What is laughing gas?

   Laughing gas is the popular name given to nitrous oxide after its remarkable physiological effects were discovered by Sir Humphry Davy in his 'Researches,' published in 1800. The effects are generally of a pleasurable kind and the person under the influence of the gas is more or less excited, dancing, singing, laughing or indulging in other violent motions. This by prolonged inhalation ceases and stupor and anaesthesia, or insensibility to pain, supervene. Hence the use of this gas in dental and surgical operations.

What is holography?

Holography
Have you ever seen an exhibit or a movie in which a three-dimensional fig¬ure seemed to appear front nowhere? The effect may seem like magic, but it is more likely that the image is a product of holography. Holography is a technology that uses lasers to make the three-dimensional image called a hologram.

Hologram Uses 

 Holograms have many applications. They are now used as special effects in movies and plays. Holograms may someday be used to produce three-dimensional television.
Because they are difficult to duplicate, holograms are used as security devices. For example, some credit-card companies now put holograms on their credit cards. The holograms help to prevent the forgery of credit cards.
Holograms can also be used as educational tools. For example, holograms can be used to display a three-dimensional image of internal body organs. Medical students can use the images as a model to study the human body.

What is Heraldry?

Heraldry, the art and science of genealogy and of armorial bearings. In military affairs, the herald was an officer sent as a messenger by a sovereign or a general to one in equal authority—a sort of mili¬tary ambassador. The costume of a her¬ald was emblazoned with the armorial bear¬ings of his master. None other might wear it. He was expected to conduct himself with dignity as befitted the representative of a sovereign. Whatever his message he must be allowed to depart in peace. In the medieval ages the herald was a man of char¬acter, an authority on all such questions as genealogy, rank, official precedence, courts of arms, emblems, flags, etc.
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Who was Sitting Bull?

  Sitting Bull (1837-90) was a Sioux Indian leader, born on Grand River, South Dakota. He was named Tatanka Yotanka (Ind.. "Sitting Bull") after scalping an enemy at the age of fourteen. During and after the Civil War he led the warlike members of his tribe in attacks on white settlements in the north-central Great Plains region. A U.S. force, commanded by General George A. Custer, was annihilated (June 25, 1876) by his warriors in the Battle of Little Big Horn. Sitting Bull then fled to Canada. Receiving a promise of amnesty in 1881, he returned to U.S. territory. He continued to be hostile toward the Whites and persuaded the Sioux not to sell their lands. The tense situation among the Sioux was aggravated by the Messiah craze, which promissed defeat of the white man. Considered the leading instigator of the impending rebellion. Sitting Bull was arrested on Dec. 15, 1890. He was shot and killed by his captors when his friends tried to rescue him.

The World of Plants

  Without plants there would be no other life on Earth. For only plants can make their own food using simple materials - carbon dioxide gas from the air and water and mineral salts from the ground. Animals cannot make their own food: they feed either upon plants or upon each other. Plants also provide shade and shelter: birds, insects and mammals make their homes in trees.
There are about 500,000 species of plants, and they are classified in a similar way to animals. Many species of plants share the same common names.

The Plant Kingdom

  There are several groups of simple plants: algae, which include seaweeds and the scum on ponds; fungi, such as toadstools; liverworts, and mosses. Then come the ferntype plants: ferns, clubmosses, and horsetails.
The next group of plants is called the gymnosperms, which means 'naked seeds'. They have their egg cells and pollen in cones, and include cycads, ginkgoes, and the familiar conifers. Finally come the flowering plants, known as the angiosperms, which means 'seeds in a case'.
All plants except the simplest work in the same way. A typical plant has a system of roots, which anchor it in the soil and also absorb water and minerals from the soil. The stem carries the water from the roots to the leaves. It also supports the leaves and raises them up to catch the light.
Trees, bushes and shrubs have woody stems. The wood in the middle of a tree trunk is very hard and no longer carries water, but it provides a strong support for the tree. The trunk grows a little thicker every year and you can tell the age of a tree stump by counting the number of growth rings across its trunk.

How animals are able to avoid poisonous plants

  Although the species of poisonous plants are comparatively few in number, the number of individuals is large. With so many poisonous plants occurring over a wide range, one might wonder how animal life has survived so well. The answer is that animals seem to be able, in some way that we do not understand, to avoid these dangerous forms of vegetation.
  It is an old belief that in the jungle, if a man eats only what he sees monkeys eat, he will run no risk from poisonous vegeta¬tion. Certainly, animals do seem to know instinctively which plants are safe for them to eat. As we have seen, they shun some plants because they give off an unpleasant odor. Even if poisonous plants do not give off any odor — or at least an odor that is perceptible to human beings — animals seem able to avoid them. Certain grazing animals also keep away from various mosses and ferns which, as far as we know, are not poisonous. We can only guess that such plants are harmful to the animals in some way.

How Mangroves Get Their Mud

Mangroves, those ubiquitous and durable plants, are found along the coasts throughout most of trop¬ical Asia. In some áreas, they grow in such profu¬sión that even jungle conquerors like the U.S. Army Corps of Engineers found them impenetrable. But there are also great stretches where they will grow only sparsely. The reason for this lies not just in conditions at the seashore but in the composition of the great inland mountain ranges hundreds or even thousands of miles away. If the mountains are granite, which disintegrates into fertile mud on the long journey to the sea, mangrove jungles are almost certain to be found on the coast. But if they are sandstone, the unfertile silt left at the shore will not support massive mangrove colonies. A classic example is the Malay Peninsula, whose western coast harbors a steaming mangrove jungle while the wave-swept, sandy east coast is virtually barren.

Facts about Phineas T. Barnum

• Phineas T. Barnum (1810-1891) was an American showman with a genius for staging and promoting unusual events. 
• Barnum's claims about his shows were often exaggerated or false, and he con¬sidered himself a master of the art of "humbug," or fooling the people. Yet he was one of the first entrepreneurs to recognize the importance of publicity, using techniques such as brass bands and sensational advertisements to draw attention to his shows.
• P. T. Barnum was born on July 5, 1810, in Bethel, Connecticut. He began his show business career at age 25 in New York City, where he exhibited an aged woman named Joice Heth, claiming she had been George Washington's nurse. Hundreds of people paid to see Heth, said to be 161 years old.
• In 1841, Barnum acquired the American Museum in New York City, where he displayed amusing and astonishing oddities— both genuine and fake—including sword swallowers, giants, bearded ladies, and the midget known as General Tom Thumb. 
• In 1850 Barnum prometed and managed a highly successful American concert tour by the famous Swedish singer Jenny Lind.
• In 1871, Barnum launched a traveling circus that he billed as the "Greatest Show on Earth." Ten years later he joined his circus with that of a competitor, James A. Bailey.  
• Under Barnum and Bailey the spectacular three-ring   circus   became an American institution. 
• The Barnum and Bailey Cir¬cus was purchased by the Ringling Brothers in 1907.
• Barnum published an autobiography in 1855. He also was a member of the Con¬necticut state legislature and served one term as mayor of Bridgeport, Connecticut. He died in Bridgeport on April 7, 1891.

What is supersonic flight?

The term "supersonic" refers primarily to the flight or motion of any solid body through a gas at a velocity that exceeds the velocity of sound in that gas. When we speak of sound in this connection, we have in mind the pressure variations that move outward in all directions, in the form of waves, from a "disturbance" such as the tooting of a horn or the roar of a lion. The waves in question are usually very weak. When they strike our eardrums, they set up vibrations that are recorded in the brain so that we "hear" the disturbance that set off the waves. Of course, these pressure variations, or sound waves, as they are generally called, exist whether or not our eardrums and result in the sensation of hearing.
Sound waves traveling through the atmosphere near the Earth's surface have a velocity that decreases continually with altitude. It ranges from 1,120 feet per (762 miles per hour) at sea level. standard conditions of temperature and pressure, to 970 feet per second (660 per hour) at an altitude of 36,000. Then it remains constant to 82,000 feet altitude, after which it starts to increase.
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What are the airways?

  In the air between the airports are airways, or roads, through the sky along which the planes travel. Because of the many planes flying overhead, both during the day and night, it is necessary to set up rules for the road just as we have traffic rules for the cars on the streets.
  Except when taking off or landing, airplanes must fly at least 500 feet above the ground. Over cities and other
congested areas, the planes often have to fly 1,000 or even 2,000 feet above the ground.
  The route a plane takes is determined by the FAA which controls all air traffic. At major airports, there are men sitting before air maps, radios and con¬trol boards, and they keep track of every plane as it plows through the skies.
  Specific airways have been established to prevent planes from colliding in the air. All eastbound flights — planes flying from west to east — fly at oda thousand-foot levels, plus 500 feet, above sea level. Thus, a plane flying from Los Angeles to New York could fly at 15,500 feet. Westbound flights, on the other hand, fly at even thousand-foot levels, plus 500 feet, above sea level

Facts about David Alfaro Siqueiros

Self portrait - David A. Siqueiros

• David Alfaro Siqueiros was a Mexican painter, born in Chihuahua, and trained in art in Mexico City. From 1920 to 1922 he lived in Spain and Belgium. 
• After his return to Mexico, Siqueiros took part in the revival of fresco painting effected by govern-ment sponsorship of mural decorations in public buildings, and became one of the best-known Mexican painters, generally being ranked with Diego Rivera and José Clemente Orozco. 
• David Alfaro Siqueiros also participated in left-wing political activity, becoming a member of the Communist Party; in 1930 he served a term in prison for revolutionary agitation. Subsequently he was commissioned to execute frescoes in the United States. 
• His bold and vividly colored paintings, often representing contorted and intensely emotional figures, became famous throughout the West¬ern Hemisphere, and he received commissions to work in Uruguay and Argentina in 1932 and in Brazil in 1934.
• During the civil war in Spain, from 1936 to 1939, Siqueiros served with the Republican forces as a lieutenant colonel. 
• In 1940, after his return to México, Siqueiros was suspected by the police of complicity in the assassination in Mexico City of the Russian political exile Leon Trotsky. At first the Mexican government sought his arrest but later dropped all charges against him. 
• In 1946 David Alfaro Siqueiros went to Italy on the invitation of the Italian government and painted a number of frescoes in Rome. In addition to his mural paintings he executed many panel paintings, often in hard enamel. Among these panel paintings are "Proletarian Victim" (1933), "Collective Sui¬cide" (1936), "Echo of a Scream" (1937), and "The Sob" (1939).

Food for Fungi

  Fungi cannot make their own food. They use food that was made by green plants. They get their food from the things on which they grow.
  Bread mold takes food from the bread. It uses food that was made by wheat plants. Fruit molds use food that was made by the fruit trees.
  Some mushrooms take their food from the soil. They use the plant and animal materials in the soil.
  Mushrooms that grow on dead logs get food from the wood. They use food that was made by the tree when it was growing. Mushrooms that grow on a live tree use food that is made by the tree.
  Yeast plants do not grow until they are put into some kind of food. When they are added to bread dough and put in a warm place, they grow. They also grow in fruit juice. They use food that was made by green plants.
  In one way, fungí are like animals. They depend on green plants for their food.

The New General Catalogue (NGC)

Galaxy NGC 1300

  In 1874, the largest telescope in the world was owned by an amateur astronomer. At his ancestral home of Birr Castle, Ireland, the third Earl of Rosse, William Parsons, built what became known as the "Leviathan of Parsonstown". For its day, it was 'a monster-'—a 72 inch (1.8 m) diameter telescope slung on cables between two massive brick walls. With this unwieldy instrument. Rosse discovered that many "nebulas" had a spiral shape. Today we know them to be spiral, galaxies. Rosse himself rarely used the telescope, but many other keen observers did. Among them was Johann Louis Emil Dreyer. Dreyer served as Rosse's assistant from 1874 to 1878, recording the mysterious spiral nebulas, among others, with sketch pad and notebook.
  By 1886, Dreyer and other observers" had discovered so many nebulas and star clusters that a new catalog was needed. The Royal Astronomical Society assigned Dreyer the task. Published in 1888, the New General Catalogue (NGC) contained entries for 7,840 objects. The two Index Catalogues (IC) later added another 5,386 objects, some discovered with the newly invented process of photography. A century later, the 13,000-plus, objects-of the NGC and IC lists form the core of all of today's comprehensive databases of deep-sky wonders.

George Gershwin facts

• George Gershwin (1898-1937) was an American composer born in Brooklyn, New York. 
• Gershwin received some lessons from Rubin Goldmark, but was to a great extent self-taught. 
• Gershwin wrote the scores for many musical comedies including Lady Be Good, 1924; Strike up the Band, 1927; Girl Crazy, 1930; Of Thee I Sing, Pulitzer Prize play, 1931; Let 'Em Eat Cake, 1933; and the folk-opera Porgy and Bess, 1935. 
• Gershwin composed many orchestral pieces, notably The Rhapsody in Blue and An American in Paris, high points in the expression of American jazz. 
• George Gershwin died in Hollywood after a short illness.

How do scientists measure earthquakes?

Earthquakes around the world are monitored by seismologists (scientists who study earthquakes). They use Instruments called seismometers to register earthquake vibrations. Many seismometers are placed in remote areas and their Information is transmitted to central observation stations. Most modern seismometers are electronic. They monitor vibrations digitally (as numbers). Their information is then turned into a visual record of the shock waves, called a seismogram.
Simple, non-electronic seismometers produce a seismogram using a recording device, such as a pen, attached to a heavy weight. The weight and pen are suspended from a frame. A powered, rotating cylinder is also attached to the frame, which is secured to the ground. As the Earth shakes, the weight and pen remain still, but record the movement as the frame and the cylinder are shaken.
To understand the way in which simple seismometers work, tie a small, heavy weight, such as a pocket-sized plastic bottle full of liquid, to one end of a 1 meter (40 in) length of string. Hold the string at the other end and lift the weight off the floor. If you move your hand rapidly backward and forward, the weight will remain almost stationary. During an earthquake the weight and pen of a seismometer act in this way.
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What Does a Dam Do?

Dam

  As a barrier across a river or stream, a dam stops the flow of water. It then stores the water, creating a lake or reservoir, and raises the level of the water almost as high as the dam itself. The stored water is available for many uses. The dam also raises the water surface from the level of the original riverbed to a higher level. This
permits water to be diverted by the natural flow of gravity to adjacent lands. The stored water also flows through hydraulic turbines, producing electric power that is used in homes and industries. Water released from the dam in uniform quantities assures water for fish and other wildlife in the stream below the dam. Otherwise, the stream would go dry there. Water released in larger quantities permits river navigation throughout the year. Where dams create large reservoirs, floodwaters can be held back and released gradually over longer periods of time without overflowing riverbanks.
  Reservoirs or lakes created by dams provide recreational areas for boating and swimming. They give refuge to fish and wildlife. They help preserve farm-lands by reducing soil erosion. Much soil erosion occurs when rivers flood their valleys, and swift floodwaters carry off the rich topsoils.

What is the fastest animal?

  The fastest insect is probably the botfly which darts along at forty or fifty miles an hour.
  Dolphins are fast swimmers. They can keep up with motor boats traveling thirty miles an hour.
  The cheetah, most people agree, can go faster than any other four-legged animal. Its record is about seventy-five miles an hour. Hunters have trained cheetahs to pursue and kill swift-running antelopes and deer. And when there's nothing to hunt, a trained cheetah will race an automobile just for fun.
  Many naturalists think that the peregrine falcon (or duck hawk in North America) is the fastest bird. The Peregrine is renowned for its speed, reaching over 210 mph (325 km/h) during its characteristic hunting stoop, making it the fastest member of the animal kingdom.

What is nylon?

  Nylon is an artificial material made from air, coal, water, and petroleum and plant chemicals. Unlike cotton which grows on a plant, nylon is made in a laboratory or factory.
  Because nylon is strong, it is used for rugs, tubing, fishing lines and parachutes. Broad fibers of nylon make long-wearing brush bristles. It stretches well and thus makes stockings that fit readily.
  Nylon was developed in 1938 by a chemist, Dr. Wallace H. Carothers at Du Pont Company. He combined two organic chemicals— hexamethylene-dlamine and adipic acid by forming polymers of them. Du Pont engineers then had to devise ways to produce in quantity these two, formerly rare chemicals. They finally succeeded in making them from common materials (gases of air, etc.).
  To carry on the synthesis, the two compounds are heated by steam, then put under pressure. The semisolid nylon comes out as a flabby sheet that is ice-cooled to barden it.
  It can next be chopped into bits and stored. Fiber is made from the bits by reheating and thus melting them in an oxidation-preventing atmosphere (as in nitrogen gas). This melted nylon is forced through fine holes to come
out as fibers. A twisting and stretching process then lines up the nylon molecules to give a strong final product.

Thomas Gainsborough - painter

Thomas Gainsborough (1727-88) was one of the most famous of English portrait and landscape painters, was born in Sudbury, Suffolk. Early in life he showed his artistic talents and was sent to London to study. In 1743 after an unsuccessful attempt to establish himself in Hatton Carden, London, he settled in Ipswich, where he obtained work through Philip Thicknesse, governor of Landguard Fort, afterwards his first biographer. At his suggestion Gains-borough moved to Bath in 1760, and soon became a fashionable painter. He was one of the 36 original members (1768) of the Royal Academy; but being offended by the poor position given to his "Three Princesses" in 1784, he withdrew, and never exhibited again. In 1774 he left Bath, and settled in London.
Gainsborough was the rival of Reynolds in portraiture, and of Richard Wilson in landscape. He, more than any other artist, should be called the father of modern English painting and his influence as first of the impressionists can be traced through all contemporary art—in Constable, in the middle-Victorian landscapists, in the Glasgow school, in the New Eng¬lish Art Club. The greatest colorist of the early British school, he was rapid and facile in execution, dignified and graceful in expression, absolutely true to life and nature, and essentially English in sentiment.
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Natural gas

When white men first explored the Appalachian Mountains, their Indian guides had a strange sight to show them. In places there were fires that burned day and night on bare slopes where there seemed to be nothing to burn. No wonder the Indians thought the fires were mysterious! The fuel that was burning was one that no one can see. It was natural gas.
More than 150 years ago the people of a small city in western New York discovered natural gas coming out of cracks in the rock along the banks of a nearby creek. Some of the people piped the gas into their houses and burned it for light. The idea spread. A German scientist who saw gas lights in America called them the eighth wonder of the world.
Soon afterward, when people began to dig wells to get oil, natural gas came from many of the wells. It was a nuisance. Sometimes it caused explosions. Sometimes it caught on fire and set fire to the oil. To get rid of it, the oilmen piped it away and burned it.
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When the Monsoon Comes

Moonson rain

  No single element plays a more decisive role in the life of the far-flung realm of tropical Asia than the rain. On the plains of India, in parts of Burma, Thailand and Indonesia, where it is dry and dusty for half the year, men, plants and animals build their lives around the expectation of the seasonal rains— and when they come, they come on walls of towering clouds and change the landscape from seared brown to verdant green, from parched river bed to raging torrent. In other parts of the region, from the Malay Península southward and southeastward through the great are of the islands, steady rain throughout most of the year has shaped flora and fauna up to the highest mountain ridges. The ultimate determinants of this type of climate which is so characteristic of the Oriental region are winds—the monsoon winds, whose name derives from the Arabic word mausim, or "season." There is a regularity to these winds which has long fascinated meteorologists, and even today the challenging question of just why they blow at the times and in the manner that they do has not been answered to the entire satisfaction of the scientific mind. Basically, they arise from low pressure areas created by the heat of the sun in tropical regions. Where pressures are low, air from surrounding areas moves in—and these movements are felt tangibly as winds. In the heated, low pressure areas, the air rises, flowing outward at the apex of its rise, north and south in the respective hemispheres, toward the poles.
In Southeast Asia, this "weather machine" is peculiarly affected by the differential heating between land mass and ocean. Asia is the largest of the world's land masses, and in summer the sun, blazing down on its arid interior, warms the earth to such torrid extremes that the equatorial low pressure system moves northward toward the Tropic of Cancer. This now becomes the dominant low for the season, drawing in increasing air masses from surrounding regions— and the air that pours in from the south is saturated with moisture drawn up from the southern seas. All along the island are and over the drought-parched Indian plains this moisture-laden air, moving toward the heart of Asia, raleases its burden as rain.

The cholesterol problem

  The fatty alcohol called cholesterol is found in the cells of the body as well as in the blood stream; it is also present in bile salts and is one of the chief constituents of gallstones. In the blood stream. it protects the red blood cells from bacterial poisons, bile salts and other agents. If, however, it is present in excessive amounts, it can have certain undesirable effects. It may be deposited on the blood vessels and may lead to the serious condition called atherosclerosis, in which waxy cholesterol deposits are built up on the arterial linings. Gradually, they come to protrude into the lumen, or passageway, of arteries and thus reduce the supply of blood to a given organ.
  One method of dealing with this con¬dition has been to reduce the intake of foods rich in cholesterol, such as animal fats and egg yolk, and to substitute foods such as corn oil and cottonseed oil. It is by no means certain that such a diet will bring about a decrease in the amount of cholesterol in the body, since this substance is built up in the tissues (particularly in the liver) from various types of foods — carbohydrates, fats and proteins.
  There is some evidence that tension and stress may lead to a rise (at least a temporary rise) in the quantity of cholesterol in the blood. Tension causes the release of the hormone adrenaline; this hormone in turn, triggers the release of fatty materials from storage depots in the body, so that they may be available for conversion into energy. It would seem advisable therefore, for sufferers from atherosclerosis to avoid excitement as much as possible.

Who discovered oxygen?

  The English chemist and clergyman, Joseph Priestley, was once described as a man who had the art of making important discoveries by following the wrong theories. He was born near Leeds in 1733. Priestley was a nonconformist minister with an intense interest in science. A lasting friendship with the American statesman and scientist Benjamin Franklin led to his experiments in electricity. Then he turned to chemistry and discovered several gases, the most notable being oxygen. Priestley callad it dephlogisticated air. It was the French chemist Antoine Lavoisier who later gave it the name of oxygen. Priestley was a careless and unmethodical worker, with flashes of brilliance which inspired other men to follow up and complete his experiments. His political views were in advance of his time and found little support. His sympathies with the French revolutionary movement won him many enemies. In 1795 he left England and settled in America.

Who was John Deere?

  John Deere (1804-1886) was an American inventor and manufacturer. In 1837, he invented the first steel plow that efficiently turned the heavy American prairie sod. He became one of the world's greatest plowmakers.
  Deere was born in Rutland, Vt. He became a blacksmith's apprentice at the age of 17. In 1836, he opened a blacksmith shop in Grand Detour, Illinois. He soon learned that nearby farmers were dissatisfied with their plows. The heavy, gummy prairie sod stuck to the rough sur¬face of the wood or iron moldboard that was used to turn the soil.
  Deere built a smooth, hard moldboard out of an old circular steel saw in 1837. The new moldboard worked just as he had hoped. The soil fell away cleanly in furrows and polished the surface of the moldboard as it turned. Deere and a partner, Leonard Andruss, began making quantities of steel plows. Within 10 years, they were producing 1,000 plows annually. In 1847, Deere sold his interests to Andruss and started a new company in Moline, Illinois. To improve the quality of his plows, Deere ordered a special type of hard steel from England. He then had a similar type of steel made in Pittsburgh. This project resulted in the first plow steel ever manufactured in the United States. By 1857, Deere was producing 10,000 plows a year. The business was incorporated as Deere and Company in 1868. Today the company ranks as one of the largest industrial corporations in the United States.

Some Automobile Facts

  In 1885 a new type of vehicle appeared on the roads in Stuttgart, Germany. It looked much like some of the small steam carriages seen in other towns. But it differed in one important respect - its engine used gasoline as fuel. It was the ancestor of the modern automobile. Its inventor was named Karl Benz.
  In less than a century the automobile has developed into our most important form of transport, which greatly affects the way we live. Something like 300 million automobiles now travel on the world's roads. The latest ones are sleek vehicles, carefully streamlined so that they slip through the air easily. Some are designed for speed, being able to travel over 124 mph. Others are designed for economy, being able to travel over 45 miles on a US galon of gasoline. Many are built with the aid of robots.
  Automobiles are a very comfortable and convenient form of transport, but they have their disadvantages. They cause accidents; they burn a fuel obtained from oil, which will soon be in short supply, and they are a major source of pollution. For these reasons automobile manufacturers are continually redesigning their autos to make them safer, use less fuel, and cause less pollution. They are also experimenting with new kinds of engines that run on steam, hot air, and electricity. These should cause no pollution at all.

Facts about the deerhound dog

Scottish Deerhound

  Deerhound is a Scottish breed of dog, close to the Irish wolfhound in ancestry. It was named for its skill at deer hunting, but it is now seldom used for hunting. The deerhound is a member of the hound class of dogs. It is a rugged, but graceful, dog with a keen sense of smell. It measures from 28 to 32 inches (71 to 81 centimeters) tall at the shoulder, and weighs from 75 to 110 pounds (34 to 50 kilograms). The coat of the deerhound is 3 to 4 inches (8 to 10 centimeters) long, and is coarse and wiry. It may be gray, brindle, or wheaten in color. The deerhound makes an excellent pet.

The komondor breed

  The komondor is a large working dog that is native to Hungary. It is used to guard sheep and has also been used for police work and military services. The komondor stands about 28 inches tall at the shoulder and weighs about 90 pounds. It has medium-sized, hanging ears and a long tail that is usually carried ín a low curve. The komondor's pure white coat is long, dense, and woolly. There are very few komondors in the United States.
  The Komondor breed was brought to Europe by the Cumans and it was mentioned for the first time in 1544 in a Hungarian codex. This breed of dog has been declared one of Hungary’s national treasures, to be preserved and protected from modification.

How do astronomers measure the diameter of a star?

Since stars are too remote for any telescope to measure their diameters directly, how do astronomers know that Sirius is 1.8 times the diameter of our Sun or that Aldebaran is 45 times wider? The answer is indirect measuring techniques, which have yielded the diameters of several hundred stars.
The first method involves the precise electronic monitoring of a star when it is blocked out by the Moon. As the Moon makes its monthly orbital trek around Earth, it passes in front of many stars, but only occasionally are the stars bright enough for the detection equipment to complete the experiment. Although the technique is little more complicated than observing the length of time it takes for the star to disappear (which is almost instantaneous), it has revealed accurate diameters for several dozen stars.
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What are biomes?

Why do animals live where they do? Zoological realms provide only partial answers to this question; hence the concept of the biome, a smaller region. In the biome, now generally defined as an area controlled on land by climate, and distinguished on land or in the sea by the dominance of certain types of plants or ani¬mals, ecological relationships can be closely studied. Thus, for example, in colder regions a coniferous forest biome stands revealed: a forest dominated by cold-resisting evergreens whose superior adaptations and utilization of the available light, water and mineral nutrients limit the growth of other types of plants— and strongly influence the animal population.

BIOMES

Coniferous Forest
Young spruces and first begin to crowd out deciduous aspens in the coniferous forest bi¬ome. Evergreens domínate this broad belt, some 400 to 800 miles wide, which stretches across Canada, Alaska and Eurasia and, farther south, covers high mountains. Moose are found in the northern area, mule deer in the western mountains. One bird, the red crossbill, has a beak so specialized for picking seeds from cones that it can live only here.
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Some facts about flavors

  Candy comes in a number of different flavors. So does chewing gum. So do ice cream and puddings and many other kinds of desserts.

  The most popular flavoring for ice cream and cake is vanilla. A great deal of soft candy has vanilla in it, too. Vanilla comes from the seed pods of an orchid. No one in the Old World had ever heard of vanilla until the Spaniards conquered México about 400 years ago. The Spaniards learned how to make it from the Indians.

  These Indians were also using chocolate. Chocolate is now a very popular flavoring.

  Peppermint, spearmint, and winter-green are made from the leaves of mint and wintergreen plants. They are the best-liked flavorings for chewing gum.

  Peppermint and wintergreen are also used in hard candies. Many fruit flavorings are used in these candies, too. Lemon and orange flavorings are made from the rinds of lemons and oranges. Most fruit flavor¬ings are made from fruit juices.

  Actually the good taste flavorings give the things we eat is mostly a good smell. There are really only four tastes—bitter, sour, sweet, and salty. The rest of the taste of anything is its smell. Smell is a stronger sense than taste. If someone held a pear under your nose while you were eating an apple, the apple would taste like a pear.

  At first all flavorings were made from plants. Now scientists have learned other ways. Artificial vanilla, for instance, can now be made from coal tar!

The sense of weightlessness

  Bungee jump from a bridge or stall an aircraft, and you will feel as if your weight is reduced to zero. Astronauts experience the same sense of apparent weightiessness during space missions, where it is a source of both enjoyment and discomfort. The term "zero gravity "is sometimes applied to this state. Like the term "weightiess," however, it is somewhat misleading. Gravity is still present—gravity is what keeps the spacecraft in orbit. And although astronauts do not feel their own weight-in space, they are still attracted by Earth's gravitational field. What causes the sense of weightlessness is the fact that the astronauts and the spacecraft are falling together toward the Earth.
  Under such conditions, you do not walk, but float from place to place. Objects drift about and heavy items are easily lifted. Astronauts may experience temporary nausea, called space sickness, but more serious is a loss of muscle tone and bone strength, and a decrease in white, blood cells, which fight diseases. To deal with these effects, astronauts must perform special exercises during long space flights.

Did you know that fingernails grow at different rates?

  Nails grow at very different rates. Those on the fingers advance at about three or four times as rapidly as those on the toes. The fingernails on the longest fingers (the middle fingers) grow most quickly; those on the shortest or little fingers, most slowly. There appears to be no significant difference, with respect to growth, between the nails of the right and left hands. In summer the nails, like the hair, advance faster than in winter; the thumbnail, for instance, grows an average of one-ninth of an inch per month in the winter and one-seventh of an inch in the summer.
  Beyond providing a livelihood for manicurists and nail-polish manufacturers, the function of human nails is not clear. Fin-gernails can be used for scratching; they also provide a mechanical  support for the tips of the fingers and thus, perhaps, in¬crease the latter's efficiency as organs of touch. But human toenails, as far as we can see, serve no useful purpose, though they may have been useful at one time.

The saltiness of seawater

We have already know that cold water is heavier than warm and tends to sink. Salt, too, can make water heavy. On the whole, the proportion of salt in the open sea stays close to 3.5 percent. Near melting polar ice, however, the water tends to be less salty because the ice that is melting is nearly fresh. By contrast, the water near ice that is begin¬ning to form will have more than an average amount of salt since the ice that is in the process of freezing leaves extra salt behind in the water. Since this kind of water—both cold and salty—will sink the deepest, the heaviest water is found at the very bottom of the sea. Heavy water of this sort, loaded with salt from beneath the antarctic ice shelf, rides the ocean floor all the way to the equator and across it into the Northern Hemisphere. The ride takes a long time. Some scientists figure that 300 years pass before a bit of cold, salty, deep water goes from the Antarctic to the equator. Others say that it takes 1,500 years. By contrast, a bit of warm, relatively unsalty water may take only a year to make the surface circuit of the North Atlantic wheel.
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What does the psychiatric term fugue mean?

  Fugue in psychiatry means a pathological state in which an unacceptable and repressed part of personality gains control of the total personality. In this state the individual usually runs away from an in¬tolerable environmental situation and does not remember anything about his previous state. It differs from somnambulism in that the individual afflicted with fugue is in touch with his environment. He may buy a railway ticket, travel from place to place or even establish himself temporarily in some form of business. Fugue differs only in degree from multiple personality. If the secondary state is more complex and more permanent, it is looked upon as multiple personality. Sometimes the two are hard to difier¬entiate, since a fugue may lead to multiple personality. A fugue may last minutes, hours, months, or even years. Upon recovery, there is amnesia as to the fugue state.
  A case briefly stated may clarify the concept. A number of years ago, a bank clerk in Paris disappeared. Several months later he approached the police in Belgium and asked for help. It was established that he had worked for some time in a grocery store doing a good Job. All he remembered was that on his way home from the bank he felt a severe pain in his head. He could not tell how he got to Belgium.
  His life in París was intolerable since he had dificulties with his wife and mother-in-law. Circumstantial evidence pointed to him as an absconder of money from the bank. He "escaped" from this situation by "flight" into another country and different type of work.

Mount Fuji symmetry

Mt. Fuji poster

  FUJIYAMA (Mount Fuji) is a quiescent volcano and the highest mountain (alt. 12,388 ft.) of Japan, central Honshu, about 50 miles of Tokyo. Because of its beautiful symmetry and majesty, it is a favorite subject in Japanese art and literature. The word Fuji is believed to derive from the Ainu word meaning spirit of fire. In Fuji's last destructive eruption (1707-08) the surrounding provinces were covered with ashes to a depth of 10 feet in many places.

What is neon?

  Neon is one of the inert gases. Neon is element number 10 and was named from Greek word meaning "new." Sir William Ramsey discovered it in 1898.
  Neon is present in the air to the extent of about eighteen parts per million by weight. It is separated from the air by fractional distillation. Fractional distillation is the separation of the components of a mixture, like air, which have different boiling points by carefully controlled vaporization.
  Neon lights are used in many advertising signs. Electricity is passed through the gas and excites the electrons to a higher energy level. As the electrons return to the original level, light energy is given on. Neon lights give on an orange-red light.
  The most unusual thing about the inert gases is that they usually do not combine or react with other elements. The outer elec¬tron shell is closed. Neon (symbol Ne) has an atomic weight of 20.183.

Why is water an important solvent?

  Of all the different substances that can be solvents, water is the most important. Water carries dissolved nutrients in the body fluids of living things. Many of the liquids you use every day are water solutions.
  Water can dissolve so many different substances that it is often called the universal solvent. What makes water so special? The oxygen atom of a water molecule holds electrons more strongly than the hydrogen atoms. The shared electrons in the two covalent bonds, therefore, are drawn closer to the oxygen. As a result, the oxygen takes on a slightly negative charge and the hydrogens a slightly positive charge. Because of the molecule's shape, one end is positive and the other end negative.
  Water molecules can act as little magnets. The positive ends of water mole¬cules are attracted to solute particles that have a nega¬tive charge. The negative ends of water molecules are attracted to positively-charged solute particles.
  Water dissolves most ionic solids because its molecules pull apart the ions that make up the solid. Water can also form a solution with molecules that have slightly negative and slightly positive parts. However, because molecules of fats and oils have their electrical charges evenly distributed, they repel water molecules instead of attracting them.

What is the Gordian knot?

  According to legendary lore, Gordius, king of Phrygia, tied the neck yoke of his chariot to the pole with a knot so intricate that no one could untie it. An oracle, or tradition of the temple in which it was kept, ran to the effect that whosoever untied the knot should become master of Asia. Young Alexander, afterward called the Great, heard of this knot, and went with his companions to see it. After a careful examination, he drew his sword, it is said, and severed the yoke from the pole. Hence the proverbial expression of solving a difficulty "by cutting the Gordian knot."

THE DEFENSES OF PLANTS

There are a great many diíferent kinds of plant defenses. Certain types protect the plant from all kinds of dangers, while others are effective only against certain enemies. There are defensive devices that serve only to repel enemies; others may do considerable harm to any animals that may attempt to attack the plant.

Plant poisons are efficient defenses
Among the most efficient plant defenses are the plant poisons, which take effect when the plant is touched or eaten. It is interesting to note that not all parts of the plant are equally toxic, or poisonous. Most of the poisons are concentrated in the plant parts that are most susceptible to attack: the leaves, in which food is manufactured, and the fruits and flowers, which serve for reproduction.
Different poisons produce varying effects on diíferent animals. Poison ivy (Rhus toxlcodendron), for example, brings about a very unpleasant skin rash in human beings, but it serves as the main source of food for certain insects which devour the leaves of the plant.
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Ulysses S. Grant facts

  Ulyísses Simpson Grant (1822-1885) was the 18th President of the United States and a noted soldier. Born at Point Pleasant, Ohio, of Scots descent, he attended the military academy at West Point. As a second lieut. he fought with gallantry in Mexico, after which campaign he gave up soldiering for farming. He joined the Federal troops on the outbreak of the Civil War, and quickly became brigadier-general, the victories of Fort Donelson, 1862, and Vicksburg, 1863, gaining him the command of the army in 1864. His cam¬paign, involving great sacrifice of life among his own troops, was ultimately successful, and Lee's forces surrendered in 1865 after a series of fierce and bloody battles. Three years later he became President, serving two consecutive terms. After retiring from office he became a partner in a banking firm, which went bankrupt through the dishonesty of two of his co-partners, with the result that he was ruined. Slowly dying from a cancerous throat, he set to work writing his Personal Memoirs, hoping to retrieve his fortunes, but died four days after completing his task.

Solitaire games

Solitaire is a term applied to any game which can be played by one person alone. In the United States, the term "solitaire", like the term "patience" in England, denotes principally games played with a standard pack of fifty-two playing cards.
The origin of solitaire games is obscure; the most probable conjecture is that such games are derivatives of a group of sequence-building card games, known as stop, which have a history of several hundreds of years.
Solitaires are divided into two principal types, one in which the chance order of cards as shuffled by a player determines the outcome and another in which a player is permitted to use skill or judgment in rearranging cards so as to influence the final result.
Most solitaires are based on the problem of forming sequences in ascending or descending order, i.e., from the ace up to the king or from the king down to the ace, often in endless rotation. Suits have no comparative rank in these games, hearts and diamonds being called "red" and spades and clubs "black". The rules may require that sequences be built up in one color, in alternating colors, or in one suit alone; occasionally one or more of these methods is permitted in different parts of the game.
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Who was Vitus Bering?

  In the early I700's, many people still believed that a bridge of land connected Asia and North America. Vitus Bering (1680-1741), a Dane in the service of the czar of Russia, discovered that this land bridge did not exist. His explorations helped map what was at that time a little-known part of the world and led to the discovery of Alaska.
  Bering was born at Horsens, Denmark, in 1680, and entered the Russian Navy when he was 23. In 1724, Czar Peter the Great named him to lead an expedition to the Kamchatka Peninsula on the northeast coast of Siberia.
  The long journey across Siberia was filled with great hardships. After more than three years, the expedition finally reached a little village on Kamchatka. Bering had a ship built and in 1728 set sail across an uncharted sea, now called the Bering Sea. He discovered an island, which he named St. Lawrence Island. Then he sailed north through the strait (now called Bering Strait) that separates Asia and North America. The discovery of this strait proved the two continents were not linked.
  Bering returned to Russia in 1730 to report his findings and to plan a new expedition. In 1741 he sailed from Kamchatka again with two ships—his, the St. Peter, and the St. Paul, which was commanded by Aleksei Chi-rikov. The ships soon drifted apart, and on July 15-16 both Chirikov and Bering sighted the southern coast of Alaska from different points. The St. Peter stopped briefly at Kayak Island. But before exploring farther, Bering, who was ill, decided to return to Kamchatka for the winter. On the return voyage the St. Peter was buffeted by violent storms and wrecked on an uninhabited island off the coast of Kamchatka. Here, on December 8, 1741, Bering died and was buried. The island now bears his name.

Where the energy begins

Hoover Dam is only one of the big dams in the United States. It is on the Arizona-Nevada border. Day and night the wheels turn around to supply us with electric energy.
As you can see, rivers and other bodies of water have a great deal of energy. Where did all this energy begin? What happens when the Sun shines on a puddle? Heat from the Sun changes the water to water vapor. The water vapor goes into the air. Some of it goes up high ano! forms clouds.
Raindrops fall from the clouds. Gravity pulls them down to the Earth. The water keeps falling downward from high places. Rivers flow downhill. Water rushes over cliffs and dams. Gravity makes the water flow from high places to low. This goes on year after year.
All the energy from moving water depends on the Sun. If the Sun stopped shining, no clouds would form, no rain would fall. There would be no way that water could get uphill for gravity to pull it downhill again. There would be no more energy from rivers and waterfalls.
But the Sun does shine. The rain falls. The rivers flow. Water does keep moving. We can keep using the energy from moving water.

How old is the rocket principie?

  Historical records show that as early as 800 years before Christ, the Chinese — who were the first to discover gunpowder — were shooting powder-packed tubes on a stick into the air to amuse their people.
These rockets followed all three of Sir Isaac Newton's three laws of motion. Mainly, however, it was Newton's third law which was in effect: For every action, there is an equal and opposite reaction. Thus, when the rocket's burning gases thrust downward, the opposite reaction is a thrust upward, sending the rocket in a fiery are into the night sky.
  In the 1700's William Congreve, in England, tested improved Chinese rockets as weapons of war. They achieved little success at the time, although when Francis Scott Key wrote the Star Spangled Banner during the War of 1812, the phrase, "the rockets' red glare" referred to Congreve missiles fired by the British against Fort McHenry.
  The real father of modern rocketry was the American, Dr. Robert Goddard, a physics professor who, in the early 1900's, began experiments with rockets to send weather-recording instruments higher than meteorological balloons had ever gone.
  He tried both solid fuel (powder) and liquid fuel (gasoline and oxygen), and in 1926 the world's first liquid-propelled rocket was successfully fired at Auburn, Massachusetts.
  Starting with his first crude apparatus, he went on to add guidance features, an automatic parachute to bring recording instruments back to earth safely, and subsequently developed the principie of the multistage rocket which, forty years later, was used to put both United States and Russian satellites into orbit around the Earth.
Goddard's first rocket

How does an electric refrigerator work?

  You can do some refrigerating if you put a drop of perfume or shaving lotion or liquid vanilla flavor on the tip of your nose. In a moment or two the liquid dries away into the air, and the spot on your nose feels much cooler. We say that the liquid evaporated. When liquids evaporate they carry heat away with them.
  Inside your kitchen refrigerator a special liquid in a long metal pipe does the cooling job. The liquid, called freon, evaporates very fast, and so it makes things cold very quickly. It travels around and around in the pipe, so it can be used over and over.
The freon travels first to the part of the refrigerator that holds the food. There it evaporates. Then, carrying heat with it, it goes on through the pipe, out of the refrigerator box, to a radiator where it gets rid of the heat it collected inside the box. Now the freon is ready lo return and carry away more heat, keeping the refrigerator cold.
  The electric machinery in the refrigerator runs a pump that pushes the freon around and around through the pipe.

How earthquakes happen?

  Earthquakes occur at cracks in the Earth's crust called faults. Faults are created because rock is brittle and breaks when great stress (stretching, squeezing or twisting) is exerted upon it. Stress builds up in areas of the crust because of the gradual movement of the Earth's plates.
  Earthquakes happen when stress has built up in an area of rock to such an extent that sudden movement occurs. This movement can create a new fault as the rock breaks at the weakest point, or the movement causes the rock to slip along an existing fault. When this happens, an enormous amount of enorgy is given out as the stress is released. The released energy causes the surrounding rock to vibrate, which creates an earthquake
The actual point where the rock first slips or breaks, causing an earthquake, is called the focus. The place on the Earth's surface immediately above the focus is called the epicentre.


Shock waves
  The vibrations of an earthquake travel out through the Earth. Scientists call them shock waves or seismic waves (from the Greek word seismos which means "trembling Earth"). Different types of shock waves are sent out from the focus, and each type makes the rock it travels through víbrate in a different way.
  The main types of shock waves are called primary and secondary waves. Primary waves, or P-waves, squeeze and stretch the rock they travel through. Secondary waves, or S-waves, move the rock up and down, like a roller coaster, and also sideways at the same time. Other types of shock waves, called surface waves, have other shaking effects. These do not occur in all earthquakes, but when they do occur, they are capable of causing damage far away from the epicentre.

Mauna Loa, the largest active volcano

eruption at Mauna Loa

  Mauna Loa (Long Mountain) lies to the south of Mauna Kea and, like it, rises from a plain 18,000 feet below sea level. Mauna Loa is 13,675 feet high; it is the largest active volcano in the world. Its dimensions are quite staggering; it is about sixty miles across and two hundred miles in circumference at sea level. At the summit there is a huge crater, which is called Mokuaweoweo. This crater is five miles in circumference; the cliffs around its pit are from 500 to 600 feet high. There is considerable volcanic activity in Mokua¬weoweo, particularly before an eruption; white-hot fountains of lava rise to a height of several feet. However, there have been no flows of lava from this crater, at least in historie times. All the lava discharges from Mauna Loa come from the flanks of the mountain, at elevations of from 7,000 to 13,000 feet.

Some historic Mauna Loa lava flows
  There have been numerous eruptions in the past hundred years or so, at intervals of a few years. The eruption of 1873-74 lasted eighteen months; that of 1880-81, nine months. In 1926, a lava flow from a crevice in the southeastern side of the mountain destroyed the village of Hoopuloa, on the coast. This flow was thirty feet high, and advanced along a front of about a hundred feet at the rate of three feet a minute. Thomas A. Jaggar, director of the Hawaiian Volcano Observatory, compared the flow to the lumbering advance of a caterpillar tractor. Said he: "An upper layer of boulders and paste is rolled forward on a viscous red-hot paste inside, tumbles down at the front in a debris slope and this is eternally overridden by the advancing mass for which it lays the track."
  In 1935, the city of Hilo was threatened by a lava flow proceeding from the northwest flank of Mauna Loa. The United States Army Air Corps (it is now a sep¬arate military arm) came to the rescue. A fleet of bombers dropped 6,000 pounds of bombs from a height of about 5,000 feet above the lava. The bursting bombs opened up new channels for the lava flow, diverted its course, and saved the city.

Francisco de Goya

painting by Goya

  Francisco José de Goya y Lucientes (1746-1828) was a Spanish painter and etcher, born in Fuentetodos, in the province of Aragon, and studied for a time at Saragossa. He proceeded to Madrid at the age of 19, but was soon traveling with a troupe of bull-fighters, ultimately finding his way to Italy, where he apparently settled down to study his art once more. In 1771 he returned to Saragossa, where he remained for four years, painting frescoes in the cathedral and elsewhere. He then went again to Ma¬drid, where the cartoons he designed for tapestries soon won him great admiration. In 1786 he was estabished as a Court painter, producing his astonishingly truthful and revealing series of royal portraits. His work during this period includes his fine portrait of the Duchess of Alva, who seems to have been his close friend. He spent his later years at Bordeaux.

Who was Ixion?

In Greek mythology, Ixion is the king of the Lapithae. According to Greek tradition he was the first murderer of a kinsman. Married to Dia, the daughter of Eïoneus, Ixion refused to pay his father-in-law the promised bride-price and had him killed. Since no mortal consented to cleanse him of his crime, Zeus, the ruler of the gods, carried Ixion to Olympus to be purified. Ungrateful and impious, Ixion made improper advances to Hera, queen of the gods. In revenge, Zeus created a cloud in Hera's shape, by which Ixion fathered the monster race of centaurs. Ixion was then punished by being chained to a fiery wheel, which re¬volved perpetually in Hades.

What is a geyser?

Old Faithful

  A geyser is a special kind of hot spring. Hot water does not flow from a geyser all the time as it does from a hot spring. Instead, a geyser is quiet for a time. Then it suddenly erupts and shoots water high into the air.
For a geyser, there must be hot rock not far below the surface of the ground. There must also be a narrow, crooked passage leading up from the hot rock.
  The eruption of a geyser comes about in this way: Water fills the crooked passage. The water at the bottom gets very hot. If the passage were big and straight, the cold water at the top would gradually sink down and push up the hot water. As it is, the hot water is bottled up. It gets so hot that it begins to boil and form steam. The steam pushes some of the cold water out of the top of the tube. As soon as a little comes out, there is less cold water to press down on the hot water. The hot water then changes to steam very fast and shoots the water above it high into the air.
  Geysers are found in only a few places. There are about 200 in Yellowstone Na-tional Park in Wyoming. There are also some in Iceland and New Zealand.
  The most famous geyser is Old Faithful in Yellowstone Park. It erupts every 65 minutes or so. Visitors seldom have to wait more than an hour to see Old Faithful perform.

Zodiac constellations

  The Earth, the Sun, the Moon, and most of the planets are almost on the same level. One might say that they are spinning around on a very large saucer in space. The Sun is in the middle of the saucer. Far out beyond the path of the farthest planet are stars on this same level. Ancient people recognized twelve constellations that form a background for the imaginary path that the Moon, the Sun, and the planets trace out in the sky. Eleven of these constellations are animals (including men and women). The twelfth is Libra, the Scales. An¬cient star watchers gave this band of constellations the name zodiac. Zodiac means "of living things."
  The zodiac, then, is a circle of twelve constellations that surround man's solar system. The Sun, the Moon, and most of the planets seem to move along this path in front of these twelve constellations. When the Sun is between the Earth and a certain constellation of the zodiac, the Sun is said to be "in" that constellation. The zodiac is divided into twelve equal parts. The Sun occupies each part for about one month. The constellations and the signs of the zodiac are Leo, Virgo, Libra, Scorpius, Sagittarius, Capricornus, Aquarius, Pisces, Aries, Taurus, Gemini, and Cancer.

zodiac constellations