the name of the fourth letter of the Greek alphabet whose shape it resembles.

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            A geyser occurs when a hot spring erupts, hurling a column of water and steam high into the air. These springs are situated in regions which were formerly volcanic and which have retained considerable heat near the surface.

            They usually have craters with well-like shafts penetrating into the earth. The water which gathers deep down in these shafts becomes heated until the lower part is changed into steam, the pressure of the steam steadily mounts to a point when it suddenly hurls the water above it into the air, sometimes to a height of over 100 feet.

            The chief geyser districts are in Iceland (home of the Great Gey­ser), in the Yellowstone National Park, Wyoming, United States, and in New Zealand. For four years Waimangu in New Zealand, the greatest of all geysers, was capable of spouting jets up to 1,500 feet.

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           The Everglades are in Southern Florida in the United States. The peninsula of Florida, low lying and with a climate ranging from warm temperate to subtropical, stretches out from the American mainland towards Cuba. In the, south of Florida lies the state's biggest stretch of inland water, Lake Okeechobee. Spreading south from this is the huge wet prairie called the Everglades which, after 100 miles, gives way to the man­grove forests fringing the peninsula's broad tip.        

          The Everglades have a slope to the south of only two inches to the mile and, along the eastern side of the great prairie; there is a river with an almost imperceptible flow. This river, which is only a few inches deep and 50 miles Wide, moves slowly towards the south. Along the west side tall cypresses, hundreds of years old stand in the Big Cypress Swamp. The whole area is waterlogged, for beneath the peat beds there is a porous rock which soaks up water like a sponge. All this freshwater-soaked land keeps back the salt water of the Atlantic Ocean, and the excess of water flows into the sea,

            Grasses grow in the shallow, slow-moving river. Tall cypress trees flourish in the swamps. The area is rich in vegetation and wild life, a primitive world, thousands of years old, continues into the present and the Americans sought to preserve this by creating the Everglades National Park. But in spite of these efforts, civilization is destroying’ this Primitive world. Agricultural land is being re­claimed by draining the swamps. Water is being taken from Lake Okeechobee and diverted from the river to quench the thirst of the Atlantic seaboard cities of Palm Beach and Miami. On the surface, the peaty soil dries out and be­comes easily ignited tinder. Care­lessly thrown cigarette ends create hundreds of fires.

            As the swamps dry out and become barren, Nature’s balance is destroyed and the wild life is threatened with extinction. The Everglades may well be doomed.

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            Since the 1940s scientists have discovered techniques by which. Several weather conditions can be controlled. For example, it is pos­sible' to prevent lightning by using an electrical earth to diffuse the electrical content of a cloud. The American scientist V. J. Schaefer has shown .that it is feasible to produce greater concentrations of ice in clouds than occur under normal conditions.

            Weather experts already are taking advantage of these dis­coveries to increase snowfall on mountains for winter sports, to prevent damaging hailstones and to moderate, or even prevent, the development of dangerous storms. Scientists are now able, in some cases, to make a cloud burst to produce rainfall over parched areas.

            These local efforts may lead the way to large-scale weather con­trol. But before then scientists may' have to learn to cope with the damaging effect of air pollu­tion on weather conditions.

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          Granite is a very hard kind of rock made up of small pieces of mica, quartz and felspar and sometimes other rocks as well. There are many kinds of granite and they may be pink, grey or white. But the most striking thing about granite is that the pieces of rock from which it is made are all crystalline and shine like a wall of snowflakes.

          One city in Scotlandcalled Aberdeen is known as the silver city, because of the way the granite from which it is built shines in the sun.

          This rock is widely used for building, and is especially useful for large engineering jobs such as the making of breakwaters. Not only does it stand up well to the weather but, unlike many other rocks, it can be quarried in huge slabs. It is also used as an orna­mental stone after being polished to a smooth surface.

          Granite is found all over the world and forms part of most of the world's mountain ranges. There is a city in the State of Illinois called Granite City, while the Mountain State of New Hampshire on the eastern side of the United States is called the Granite State on account of the granite quarries there.

          You may have heard the expression “granite features” used to describe persons. This means that they have cold, hard faces, like a granite rock.

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