My Science School

When construction began on the high Dam at Aswan, in southern Egypt, it was realized that the temples of Abu Simbel would be completely submerged as the waters to the Nile rose behind the dam to create a much needed reservoir.

       In 1959 Egypt and its southern neighbor Sudan appealed for help to the United Nations educational, scientific and cultural organization. The first archaeological surveys began in 1960 and U.N.E.S.C.O’s response grew into what was to become the biggest archaeological rescue operation in history.

      Abu Simbel consists of three temples of Rameses II built more than 3,000 years ago. The most important and impressive temple included four gigantic seated statues of the king, each 65 feet high. By 1968 these four enormous monuments to Rameses had been cut out of the rock and reconstructed, exactly as they were, high up on a cliff.

      Six more great statues of Rameses and his queen (about 30 feet high) were also excavated and moved to a dry sanctuary above the old river bed, along with everything else that could be salvaged.

The name anticyclone was first introduced by sir Francis Galton, the English meteorologist, in 1861 to describe weather conditions opposite to those of a cyclone. Anticyclones are characterized by fine weather and weak winds.

      In weather maps and climatic chances anticyclones appear as a region in which the pressure is higher than n its surroundings. So when the weather forecaster starts to talk about anticyclones you can be prepared for the weather to remain stable for some time, usually sunny and with occasional light rain.

      In a cyclone or low-pressure area the winds circulate anticlockwise in the northern hemisphere and clockwise in the southern hemisphere. Cyclones are usually areas of strong, violent winds and indicate bad weather.

The Sargasso Sea is in the Atlantic Ocean south of the Bermudas and several hundred miles east of the American mainland. It is famous for its seaweed and as a spawning ground for eels.

     When these eels are eight or more years old and spawning time is due, they leave the pond or stream where they have been living and make their way, over land if necessary, to the sea.

      When they reach the area known as the Sargasso, the females lay their millions of eggs at a depth of 1,500 feet and the males fertilize them. The baby eels hatch out after a few days and float to the surface. Vast masses of seaweed lie on the surface of the Sargasso.

      Carried along by winds and ocean currents from the Gulf of Mexico and Caribbean Sea, this floating seaweed is concentrated into an area many thousands of square miles in extent. There it gives refuge to myriads of sea creatures, such as fish, sea-worms, mollusks, and crabs and jellyfish. Sea birds find it useful as a resting place.

      This floating “island” may have given rise to the famous legend in ancient times of the lost land of Atlantis. Christopher Columbus recorded taking two weeks to sail through it in 1492.

        But what happens to the baby eels? Drifting at first, they eventually make their way to the ponds and streams of their parents. The American eels go to America and the European eels to Europe. The old eels do not return but die after spawning.

      The Sargasso Sea is the subject of many legends. Ships are said to have vanished in it, but there is no truth in the legend that associates it with the lost land of Atlantis.

The smallest count in the world is the Vatican City. The Vatican is an independent and sovereign state within the boundaries of Rome in Italy.

   Although the Vatican has always been the spiritual and administrative centre of the Roman Catholic Church, it did not become an independent state until 1929.

    The city state has a daily news paper, a railway station, and its own bank. It has an area of 0.17 square miles and a population of about 1,000.

     There are no frontier formalities for those entering Vatican City where millions yearly visit St Peter’s and the exhibition galleries.

    The chief treasures to be seen are the Michelangelo frescoes in the Sistine Chapel, paintings by Raphael, Fra Angelico and Caravaggio, the frescoes of Pinturicchio and the codex Vaticanus of the Greek Bible.

      Pumice stone is formed when molten volcanic glass, ejected from beneath the earth’s crust, cools so rapidly that there is no time for it to crystallize.

     After the pumice has solidified, the gases inside are suddenly released and the stone swells up into its characteristics light and airy form. If the substance had cooled under greater pressure it would have turned into solid glass.

     The stones have long been used for cleaning and polishing. Since the Second World War it has been employed widely in railroad building, masonry and insulation. Good pumice is found in Iceland, the Canaries, New Zealand, Greece, the pacific coast of the United States and many other areas with a volcanic background.

    A river always takes the easiest course through channels and soft ground to the sea, flowing swiftly down mountain sides but much more slowly on the level plains.

     On the plain the river takes advantage of every difference in gradient. This winding course is accentuated by the process of silting and erosion. As a river flows round a curve, the water on the outer bend moves more swiftly to cover the greater distance in the same time as the water flowing past the inner bend.

     The more rapidly moving water will tend to wear away the banks of the channel, while the slower movement of the water on the inside wall will allow silting to take place. When the curve becomes more pronounced it is known as a “meander”. Notable examples of meanders are to be found in the Wye in England, and the Meuse in France.

      Sometimes the river erodes the bank so fiercely that a new channel is formed, leaving as island of earth in the middle of the stream.

        A party of Spanish explorers led by Francisco de Orellana became in 1541 the first Europeans to travel the length of the Amazon River. The journey followed a meeting in Peru between Orellana and Gonzalo Pizarro, half-brother of Francisco Pizarro, the Spanish conqueror. Gonzalo Pizarro, who was governor of Quito, was about to lead an expedition into the unexplored eastern region. Ore llano was appointed his lieutenant and sent ahead of the main party by boat with 50 men to search for food. When he reached the junction of the Napo and Maranon rivers, his desire to explore on his own account led him to desert Pizarro’s expedition. He pressed on with his party and followed the huge river system down to the Atlantic Ocean, which he reached on August 26, 1542.

          It is said that he named the river after a tribe of fighting women whom he encountered near the mouth of the tributary Trombetas and who reminded him of the battling Amazons of Greek mythology.

       The Amazon is the greatest river in South America, flowing from its source in the glacier-fed lakes of central Peru for 4,000 miles across Peru and Brazil to enter the Atlantic at the equator.

          The Gulf Stream is in the Atlantic. It is a warm ocean current which flows steadily from the Gulf of Mexico north-eastwards. One branch reaches the Canary Islands, turns southwards and moves back across the south Atlantic. The other branch flows past the western coasts of northern Europe.

           This current, which is like a river in the sea, is 50 miles wide at its narrowest and nearly 2,000 feet deep. It sweeps along with it many forms of warm water life from the tropics, but these die before they reach the European coasts where the warm water mixes with cold water moving down from the Arctic.

      The Gulf Stream has a great effect on the weather of Britain and Norway. The prevailing south-westerly winds are warmed by it and collect moisture which turns into rain. In winter the warm water keeps open the cold northern ports, such as Hammerfest, in Norway, and Murmansk, in the Soviet Union, while harbours in the Baltic, many miles farther south, are blocked with ice. In summer it causes bright flowers to bloom on the West coast of Spitzbergen 500 miles north of Norway. In contrast, the east coast, cooled by arctic water, is bleak and colorless.

       In 1912 the United States congress was asked for money to build a jetty which, it was thought, would divert the Gulf Stream and make it flow up the east coast of the United States. Although this scheme was unlikely to be successful, it was just as well for Britain and Norway that it was never tried. Without the Gulf Stream, Britain’s winters would be very much longer and colder, and Norway’s harbours, which are vital to the country, would be frozen over for many months.

 

 

           Some plants capture insects and other tiny animals and use them as food. They do not devour their prey by chewing but decompose them in a mixture of enzymes. The pitcher plant attracts an insect to its large showy leaf by means of sweet-smelling nectar. The leaf has a treacherous lip which precipitates the unwary victim into a deep hollow pitcher full of digestive “broth”, which soon decomposes its body. Other plants, like the Venus’s flytrap, snap their leaves shut on their prey as it prowls about the trigger hairs glistening with drops of nectar. The sundews secrete a sticky fluid.

      Leeches, which are rather slimy worms and vary in length from an inch to several inches, have two suckers, a big one at the rear and a smaller one at the mouth end. They have powerful muscles which enable them to expand and contract their bodies.

      This makes them excellent swimmers. They can also use their suckers to crawl on the land in tropical Asia, the island of the Pacific and the Indian Ocean, there is a particularly vicious and dreaded species of land leech which enters the breathing passages of animals, gorges on the animal’s blood and swells so that it cannot escape.

     Aquatic or water leeches cling to fishes, turtles and shell fish. Some leeches feed on earthworms and frogs’ eggs. Others live on the larvae of insects and even on the microscopic life on the floor of the pond.

     Leeches have been used in medicine from early times until quite recently to draw blood from a patient.

A loofah is a fibrous, cylinder-shaped vegetable product often used in bathrooms as a kind of rough sponge or gentle brush. It is the dries interior of the fruit of a plant known to botanists as Luffa aegyptiaca. Less dignified, though more descriptive, names for this tropical climbing or trailing herb are dishcloth gourd and vegetable gourd.

     The Luffa belongs to the great gourd family of plants, and its 800 relations include the cucumber, the melon and the pumpkin. In spite of having an unpleasant smell, the Luffa is cultivated in Egypt (hence the second part of its Latin name) and in Arabia, India and china. The yellow-flowered climbers can sometimes be seen adorning the trunks of palm trees. Besides being used to make loofahs, the luffa’s fruit is eaten in curry.

     The development of man-made materials has led to a decline in the loofah’s popularity, but many people still use its slightly abrasive qualities to stimulate the skin.

      The breadfruit tree is found in the South Pacific Islands and, to a lesser, degree, in other parts of the tropics. It is an extremely handsome tree, growing up to 60 feet high. The oval leaves are a pleasant, glossy green and quite large.

      There are two distinct forms of breadfruit, one seedless and the other containing many seeds which, when boiled or roasted, taste much like chestnuts.

   The breadfruit, which contains a considerable amount of starch, is not really a fruit in the popular sense and is rarely eaten raw. It can be boiled or baked, served with salt, butter or syrup, and even sliced and fried like potatoes.

     Yews have long been associated with religious worship. So it is likely that churches were originally built near the sacred trees rather than the other way round.

     These trees live longer than any other species in Europe and can grow to an enormous size. Many are thought to be well over 1,000years old. Yews were revered by the druids of ancient Britain, France and Irelands and no doubt early Christian missionaries preached in the shelter of the trees before their first churches were built. Hywel Dda Howell the Good a Welsh king, who reigned in the 10th century, set a special value on “consecrated yews”.

   Some yews are even older than the ancient churches beside them, suggesting that the church was built on a spot already devoted to worship. The association continued, and it became traditional for yews to be planted in church yards.

    Also the great age to which yews live caused them to be regarded as a symbol of immortality and, therefore, associated with death, as man only becomes immortal after he dies.

A salamander is amphibian-an animal that lives both on land and in the water. It is a lizard like member of a group of back-boned creatures between fish and reptiles. This class includes frogs and toads. Like fish and reptiles, the salamander is cold-blooded.

      It was anciently believed that the first salamander was born out of the court of a fire and that the so called fire salamanders were unaffected by heart. In fact, the salamander is active usually only in the cool of the night, when it hunts worms, slugs and insects.

     The salamander, which grows up to about 11 inches long, is attacked by few enemies, as its skin glands are poisonous. But the European water snake is not affected by the venom and frequently asked the salamander its prey.

   

 

    During winter flies will hibernate sometimes in large groups, in any available dry and warm space such as an attic.

     The reason there are so few houseflies in winter is that their eggs will hatch only at temperatures between 240 centigrade and 350 centigrade (750 Fahrenheit and 950 Fahrenheit). Meanwhile their numbers steadily diminish owing to insecticides and natural causes. This is a good thing since flies often carry diseases.