Veterinary medicine

   Veterinary medicine is the branch of medicine that deals with the sickness of animals other than man.
   The most important activities of the veterinary doctor are found on the farm, where he treats livestock and tries to prevent large-scale outbreak of animal diseases.
   Some veterinarians work for the Public Health Service, inspecting meat and dairy products. Others work to keep the animals healthy in zoos and circuses, many are employed by the government to care for the nation's wildlife, others care for pets.

Who was Andreas Vesalius?

   Andreas Vesalius (1514-1564) was a Belgian physician who was the founder of modern anatomy. He was born in Brussels, and as a child spent many hours dissecting dead mice and other small animals. He studied medicine at the University of Louvain in Paris, where he recognized, even as a student, that much of the information concerning anatomy was in error.
   On his graduation at the age of 23 he was appointed Professor of Surgery and Anatomy at the University of Padua in Italy.
   Vesalius was a brilliant doctor and an inspiring teacher. At the insistence of his pupils, he published, at the age of 24, his Anatomic Tables. This was followed by Concerning the Fabric of the Human Body, the first complete and systematic description of the human body. The publication of these works increased his popularity as a teacher and man of medicine, arousing the jealousy of his former teachers at the University of Louvain, and other physicians who were already taking credit for some of his work. Deeply hurt by the hostility, Vesalius resigned from the University, burned his remaining published notes and ended his teaching career in 1544, at the age of thirty.
   During the following twenty years he served as court surgeon to Charles V and Phillip II of France. His fame as a surgeon spread throughout the world, but teaching was the love of his life.
   In 1564, while on a pilgrimage to Jerusalem Vesalius received word that he had been reappointed to his teaching post in Padua, but before he could return and accept the honor he died on the island of Tante.

What is vertigo?

 Vertigo is a symptom of a physical disorder or disease of the body. Vertigo is characterized by a sensation of dizziness, fainting, partial loss of consciousness, loss of equilibrium, or leaning to one side.
   Simple vertigo usually lasts about two weeks, but other cases of this distressing symptom last until correct diagnosis is made and the cause is correctly treated. Infections, eye trouble, brain injuries, bad teeth, drugs, and seasickness all produce different degrees of vertigo.

What is a Flea?

   A flea is a wingless, blood-sucking insect about 1/16 inch long. A parasite af man and other mammals, it has mouth parts formed for piercing and sucking. Its eggs are laid in unclean places and the maggot larvae are legless and equipped for biting. The complete metamorphosis from larva to pupa to flea takes from four to six weeks. The flea is remarkable for its strength and agility, being able to leap a distance of 200 times its length. Several species are known to be active in spreading the bacilli of bubonic plague by sucking the blood of infected rats and then the blood of man. Other diseases are similarly transmitted.

What is a flea circus?

   A flea circus is an exhibition of fleas apparently engaged in moving tiny objects, playing musical instruments, dancing, dueling, and the like. Fleas are not actually trained to do these things, but their natural movements can be obstructed in such ingenious ways that they appear to push, pull, or carry objects when they are merely trying to struggle free or to grasp something.

   The trainer usually picks female fleas for his circus, since they are larger, stronger, and more agile than the male. Many are able to jump many times their own length and to pull objects that weigh 1,200 times their own weight.

What is a firecracker?

   A firecracker is a kind of fireworks that explodes and makes a noise resembling gunfire. One of the commonest and most inexpensive of fireworks, firecrackers are now illegal in most states of the United States because they are so very dangerous.
   The small firecracker, or Chinese cracker, is a small paper tube filled with charcoal and gunpowder. A chemically treated piece of string is used for a fuse. The United States once imported millions of these from China for U.S. Independence Day (Fourth of July) celebrations.
   An American variant of the Chinese cracker was the cannon cracker. It was merely an enlarged version of the Chinese cracker. Often 1 foot long and 2 inches wide, it was usually loaded with a large amount of blasting powder. These extremely dangerous firecrackers were mainly responsible for the large number of people killed, blinded, and wounded on the Fourth of July.
   Firecrackers are used in military training to simulate the sound of gunfire. Because they are so dangerous, firecrackers should not be used for celebrations, even where legal.

Gadwall (duck)

   The gadwall is a swift-flying river duck related to the mallard and often hunted for sport. The gadwall ranges from 19 to 21 inches long and weighs about 2 pounds. The male is mainly gray-brown, with black around the tail and a whitish belly. The female is mottled brown with a yellow-tinged bill. Both sexes have a small white patch on the wings.
   The gadwall lives on creeks and ponds throughout the Northern Hemisphere. Like other dabbling ducks, it tips the front part of its body into shallow water to feed on plants. Gadwalls build down-lined nests in dense grass or bushes. The females lay from 7 to 13 white eggs.
   The gadwall, Anas strepera, is classified in the order Anseriformes, family Anatidae.

Gadwall

Water beetles

   Water Beetles are beetles which live on or in the water, especially the somewhat simi­lar Amphizoideae Haliplidae, Dytiscidae, and Gyrinidae, and also the quite different clavicorn Hydrophilidae. The Dytiscus, common in stagnant water, is olive-green above, and oval in shape. The respiratory organs of the perfect insect are not adapted to obtaining air from the water; the creature must therefore come occasionally for air to the surface of the water, where it lies on its back, to expose the openings of its airtubes, which are in the last segment of the abdomen.

What are zinnias

   Zinnias are brightly-colored flowers that came from Mexico and the southwest part of the United States. They are called composite flowers because the parts that look like colored petals are small flowers. The small flowers are grouped to make a flowerhead.
   The stem is stiff and hairy, and the leaves are rough and somewhat sticky. The flowers range in color from scarlet, salmon, rose, purple, orange, and yellow, to white. Moths and butterflies pollinate zinnias. Zinnias also attract hummingbirds.
   The California giant zinnias grow to three feet. Flowers of the giant zinnias often exceed six inches across. Zinnias grow well in ordinary well-drained soil with full sun. They grow easily from seeds which germinate in five days. The seeds can be started in a cold frame and transplanted later to open ground.
   Dwarf zinnias make attractive border plants. If the flower heads are removed before seeds are formed, the plant will continue to bloom. The double zinnia is of French origin.

What is zinc?

   Zinc is a hard, silvery metal belonging to the nonferrous metal group. In nature zinc rarely occurs as a free element. It is widely distributed in compounds, such as franklinite, a zinc-iron manganese mineral; willemite, a zinc silicate; and zincite, a zinc oxide.
   After segregation of the mineral into concentrates, the ore goes to the smelters where the distillation, or retort, method is used. After being roasted and reduced in a retort furnace, the metallic zinc is then boiled to a vapor and condensed as pure zinc. For high grade zinc, the electrolytic method of refinement is used.
   Since zinc melts easily and does not rust, it is used for galvanizing steel and iron products, such as buckets, wires, and pipes. It is a main alloying constituent of brass. Zinc (symbol Zn) has atomic number 30. Its atomic weight is 65.37 (65.38, O = 16). It has a density of 7.14 gm/cc and a melting point of 419 °C.

Zircon mineral

   A zircon is a mineral which is found in some kinds of rock and limestone. Zircons are sometimes found in sandy stream beds and on beaches, but more often in the same waters where prospectors pan for gold.
   Most zircons are found in the Ural Mountains of Russia, in Ceylon, in Australia, and in the United States in Florida, California, and Oregon. Some zircons are used in jewelry. These shiny, glittery stones are brittle and chip easily. Colorless zircons that resemble diamonds are called jargoons. Transparent stones with a reddish color are called hyacinth zircons. Industry uses zircons in making heat-resistant porcelains, chemicals, abrasives, foundry sand, alloys, and in refining zirconium.

Zoo

   A zoo is a place in which live animals are kept on exhibit for the education of the public and for scientific study. Zoos are usually in parks; the name "zoo" comes from the term zoological garden.

   Many people who will never be able to travel over the world are able, through the zoo, to see and to learn about the animal life in other countries. Many discoveries about the habits, breeding, and illnesses of animals have been made in zoos. One of the most important contributions of the zoo is that of preserving wildlife which is becoming extinct.

   A good zoo creates excellent conditions for the animals. It will have a kitchen for preparing healthful meals that the animals will enjoy. Some zoos even bake a special kind of bread for the bears.

What is weightlessness?

   Weightlessness, or zero-g, is demonstrated by a falling body. No resistance is offered to the body as its mass attempts to follow the gravitational pull of Earth. The greater the mass of the body, the greater must be the resistance to prevent the body from falling. If resistance, or support, is measured by placing the body on a scale, its "weight" is measured. If no resistance or support is offered, and the body falls freely, it no longer has any weight. Bodies in orbit, such as the Moon, the Earth or a space ship, fall freely. The Moon falls in the Earth's gravitational field, and the Earth in the Sun's.
   What causes a body on Earth or the Moon to have weight is the comparatively large mass of these bodies. A space ship does not have such a mass and therefore does not affect the bodies within its confines which fall freely together with the space ship, hence are weightless.

What is bleaching?

   The method for whitening cloth, paper, or any material is called bleaching. If you would like to see bleaching in action, try the following experiment.

   Stir a few drops of ink into half a glass of water. Add two or three drops of chlorine laundry bleach. (Be careful not to let the bleach touch your skin. It is very strong and could burn you.) You will see the ink in the glass lose color as the bleach is added.

   Chlorine bleach is good for whitening cotton and linen. So is hydrogen peroxide. Some people use hydrogen peroxide to turn their hair blond. Silk and wool are bleached by wetting them and exposing them to the gas sulfur dioxide. Sulfur dioxide is the gas you smell when a match has just been lit. More than 3,000 years ago, the Egyptians and Babylonians bleached by spreading wet cloth on a surface exposed to the rays of the sun.

Who was John C. Fremont?

   John Charles Fremont (1813-1890), was an American general and explorer, born at Savannah, Ga. He spent the years 1838-1839 exploring the area between the Missouri River and the British frontier and obtained a lieutenant's commission with the U.S. Topographical Corps. In 1842, with governmental approval, Fremont led a small exploration party through the Wind River Range in the Rocky Mountains. Upon returning, he reported extensively on the meteorology, botany, geology, and geography of the region and designated points later fortified by the United States. In 1845 he cleared northern California of Mexican troops, but in pursuit of this goal he became involved with American authorities in California, the result of which was a court-martial (1846-1847). Having been found guilty of mutiny and other charges, he resigned from the army in 1848. Five years later he made his fifth expedition across the continent. In 1856 he was the first Republican candidate for the presidency, and in 1861 President Abraham Lincoln appointed him a major general in command of the western Union army, a position he lost because of a dispute with a subordinate. He was territorial governor of Arizona from 1878 to 1883.

What is Free Trade?

    Free trade is the economic doctrine that would allow goods to flow freely on the world market without the impediment of tariffs. On a regional basis free trade has sometimes been achieved. Trade within the United States, for example, is unhampered by tariff barriers between the states. Internationally, however, free trade is an ideal that has never been fully realized.
    The economic argument for free trade is a compelling one. Free trade is the application of the economic doctrine of comparative costs. This means that each nation will produce those goods that it can produce most easily. Suppose the United States enjoys its greatest advantage over nation X in the production of automobiles. Comparative costs will show that both nations will benefit if the United States produces autos for export and imports from nation X a product, say, shoes, that that nation produces more easily than the United States. This is what free trade allows. Free trade will result in each nation's producing that which it can produce most abundantly, in each nation's obtaining its greatest possible surplus of buying power, and in consumers throughout the world being allowed to purchase goods at the lowest possible prices.
    Free trade has few economic flaws. The reasons why free trade has never been fully put into practice internationally are political and military. Nations do not want to spe¬cialize in goods that do not add to their industrial and military strength. The result is that con¬sumers must pay more for goods.

The Aardvark enemies

aardvark

   The aardvark's main enemies are man, hunting dogs, pythons, lions, cheetahs and leopards, and also the ratel, while warthogs will eat the young. When suspicious it sits up kangaroo-like on its hind quarters, supported by its tail, the better to detect danger. If the danger is imminent the aardvark runs to its burrow or digs a new one; if cornered, it fights back by striking with the tail or feet, even rolling on its back to strike with all four feet together.
   On one occasion, when an aardvark had been killed by a lion, the ground was torn up in all directions, suggesting that the termite-eater had given the carnivore a tough struggle for its meal. However, flight and —above all —superb digging ability are the aardvark's first lines of defence for as with other animals with acute senses like moles and shrews, even a moderate blow on the head is fatal.

What is Leporidae?

    Leporidae is a family of animals comprising the rabbits and bares. With the Lagomyidae it constitutes the suborder Duplicidentata, distinguished from the rodents by having two pairs of upper incisors, of which the second is much reduced in size and placed immediately behind the first and larger pair. The hind-legs are much longer than the fore-legs and are well adapted by their structure for the leaping mode of locomotion affected by these animals; the tibia and fíbula are completely ankylosed and articulate with the calcaneum by a pulley-like surface, thus combining great strength with great freedom of movement in one plane. The family is now cosmopolitan, some 75 species and sub-species being recognized in North America. The genus Lepus is practically coextensive with the family.

Arctic hare

The rattling Thick-spined Porcupine

A RATTLING PORCUPINE
Although quills are an excellent defense for all porcupines, there is still the chance that an inexperienced predator or other large animal will tangle with one of these prickly animals, and while getting badly stuck itself, will still damage the porcupine by trying to eat it or accidentally treading on it. The next step, therefore, is to advertise that one is prickly and dangerous, and that is what a porcu­pine of Borneo does. Hystrix crassispinis has a cluster of hollow quills with open ends on its tail. When the tail is shaken, they rattle, making a warning noise, and other animals learn to avoid this sound just as they must the warning of an aroused rattlesnake.

Who was Sigmund Romberg?

   Sigmund Romberg (1887-1951), was a famous composer of operettas. They include Maytime; Blossom Time, based on the life and music of Franz Schubert; and The Student Prince. He wrote more than 70 musical shows, among them Rose of Stamboul, The New Moon, The Desert Song, and Up in Central Park. His musical comedies include Follow Me and Over the Top.
   Romberg was born in Hungary, and studied at the University of Bucharest. He trained as an engineer, but also studied music in Vienna. He came to the United States in 1909. Romberg's theatrical career began when he became a staff composer for the Winter Garden Theater in New York City, writing music for The Passing Show. He gained his first success with The Midnight Girl in 1913. Romberg settled then in New York City, but later moved to Hollywood, where he wrote music for motion pictures. Many of his operettas were made into motion pictures.

The Romanov rulers

   Romanov was the name of the imperial family which ruled Russia from 1613 to 1917. The Romanovs came from Lithuania or Germanv. They became Russian landholders and reached a high position when Czar Ivan IV married Anastasia Romanov in 1547. Her nephew became leader of the church. His son Michael was elected czar in 1613. Michael's son, Alexis I, acquired the Ukraine and brought the church under czarist control.
   Fifteen more Romanov rulers followed. The most famous was Peter the Great. The imperial family died out in 1762, but the rulers kept the Romanov name down to Nicholas II, who was deposed in 1917. He and his immediate family were executed in July, 1918, but other members of the Romanov family escaped from Russia and survived.

Ibex

Ibex

   The Ibex is a wild goat. There are several species found in the mountain ranges of Europe, Asia, and Africa. The common ibex of the Caucasus, the Alps, and the Apennines is a brownish gray animal about 4½ feet (1.35 m) long and something less than three feet  (.90 m) high. The ibex is a fine mountain climber, like the chamois in its habits, with a pair of large backward-curving horns that sometimes attain a length of three feet. The ibex is, of course, a game animal, attaining a weight of perhaps 200 pounds (90 kg).

The goshawk bird

   The goshawk is a fine, large hawk of the falcon family. The name is derived from an old English word meaning a goose hawk, or a hawk used to take geese. Falconers train the goshawk to take rabbits and hares as well. Unlike the falcon that strikes from above, the goshawk follows its prey in a straight line and strikes from behind. The female is about twenty-four inches in extreme length. The male is smaller. Both sexes are slaty blue on the upper parts. The under parts are cross-barred with dark color on a whitish ground. The American goshawk nests in Canada, but winters as far south as Vir­ginia. It is bluer in color than the common henhawk. A naturalist says of this species: "It is the most daring of all the hawks, and while in pursuit of its prey is apparently less concerned by the presence of man than any other. It will dart down unexpectedly at the feet of the farmer and carry off the fowl." A pair of these hawks will extermínate a flock of prairie chickens or ptarmigans.

What is a foundry?

   A foundry is a building or group of buildings in which pig iron, aluminum, brass, bronze, steel, or other metal is melted and cast into shape. The most important installations in a modern foundry are the furnace for melting the metal and the patterns and molds for casting it into various shapes. Iron is more commonly used than steel for castings because it does not warp or crack when near heat. Also iron melts at a lower temperature than steel, and it is hard and wear resistant. Iron for casting is melted in several kinds of furnaces. The most important is the cupola, a furnace in which steel scrap, iron scrap, pig iron, and coke are used. The molds, or patterns, for casting must be accurate and must allow for the shrinkage of metal. There is much variety both in the shapes of molds and the materials for making them, although molds and cores are usually made of sand.

Food poisoning

   Food poisoning is of two general types: that caused by food contaminated with certain bacteria or bacterial toxins and that caused by plants or animals that are in themselves poisonous.

   Bacterial Food Poisoning. The principal bacterial food contaminants are the Salmonella group of organisms and, rarely, the colon bacillus. The principal bacterial toxins causing food poisoning are those produced by the staphylococcus and by the organism that causes botulism.
   Salmonella food poisoning usually occurs in epidemics, symptoms of food poisoning appearing suddenly in a group of persons who have eaten the same food. Nausea, colic, diarrhea, and fever are common symptoms. Recovery occurs in a few days, and deaths are rare.
   Staphylococcus food poisoning is probably the commonest form of epidemic food poisoning. A toxin is produced by some strains of staphylococcus and upon ingestion causes gastrointestinal symptoms. Good mediums for production of the toxin are pastries containing cream, custards, whipped cream, cottage cheese, milk, butter, cold meat, gravy, and salad dressing. Nausea, vomiting, cramps, and diarrhea are the usual symptoms. The attack usually lasts about a day.
   Botulism is one of the most serious forms of food poisoning and has a high death rate.

   Nonbacterial Food Poisoning. This type of poisoning can occur after the ingestion of certain species of mushroom, immature or sprouting potatoes, certain sea foods (such as mussels), grain contaminated with ergot fungus, fruits sprayed with lead or arsenic, or food stored in cadmium-lined containers. The most severe and fatal forms are mushroom and mussel poisoning.

Food cycle

   Food cycle is the continuous natural cycle that involves the synthesis of food from inorganic substances, the elaboration of this food into protoplasm, and the breaking down of protoplasm to these same inorganic substances.

   The food cycle begins with the absorption by green plants of carbon dioxide from the atmosphere and of water from the soil. By means of photosynthesis green plants manufacture sugar from these inorganic substances and convert the radiant energy of sunlight into the chemical energy of the sugar. Green plants also absorb inorganic nitrates from the soil and elaborate proteins from them. This sugar and these proteins serve as food for the plants. The plants assimilate them and transform them into the living protoplasm that composes their tissues.

Killdeer bird

   "Kill-deer, kill-deer" is the noisy cry and the name of a bird of the plover family. This cry is a warning to other birds when danger is near. The killdeers fake injuries to lead strangers away from their nests. These nests are on the ground. Spotted, blotched, buff-colored eggs are pointed at one end. The eggs are positioned in the nest so that the pointed ends always touch. Baby killdeer are completely feathered when hatched and look like tiny, scampering brown balls. Killdeers run or walk but never hop like many birds. Basically, they are North and South American shore or wading birds but also are found far from water.

Domestic animals

    No one knows who first discovered that some wild animals could be tamed and raised. We do know that the discovery came about back in the days when most tools and weapons were still being made of stone. At about the same time that animals were first tamed, plants were tamed, too. The taming of animals and plants was important for several reasons. One big reason was that people no longer had to spend most of their time hunting for food.
   Thinking of a big city like New York helps us see how important it was to find out that animals and plants could be raised for food. Imagine all the millions of people in New York starting out in the morning to shoot deer or rabbits and to gather roots and berries!
   But not all our domesticated animals were tamed to furnish food. We do not eat dogs and cats. They do not furnish milk for us to use. Probably they were first tamed to be companions. Later, dogs helped with the hunt and learned to guard property. In time some were trained to pull sleds or carts, and much later to act as eyes for blind people. Cats came to be liked for their help in killing rats and mice.
   Camels, donkeys, and llamas were tamed to be beasts of burden. Perhaps horses were, too. But they may have been raised first for food.
   Although sheep were first raised for their meat, people soon found that their wool makes good cloth. People also found that the skins of cattle and goats and pigs make good leather.
Of course, people tamed animals that lived round about them. It is no wonder, then, that different animals were tamed in different parts of the world. The llama and the alpaca of South America help man in the same ways as do the reindeer in the Far North and the yak in Tibet.

Kittiwake gull

   Kittiwake is the name of two species of gulls that live on open seas. Kittiwakes are about 16 or 18 inches long, and their plumage is white with gray on the back and wings. Their name is derived from their characteristic high-pitched cry, which sounds like keet, keet, wock, wock.
   The black legged kittiwake (Rissa tridactyla) inhabits arctic regions, and the red-legged kittiwake (Rissa brevirostris) lives chiefly on the Bering Sea. Both species feed on small sea animals and builds their nest on cliffs and rocky ledges. The female kittiwake usually lays two brwon spotted eggs.
   Kittiwakes are classified as order Charadriiformes, family Laridae, genus Rissa.

Black legged kittiwake

What is fluorescence?

   Fluorescence is a process in which light is emitted by atoms and molecules that have been struck by ultraviolet rays, X-rays, gamma rays, or atomic particles. The light is emitted almost instantly and does not continue after the source of rays or atomic particles is removed.

   When radiation is absorbed by an atom or molecule, the energy of the atom's or molecule's electrons is increased. The atom or molecule is in an unusual, excited state. Some of the absorbed energy is lost by collision with other atoms or molecules, and the particle cannot maintain itself in its excited state. The electrons give up their remaining unusual energy and return to their original state. The energy given up is emitted from the atom or molecule as light. The light given off is radiation of a longer wavelength than the radiation received.

   The image on a television is the result of fluorescence induced by electron bombardment. Scintillation counters, used to detect radioactivity, respond to high-energy particles or radiation because such particles cause the scintillator crystal to fluoresce.

Flowmeter

   A flowmeter is a device that measures the rate of flow of a liquid or a gas. The commonest flowmeter is called an orifice meter.
   An orifice meter is an obstruction placed in the pipe through which the liquid or gas is passing. As the liquid or gas passes the orifice, its speed is temporarily changed; as a result the pressure it exerts on the walls of the pipe is also changed. By measuring this pressure at, and on both sides of, the orifice, the rate of flow may be computed.
   Other flowmeters include the shunt meter, which directs part of the flow past a propeller, and the rotameter.

Gila monster facts

• The gila monster is an American lizard found in the deserts of Arizona and New Mexico.
• The gila monster and the Mexican beaded lizard, both of which belong to the genus Heloderma, are the only known poisonous lizards of the New World.
• The Gila monster emerges from hibernation in the first two months of the year and mates in May and June.
• The Gila monster female will lay eggs in July or August, burying them in sand 5.0 inches below the surface.
• The gila monster measures not more than 20 inches (51 cm) in length.
• Its stout, pink and black body is covered with beadlike projections rather than scales. The blunt tail serves as a storage place for fat which provides nourishment when food is scarce or unobtainable. This is evidenced by the fact that the tail becomes noticeably thinner as the animal fasts.
• Gila monsters appear to be sluggish but are surprisingly agile when annoyed. The vicious jaws fly open, a forked tongue is extruded, and the lizard hisses and snaps, endeavoring to imbed its fangs in the tormentor. Once the objective is reached, the lizard hangs on tenaciously. The venom injected is highly poison­ous and even fatal to smaller animals, such as rabbits, frogs, and mice. In spite of their viciousness, these reptiles become tame in captivity.
• Though this reptile is venomous, its laggard movement means that it poses little threat to men. 

The animal that preys in piranhas

   Piranhas glide among the submerged tree trunks of southern Guyana's flooded forests. They spread there with the rising waters that flood the river basins from March to September each year. But now, in December, the water is receding. In the area around the upper reaches of the Essequibo river, the piranhas are isolated in a string of pools. At first this was to their advantage because food was more concentrated. But now they are isolated and short of a meal. Suddenly a sleek, powerful 4 ft (1.2 m) long giant otter snatches a black piranha and crushes it with its strong teeth. The otters find piranhas easy prey to catch in the dwindling water.
   There are many types of piranha in the Amazon basin. Some are largely fruit and seed eaters, the largest up to 2 ft (610 mm) long. Others are flesh eaters 4-16 in (100-400 mm) long, including the black piranha and
the voracious red-bellied piranha. They generally eat other fish, but occasionally hunt in large groups and will tackle animals such as capybaras. With their razor-sharp triangular teeth, they shave out small semicircular chunks of flesh, which they shred and swallow. They are said to strip a victim to the bone in minutes.

Madagascar, 80 Million Years Alone

lemur

   Supposing that a group of animals—a variety of species established in the same environment—were physically isolated by some natural catastrophe from the rest of the world: would they evolve in their own fashion, to be discovered, perhaps, ages later as living relies of the past? Science fiction has toyed with this question; ecologists deal with it realistically, on islands. Madagascar, for example, 250 miles off the east coast of Africa, has been cut off from that continent for perhaps 80 million years. Since that long-ago time the island has acted as a refuge for forms of life that have become rare or extinct elsewhere. Of its plant life, for instance, 80 percent is unique to the island, found nowhere else. Chameleons originated there (opposite and Madagascar still has half of all the species known worldwide. There are also 46 genera of birds that occur nowhere else. Particularly interesting are Madagascar's lemurs, primates which elsewhere were unable to compete with their cousins, the monkeys, and so died out. Generally small in size and with considerably less developed brains than the monkeys, the lemurs throve in the isolation of their island and today their many species lead both diurnal and nocturnal lives and fill a wide variety of niches. Superstitious native tribes helped them to survive by putting the fady, or tabu, on them because they believed they once had been men.

What is a fluid?

   Matter in a state in which only equal pressure from all sides can be supported without immediate distortion is a fluid. Liquids and gases are fluids. When fluids move from place to place or change shape under inequalities of pressure, they are said to flow.

   Fluids have viscosity, or resistance to flow, because of frictional forces between molecules. Gases have smaller viscosities than liquids because the molecules of a gas are farther apart. The unit of measurement of viscosity is the poise. The viscosity of a fluid changes with temperature and pressure.

What is a fluorescent lamp?

   A fluorescent lamp is a source of artificial light produced by bombarding a phosphor with ultraviolet light. The phosphor is the heart of the lamp, for it converts shortwave ultraviolet radiation into visible light. (A phosphor, by definition, is a substance that gives off light when struck by suitable radiation, usually ultraviolet light.)
   Fluorescent lamps for household use are available in a number of different colors. Compounds of calcium, sulfur, phosphorus, and other materials are carefully mixed to produce light of daylight quality or various tints.
   A fluorescent lamp is made in the shape of a tube, the inner wall of which is coated with the phosphor. The tube is usually filled with argon, with a small amount of mercury; the amount of mercury and the pressure are adjusted to produce a considerable amount of ultraviolet radiation at 2,537 angstrom units wavelength; this is a frequency that is efficient in causing fluorescence in the phosphor materials used. At each end of the tube is an electrode. When electrons are made to flow between the electrodes by a proper voltage of electric current, the mercury vapor produces ultraviolet radiation. This radiation, in turn, makes the phosphor coating give off visible light.

Imitation

   Imitation is one of the strongest natural tendencies of the human animal. Man is more imitative than any other animal. Ani­mals which do not imitate can receive but little training and almost no education. Man acquires language, manners, morals, politics, religion, largely through imitation of those about him. The development of conscience in the child is thought to be due to imitation, to the desire to be like others and to the tendency to seek their approval. Throughout all human acquisition the tendency to imitate helps to initiate habits. After a habit becomes established the individual may or may not think of the meaning of what he does. The young man is likely to vote as his father voted. the young woman is likely to cook as her mother cooked; both legislation and diges­tion may suffer the consequences.

What is Lepidoptera?

   Lepidoptera is an order of the class Insecta, comprising the butterflies and moths. The name was given to the order because the wings are covered with little scales, or flattened hairs. The Lepidoptera undergo in their development a com­plete metamorphosis, passing through the stages of the egg, larva and pupa, before appearing as the perfect insect, or imago.

Water scorpion

   Water Scorpion is the popular name of Nepa, a genus of hemipterous insects, the species of which inhabit ponds. Some of them are powerful insects, two or three inches in length. They receive their popu­lar name from the scorpion-like form of the forelegs, with which they seize their prey.

Water scorpion

What is an incubator?

   A chicken egg in order to hatch must be kept warm. A mother hen sits on her eggs to hatch them. Her body keeps them just warm enough. But many little chickens are hatched from eggs that were kept warm in a different way. The eggs were kept warm in an incubator. Ducks and turkeys and even game birds are sometimes hatched in incubators, too.

   An incubator is a kind of oven. The first incubators were heated with oil lamps and had to be watched carefully. There was danger that they would get too warm or too cool. Most incubators today are heated with electricity. It is easy to keep them at an even temperature. For chickens, the temperature should be kept at about  102 °F. The eggs are turned from time to time so that they are heated evenly all over. The air inside the incubator must be kept fresh and moist as well as warm.

   Incubators of another kind are found in hospitals. They are for babies that are especially tiny and weak when they are born. These babies need to be kept as warm as they were when they were still in their mothers' bodies. As a rule they are soon big and strong enough to leave the incubators. Incubators, now that they are in common use in hospitals, are saving the lives of a great many babies.

Knives, forks, and spoons

   In early times even kings and queens ate with their fingers. Later, people began eating with spoons. Many years later they started using knives and forks.

   The first spoons meant for use at a table were made out of expensive metals such as gold, bronze, and silver. Because spoons were not useful in eating all kinds of food, forks were invented.

   The first forks had only two prongs. They were designed by the wife of an Italian nobleman about 1100. Forks soon became common in Italy. Then knives for use at table became common, too. The use of knives and forks spread far and wide from Italy. But in some countries, such as China and Japan, knives and forks never came to be common tools for eating. Most Chinese and Japanese still use chopsticks.

   Silver and stainless steel are the metals now most popular for "table silver." There are many beautiful patterns. Of course, knives, forks, and spoons of many sizes and shapes are found in the kitchen, too.

What is knitting?

   Thousands of years ago our ancestors learned to weave yarn into cloth. Knitting is much newer. But it is not new. It is several hundred years old. In weaving there are up-and-down threads and cross threads. Knitting can be done with a single thread.

   In knitting, yarn is looped through loops. Knitted materials are looser and more stretchy than woven materials. But they do not keep their shape as well.

   The first knitting we know about was done by fishermen's wives in Scotland. They knitted caps for their husbands. Of course, they did their knitting by hand. The finest knitted suits and sweaters and baby clothes are still knitted by hand. They are knitted on knitting needles. But most knitting is now done by machine.

   The knitting machine was invented in England in the days of Queen Elizabeth I. The inventor was William Lee. One story is that he invented the machine because the girl he loved spent too much time knitting instead of talking to him. Lee gave the Queen a pair of silk stockings he had knitted on his machine. She was pleased, but she would not give Lee a patent on the machine. She was afraid it would throw many knitters out of work.

   Knitting machines can knit yarn of many kinds. Wool, silk, rayon, and nylon are the yarns most used. All hosiery is knitted. Hosiery is knitted in the shape it is to be. So are many suits and sweaters. But yard goods also can be knitted and then cut and sewed into clothing. Tricot and jersey are both knitted materials.

Water lily (flower)

   The water lily has a fleshy tuber, or Woodstock, buried in the mud. The Tuber of some kinds is used as food because of its high starch content. The large, shield-like leaves grow under the water or floating. A single flower of great beauty is usually raised above the water. Some species bloom in the day and close their flowers at night; others bloom at night and close their blossoms in the day. The flowers range in color, though the white-flowered water lily is most common.
   The water lily grows in both temperate and tropical zones all over the world. The white, fragrant Nymphaea odorata are common in eastern North America. The yellow Nuphar advenum is common to the eastern States and Canada. Victoria regia, the giant water lily of the Amazon, grows to tremendous size, with leaves six feet in diameter and flowers 18 inches across. The lotus of Egypt, India and China comes under the general classification of water lily.

What is a water cycle?

   A water cycle is the round-trip story of a raindrop. The cycle starts in oceans, seas, and lakes. When the sun shines, the air is warmed and it acts like a sponge. The heat of the sun slowly turns the water into a gas which is called water vapor. This process is called evaporation. Warm air is lighter than cold air, thus the cold air pushes the warm air upward. As it moves upward, currents of air develop; these air motions are called winds. When the warm, moist air passes over mountains, or when these warm air masses rise high above the earth, they are cooled. Cooling causes the water vapor to condense to the liquid form.

   The raindrop is formed out of many condensed particles of water vapor. The condensations get heavier as they fall through more condensing water vapor, pulled toward the surface of the earth by gravity.

Weight

   The weight of an object is the force with which it is pulled toward the center of the earth. This force is directly related to the mass of the object, a basic characteristic of matter. It is also dependent on the distance of the object from the center of the earth.
   The pull of the earth, called the force of gravity, is slightly greater at the poles than at the equator because of the fact that the earth is flatter at the poles. The earth's surface is actually nearer its center there. This resulted from the centrifugal force of the earth's rotation. An object that weighs 300 pounds at the poles will weigh 299 pounds at the equator.
   Weight is greatest at the earth's surface. Weight decreases proportionately the farther one is above or below the surface of the earth. At an altitude of two miles, or at four miles below the earth's surface, the weight of an object would be about 0.1 per cent of its weight at the surface.
   Weight is measured in pound-weight or gram-weight. One pound-weight is defined as the weight of one pound mass at a location where the acceleration of gravity is 32.1740 feet per second squared. One gram-weight is the weight of one gram mass in a similar location. Pound- or gram-weights of materials are convenient measures of the quantity of a substance.
   The concept of weightlessness means that there is no resistance to the pull of gravity on an object.

What is a Well?

   A well is an opening in the earth which may be drilled or dug to reach water which collects underground. This collection of water is called the water table. The water may exist in basins formed of clay or various types of rock, or it may be a running stream deep in the earth. After an opening has been drilled, a pipe is lowered to reach the water. A pump is then installed at the surface to supply the power to lift the water up through the pipe. A PUMP may be operated by hand or by some other mechanical means.

   When the underground water seeps into a basin-like reservoir where hard rock layers press upon it, the water will escape or forcibly flow when the underground reservoir is tapped. This is called hydrostatic pressure and no other power is needed to bring the water to the surface. This is an artesian well.

Froghopper facts

   The froghopper, also known as Spittle Bug, is a common insect of the order Homoptera and family Cercopidae. The larvae are notable in that they produce the frothy substance called "frog spit" or "cuckoo spit" seen on shrubs, grass, and other plants during the summer. After feeding on the plant sap the larva discharges excess sap through the anus. A mucilage-like substance secreted by certain abdominal glands is added. This serves to make the sap more viscous, thereby retaining the air bubbles formed on elimination. As the froth is discharged the insect becomes surrounded and eventually completely covered, this covering constituting an ideal means of protection against enemies. Adult froghoppers, usually a fraction of an inch in size, are excellent leapers. The most common genera are Lepyronia, Aphrophora, and Clastoptera.

Goldeneye duck

   The goldeneye is a duck that visits the United States in winter, but breeds only in Canada. In the male goldeneye, Glaucionetta clangula americana, the head is glossy green, with a slight crest and white cheek patches; the front and sides of the body are mostly white and the back and tail black. An allied species, G. islandica, is abundant in Iceland and North Amer­ica, and is known as Barrow's goldeneye.

Working elephants in India

The Life of a Worker

Even today, as jets fly overhead and automobiles ply the roads, there are about 3,000 working elephants in India and nearby countries. Compared with machines, elephants seem inefficient; they require extensive training, have limited endurance and consume mountains of rice. But they can do some jobs better. Apart from hauling timber and carrying merchandise from one market center to another, elephants are now used to plow farmlands. at half the cost of operating tractors. In a few months, a mahout, assisted by tame elephants, teaches a new recruit some 30 commands which it never forgets. In return, the animal is required to labor only four hours a day and grazes free three months of the year.

Who was Hegel?

   Georg Wilhelm Friedrich Hegel (1770-1831) was a German philosopher. He was born at Stuttgart, and received an elementary education at the schools of that city. He received his degree at the University of Tubingen in 1793. For want of a more lucrative employment he acted as a tutor in a family living near Bern, Switzerland. His diary gives an account of various delightful trips afoot in that region. From Bern he made his way to Frankfurt, where he accepted a similar position in the family of a merchant. In 1799 he inherited money from his father, with which he took his way to the University of Jena, at that time perhaps the most celebrated institution of learning in Europe. Here he secured permission to lecture in return for fees, and rose speedily to the rank of professor. During the Napoleonic wars the university was impoverished and the students scattered. Hegel was forced to accept a position as the editor of an unimportant paper. In 1808 he was made rector of the gymnasium of Nuremberg—principal of the high school we should say. Here he married happily. In 1816 he was offered a professorship of philosophy at the University of Heidelberg. Two years later he accepted a similar professorship at the University of Berlin, a position which he held with renown until the time of his death. Hegel was considered a progressive, fearless thinker. His classrooms were thronged by students who spread his fame throughout Europe. He is described as having a plain, old-fashioned face, furrowed with thought. When lecturing he sat with his snuff box within convenient reach of one hand, while he turned his notes with the other. His utterance was slow. He seemed to struggle for words and at times would make little progress, yet the student needed to be constantly on his guard, lest the lecturer glide away with unexpected ease of movement and the connection be lost. He died from an attack of cholera.

What does Hegira mean?

   Hegira is an Arabic word meaning the flight or departure. More particularly it is the date of Mohammed's flight from the holy city of Mecca, 622 A. D. The Muslims reckon time from the hegira, as we do from the birth of Christ. Their dates begin 622 years behind ours. In order to change from one time to the other, it is necessary to make an additional allowance for the shortness of the Arabic year, which consists of lunar months.

Brussels Griffon

   The Brussels Griffon is a compactly built toy dog, descended from the Belgian Street dog and Affenpinscher. This alert and unusually intelligent dog has a wiry red-brown coat, fringed around the eyes, nose, chin, and cheeks. Its turned-up nose, dark eyes, and prominent chin are characteristic of the breed. Small size dogs usually weigh no more than 7 pounds and large size dogs do not exceed 11 or 12.

How does an iceberg form?

   A iceberg is a fragment of a glacier floating about in the sea. If a glacier on the coast pushes out into the sea faster than it wastes away, a mass. of ice breaks off sooner or later and floats away. The floating ice is then called an iceberg. The icebergs of the North Atlantic are formed chiefly on the shores of Greenland. Some of the blocks measure a mile or more across, and are from 1,200 to 1,500 feet in thickness. As ice is lighter than water an iceberg floats like a chip, but it should be remembered that only the small end is above water, possibly one-tenth of the bulk. An iceberg extends five or six times as far beneath the surface of the water as it does above. The warm waters which prevail along the north-western coast of Europe melt the icebergs before they drift farther south than 70° of north latitude. On the American coast they drift as far south as the banks of New-foundland. Seen in the daytime and in clear weather, icebergs are often very beautiful. Minarets and towers glitter in the sun like fairy work, but they are none the less a source of real danger to ships, especially in dark nights and amidst the fogs that prevail. As icebergs are formed on land their water is fresh and is often relied upon for use on board ship. An iceberg must be approached with caution, however, because splinters and slivers are likely to fall at any time. Although the North Pa­cific Ocean is approached by magnificent glaciers, icebergs are by no means so prominent as in the North Atlantic. The ice­bergs of the southern hemisphere, if we except the region of Cape Horn, seldom interfere with navigation.

Ichneumon (mammal)

Ichneumon (Egyptian mongoose)

  The Ichneumon is a weasel-shaped animal of tropical countries. The name is Greek, meaning the tracker. The Egyptian species is somewhat longer than a cat, but is much more slender. The ichneumon is an active, yellowish animal with black muzzle and paws. It is exceeding valuable for the destruction of the rats and mice that infest a grain-raising country, and especially for the deadly warfare it carries on with poisonous snakes. It follows along the shores, and limits the increase of the crocodile by digging up its eggs. The ichneumon is known also as Pharaoh's rat.

The smelt fish

   Smelt is a common name for fish of the genus Osmerus in the Osmeridae family, characterized by strong fanglike teeth, especially on the tongue and on the tip of the vomer, and by rather large scales, which readily fall off. The form is very troutlike, but more slender; the tail is larger in proportion, and more forked. The back is whitish, tinged with green; the upper part of the sides shows bluish tints, and the lower part of the sides and the belly are of a bright silvery color. The smelt is used extensively as a food.

Ferret

   A ferret is any of various polecats, or weasel-like mammals, native to Europe, Asia, and North America. Specifically the name refers to a domesticated variety of ferret (Mustela putorius furo), which was developed from the European polecat and which has been used for centuries to flush rats and rabbits from burrows so that hunters or dogs can kill them. Even without training, ferrets are good hunters and attack viciously. They are very quick and usually kill their prey by biting at the base of the skull.
   The domesticated ferret reaches a length of about 22 inches, including its 6-inch-long tail. It has a slender agile body, a relatively long muscular neck, and short legs. Although the animals sometimes have dark hair and eyes like polecats, most of them are yellowish white with pink eyes and a pink nose.
   A rare wild ferret, the black-footed ferret (M. nigripes), is natíve to the Great Platas and the Rocky Mountains. It grows to a length of about 2 feet, and it has yellow-brown hair and black feet.
Ferrets are classified in the order Carnivora, family Mustelidae, genus Mustela.

Insect world

   Many scientists argue that the true owners of our planet is not men, but insects, which in some respects is accurate. First, insects are probably the oldest terrestrial animals. Many species still live today, such as termites, which have existed for millions of years. Numerically, insects outnumber all land animals taken together and their total weight would be greater than all other living creatures. Many species of insects have reached perfection in the missions for which they were created. His organization is also perfect, a fact that allows them to dominate the environment in which they live. They are animals that reproduce faster and in greater numbers, before reaching the end of his life, a fly lies 400 to 900 eggs, which will be born as many insects.

Oilbirds

   Oilbird, or guacharo the type of a peculiar family, related both to the nightjars and to the frog-mouths. The guacharo, Steatomis caripensis, found in northern South America, and in Trinidad, is noc­turnal and feeds chiefly on fruits. It nests on ledges in the interior of caves near the sea, forming a heavy bowl of mud and feathers to hold its white eggs. The fat of the nestlings yields a valuable oil.

What is gramicidin?

   Gramicidin is an antibiotic effective against gram-positive bacteria. On account of its toxic effects it is not suitable for systemic administration. It is, however, highly useful in the treatment of a number of local infections in the form of impregnated adhesive compress dressings or other forms of local application. Gramicidin inhibits the growth of a large number of micro-organisms in culture media and it was found that its application to gunshot wounds, infected ulcers, and osteomyelitic lesions leads to a rapid disappearance of bacteria from the wound. Favorable results have also been reported in the treatment of middle ear and mastoid infections, sinusitis, infectious inflammation of the conjunctiva of the eye, and even in certain bladder infections. It must be emphasized that in all these cases the drug must be applied locally, e.g., by instillation into the eye or by direct application to mastoid cavities following operation. Gramicidin is too poisonous to be used by injection. Its principal toxicity consists of its destructive effect on the red blood cells, causing hemolysis.

What is a gram?

   Gram is the unit of weight in the metric system. It is the one-thousandth part of the international standard platinum-iridium prototype kilogram, and is the thousandth part of the weight of a liter of distilled water at 4 °C. In other words, it is the weight of a cubic centimeter of distilled water at this temperature. It is equal to 15.43248 grains. The subdivisions of the gram are expressed by Latin prefixes—decigram (1/10), centigram (1/100), milligram (1/1000); the multiples by Greek prefixes—decagram (10 grams), hectogram (100 grams), kilogram (1,000 grams). The kilogram is equal to about 2.2 Ibs.

What is frost?

   Frost are ice crystals formed when moisture passes directly from the gaseous to the solid state. This formation occurs when the dew point of the air is below 32 °F. The process is called sublimation. Of the two kinds of frost, one, known as light frost or hoarfrost, forms on objects that are below freezing but that are surrounded by air whose temperature remains above freezing. The other kind of frost, called hard frost or black frost, freezes and blackens plants without forming hoarfrost. Black frost is formed on objects when both their temperature and that of the air around them are below freezing.
   The first frosts in the United States occur a little before September 1. It is important for farmers and fruit growers to know when the first frost will occur. For that reason the United States Weather Bureau issues frost warnings. Forewarned of possible frost, farmers can cover their flower gardens and vegetable gardens with cloth or screens, and fruit growers can light their stoves or smudge pots.

Hog

    The hog is a domestic animal descended from the wild boar of Europe and Asia. The flesh of the hog is used universally as food, its hide is made into a good quality of leather, and the bristles are used to make brushes. The flesh, because of the quantities of salt it can absorb, is more extensively cured than is the flesh of any other animal. The Jewish and Muslim religions forbid the use of pork, stigmatizing the hog as an unclean animal. Yet the hog's fondness for mud baths is easily accounted for; the animal is a pachyderm, that is, it has a more than ordinarily thick skin, as have the hippopotamus and rhinoceros, and wet, cool mud plastered onto its hide furnishes about the only source of coolness of a constancy to insure penetration of the skin. Yet the filthy hog wallow is not essential to the animal's health; it thrives in clean sanitary surroundings as well as any other domestic animal, as hog raisers now know.

Glyptodon - some facts

   The glyptodon is an extinct mammal, fossil remains of which are found most frequently in South America, and less frequently in the United States. Living in the Tertiary period, it resembled the tortoise in structure, having an armored back and tail. Lenght, 12-14 ft.
   The glyptodon belonged to the Edentata, and resembled a gigantic armadillo. Representatives of the group are found in the Miocene, but they attained their chief development in the Pleistocene.

glyptodon

Who was Robert Frost?

   Robert Frost (1874-1963) was an American poet, born in San Francisco. While he was still a boy, his family moved to New England, where he lived for many years. Frost attended college briefly at Dartmouth and Harvard and worked at several odd jobs, since his early verse brought him very little income. In his early 20's he married Elinor White (a girl he had known in high school), took a farm in New Hampshire, and began teaching school to supplement their income. In 1912 he moved to England with his family so that he could live more cheaply and concentrate on writing. English readers welcomed his first published volumes, A Boy's Will and North of Boston. The poems "Mending Wall" and "Death of the Hired Man" both appeared in North of Boston. When Frost returned to New Hampshire with his family in 1915, he found to his surprise and delight that he had finally won recognition as an American poet. His best known poem, the "Road Not Taken," appeared a year later.

   Many of Frost's poems were written as narratives, dramatic monologues, or conversations in the plain, rather tight-lipped vernacular of the New England farmer and reflected his habit of understatement, his shrewd humor, and his sense of irony. There is also a darker side to Frost's verse, which he himself expresses in the metaphor of the "indwelling spider." Terror and violence lurk beneath a restrained, conversational surface in such poems as "The Hill Wife" and "The Bonfire."

   Robert Frost was awarded the Pulitzer prize in poetry on four different occasions. Though he never finished college, he taught in several universities in the United States and also received 40 honorary degrees from both English and American universities. Frost continued to write poetry after the publication of his Complete Poems in 1949, and he also wrote two plays in blank verse. His projected work, The Great Misgiving, includes a number of his most recent poems. In 1958 Frost was appointed consultant in poetry to the Library of Congress.

Frozen food

   Frozen food includes fruits, vegetables, meat, fish, poultry, eggs, dairy products, and cooked foods that are packaged, frozen at 0 °F. or lower, and stored at 0 °F. or lower. These products are intended for relatively long-term storage and, in most cases, will keep in storage for a year or longer without significant change. Generally, frozen products are more nearly like the fresh product in color and flavor than those preserved in any other way.

   In the United States frozen foods have been available to the public in retail-size packages since about 1945; but certain products, such as berries and eggs, have been on the market for many more years in wholesale quantities. Locker plants were in use prior to World War II. More recently home-freezer cabinets have been manufactured to provide efficient cold storage for the home processor.

What is a Projector?

  A projector is an optical device which sends out a beam of light. The projector contains a very bright source of light. This light can be gathered and directed by mirrors and lenses. The beam of light can be made to carry an image to be viewed on a screen.

  A simple projector throws an image of any small picture onto a table or other surface. A box, with ventilation holes on the sides should be big enough to hold a light bulb and the picture to be projected. The light that bounces off the picture will have a path from the box and through the projection hole.

  From all parts of the picture, bounced light gets out the hole to strike a screen. An image will show on the screen faintly but rather clearly if the hole is small, and bright but very fuzzy if the hole is large. The viewing screen cannot be very far from the box.

What is a pump?

  A pump is a machine made to raise or move liquids or gases by suction or pressure.

  Pumps serve many purposes. In rural areas, hand or electric-powered pumps lift water from a well. A pump removes water from washing machines. Pumps circulate water, gasoline, and oil within an automobile engine. Large electric pumps force water to houses in the city. Oil, gasoline, and natural gas are transported hundreds of miles through pipe lines by means of pumps. The animal heart is a very important pump.

  One of the earliest known pumps was the Egyptian "chain of pots." This pump obtained water from the Nile river. Romans used pumps in connection with their skill-fully-developed aqueduct and city water system.

The Quirks of Isolation

   Animals, like humans, develop special characteristics if they are isolated long enough on islands. Sometimes this is simply because the lack of other competitive animals gives them broader opportunities: a seed-eating bird may branch out and evolve subspecies that feed on insects, nectar or even fish. Sometimes a change in climate may result in the evolution of a new type, as in the case of a jay-sized, blue-black bird, a species of drongo, found exclusively in a wet, mountain evergreen forest in Ceylon. The difference between this drongo and its close relatives, which live in other parts of Ceylon, is that—isolated by climatic changes—it has lost the long, racket-shaped tail and head crest characteristic of the species.
   Sometimes islands even foster such curious developments as the long and flexible nose of the male proboscis monkey—an appendage which seems to have no relationship to what this animal eats or does, and is even inexplicable in terms of its rela­tives, the closest of which, in this case, probably live in China and have more normal noses. And tropical Asia, has one animal, the dragon of Komodo, which in isolation has turned into a giant—either from lack of any competition by other predators or perhaps because of a mutation of its genes which was perpetuated, unchecked, through the ages.

Nuthatch facts

   The nuthatch is a small bird. It has a long, straight bill, a short, square tail and large feet and claws. It hunts its food—insects, insect eggs or seeds—among cracks in tree bark and can walk sideways or up and down on a tree trunk or branch. Nuthatches build twig and grass nests in holes in trees.
   The red-breasted nuthatch is a small bird about four and one-half inches long. It lives in pine forests and eats pine seeds. It has a black cap and reddish-brown underparts. Its call is short and nasal sounding.
   The white-breasted nuthatch is one of the most abundant winter residents in eastern America. It has a blue-gray back and white breast. It prefers open woods to forests.
   The pygmy nuthatch, a gray bird, is a western bird, and the brown-headed nut­hatch lives in southern pine woods.

Facts about ostriches

• Order The Ostrich belongs to the ratite order Struthioniformes.
• Where found South Africa; East Africa; Sahara and adjacent Sahel region. In dry grasslands.
• Height Male about 8 ft (2.4 m); female about 6 ft (1.8 m).
• Height 140-230 lb (63-l05 kg).
• Feeding They mainly feed on seeds, shrubs, grass, fruit and flowers.
• Lifespan 30-68 years.
• Its scientific name Struthio camelus is derived from Latin, struthio meaning "Ostrich" and camelus meaning "camel", alluding to its dry habitat.
• In South Africa, the adults and the growing chicks band together in larger groups and establish a pecking order. In different localities, ostriches breed at difierent times, but often before the onset of rains so that growing birds will have enough to eat.
• The Ostrich is the world's fastest two-legged animal (43 mph).
• Their long legs enable ostriches to forage over long distances to find food plants amid sparse vegetation. In East Africa, ostriches breed during the dry season. In South Africa, the sexes separate into different flocks ready for the courtship before they disperse into nesting territories.
• In South Africa, breeding begins. A male mates with 3 or 4 females, and in the next 3 weeks each lays 4-8 eggs in one nest (a scrape in the soil) to give a clutch of about 25. The eggs are incubated for 6 weeks by the male and dominant female. About half hatch. Chicks feed themselves at once.
• Chicks are tended by the male and the dominant female; they may try to distract predators such as jackals. They also shade the chicks from the sun, and lead them to food and water. Only about 1 chick in 10 survives to be 1 year old.
• In some countries, people race each other on the back of Ostriches.

Henry Irving

   Henry Irving (1838-1905) was a celebrated English actor. His original name was John Henry Brodribb. His education was that of a London clerk. He had a fondness for reading and for attending the theater. In 1856 he appeared in a play for the first time. After attaining success in plays, now little known, he impersonated Eugene Aram and Richelieu. In 1874 he played the part of Hamlet at the Lyceum Theater, London, with such power and originality as to place himself in the front rank of English actors. Four years later he obtained a lease of the Lyceum Theater. Together with Ellen Terry he made and spent a fortune in trying to raise the taste of the British public. His favorite characters were Macbeth, Othello, Shylock, and Richard III. Irving and Miss Terry visited the United States repeatedly and were received with favor. Queen Victoria knighted Irving in 1895. Three years later the University of Cambridge gave him the honorary degree of LL.D.

Governor (speed limiter)

   A governor is a device for regulating the speed of machinery. Watt, the inventor of the steam-engine, is responsible for the governor, as well as for many other of its accessories. The regulation of the speed is either by a throttle-valve in the steam-pipe or by controlling the supply of steam to the cylinder. In general the regulation is secured by centrifugal force due to increased speed causing balls to rise against gravity or against the force of springs. A decreased speed reverses the effect. Thus may the motion of the engine remain uniform with light or heavy load. Sometimes the governor is mounted upon the spoke of the flywheel, from which by a suitable gearing the supply of steam is increased or decreased.

What is gout?

   Gout is a disease of the joints, particularly of the knees and feet. Medical authorities are uncertain as to the cause and nature of gout. It is accompanied by the accumulation of a salty acid in the afflicted joints, and causes most excruciating pain. To step on a man's gouty toe is an unpardonable offense. The disease is supposed, at least by those who do not have it, to be the result of high living, especially the drinking of wine.

What is government?

   Government is a term used to describe the different agencies by which any given community or state defines its will.
   The earliest form of government was the patriarchal. As man developed his social instincts, and began to live in communities, the family became the political unit, and the head of a family was the absolute ruler over all the members of that unit. As population increased, and social relations became more complex, a more complete political organization became necessary, and gradually three distinct types of government developed: the oligarchic, the monarchic, and democratic. An oligarchy is a government in which the ruling power is vested in the hands of a few men. Such was Athens under the eupatrids. In a monarchy, the executive power is vested in a single person, usually hereditary, whose power is either absolute or limited by a constitution. Until the first two decades of the 20th century, Russia and Turkey furnished excellent examples of absolute monarchies where the sovereign's will was law; England, on the other hand, is the best example of a limited monarchy, where the real power is not in the sovereign's hands. In a democratic government, the supreme power rests in the hands of the people, and is exercised by them directly, in which case we call it a democracy; or through representatives, when it becomes a republic. No state at the present time is a pure democracy; under the reforms of Cleisthenes, Athens was for a time a true democracy. The United States, France, and Switzerland are examples of republics.

What is grammar?

   In a broad sense, grammar is the science of the use of language. Specifically, the grammar of any language is a systematic description of the words composing that language, and of the relations of those words to each other. Orthoepy, the pronunciation of words, and orthography, the spelling of words, belong properly to grammar, but in schools and textbooks it has been found more convenient to treat them in other departments. English Grammar then, as a subject of study, consists usually of three parts; 1, The classification of words; 2. Inflection of words; 3. Syntax, or the relations of words to each other.

What is gravitation?

   Gravitation is a universal force existing in nature. The law of universal gravitation was enunciated first by Sir Isaac Newton. Every particle of matter in the universe attracts every other particle with a force proportionate to the product of their masses and inversely proportionate to the square of their distance apart. According to this principle, two masses with weights of 3 and 4 at a distance apart of 1 would attract each other with a force of 3 X 4 or 12. The same masses at a distance apart of 2 would attract each other with a force of 12 divided by the square of 2, which would give an attractive force of 3. At a distance apart of 3 they would attract each other with a force of 12 divided by the square of 3, which gives 11-3. The earth, like all moving bodies, tends to go in a straight line in whatever direction it happens to be moving. Were it not for gravitation, the path of the earth would be a straight line, and we should in time get so far from the sun that all life would be frozen. The attraction of gravity, however, draws the earth toward the sun. The two forces counteract each other. Instead of falling toward the sun or going off in a straight line, we take an intermediate direction which carries us round and round the sun ceaselessly. The fixed stars, some of which are larger that the sun even, are too far away to affect the earth's course sensibly. The earth draws the sun with a force equal to that with which the sun draws the earth, but the sun is so heavy in comparison with the weight of the earth that the sun scarcely budges, while the earth does the falling. Gravitation refers to the attraction of gravitation between the earth and bodies near its surface.

The Wizard of Menlo Park

  Thomas Alva Edison (1847-1931) The man called "The Wizard of Menlo Park" was probably the world's greatest in­ventor. He invented many wonderful things. His name was Thomas Edison.

  Edison's most famous invention was the incandescent electric lamp. In lamps of the kinds used before the days of electricity, something has to burn to make light. Kerosene is burned in a kerosene lamp, and gas is burned in a gas lamp. A candle gives off light when the wax in it burns. In an incandescent lamp something is heated white hot so that it glows. It does not burn up—at least, not for a long time.

Jerboa - some facts

   Jerboa is any of various fawn-colored, mouse-like, leaping rodents of North Africa and Asia. Thought a relative of mice and rats, and about the size of a large rat, it has long hind legs and leaps like a kangaroo.
   Perhaps the best-known species is the Lesser Egyptian Jerboa (Jaculus jaculus) which occupies some of the most hostile deserts on the planet. It does not drink at all, relying on its food to provide enough moisture for survival.

Giraffa camelopardalis

Interesting facts about the giraffe

• The Giraffe (Giraffa camelopardalis) is an even-toed African mammal belonging to the order Artiodactyla.
•  Owing to the great length of the neck and of the limbs, the giraffe is by far the tallest of mammals.
• The giraffe scientific name, refers to its camel-like face and irregular patches of color on a light background, which bear a vague resemblance to a leopard's spots.
•  In the ordinary giraffe there are two "horns," or bony prominences only a few inches in length, and covered with hairy skin; and there is, in addition, a dome-shaped protuberance between the eyes, sometimes called the third horn. 
• Some specimens occasionally have an extra pair of protuberances behind the horns and are referred to as "five-horned" giraffes. 
• The giraffe has an average weight of 1,200 kg (2,600 lb) for males and 830 kg (1,800 lb) for females.
• The paired "horns" differ from the horn cores of sheep and oxen in being at first quite separate from the bones of the skull; they are never shed, but retain throughout life their hairy covering. 
• Among other important structural peculiarities of the giraffe, there are only two toes on both fore and hind feet, and the canines as well as the incisors are absent in the upper jaw. 
• The length of neck and limbs enables the animals to browse with ease on the young shoots of high trees. 
• The bulls may reach a height of 5–6 m (16–20 ft) while the females are considerably smaller. 
• The giraffe is found in the open bush country of Africa south of the Sahara desert. It frequents regions where mimosa and similar trees grow sparingly, and there is space for the rapid flight upon which it depends for safety. 
• It drinks but seldom, and in drinking is obliged to separate the front legs sideways in order to reach the water. 
• The hoofs are large, and can be used as weapons with great force, the bulls employing them in their combats with one another after the fashion of stallions. 
• Dominant males each mate with multiple females.
• The giraffe lives in herds, with an old male as leader. Its nearest living ally is the okapi.

What is vermin?

   Vermin is a generic name given to the smaller animals that damage man's crops or other estate or prey on his domesticated animals, and insect pests such as the bed-bug, cockroach, and louse. As thus used, vermin includes the smaller mammalia and certain kinds of birds. It is unquestionable from the ranks of the quadrupeds that the great majority of vermin are drawn. Thus in gamekeeper's parlance all the weasel tribe — stoats, polecats, and weasels — are typical vermin. Hedgehogs are equally vermin in his eyes, because he believes they devour the eggs of game — a belief utterly without foundation. The destruction of hedgehogs, in fact, should be discountenanced, considering the service these ani­mals perform in removing noxious insects. Eats and mice, especially field mice and field voles, may increase in such numbers as to destroy large quantities of grain, and thus become decidedly destructive vermin, while serious loss may also be caused to the farmer by hares and rabbits as well as by rodents. Among birds, Many of the rap­tores are destructive to game. The falcons, hawks, and kites are vermin in this sense; so also are crows, owls. and magpies; but as the latter feed chiefly on mice and other small quadrupeds they are beneficial to man by repressing animals far more truly named vermin than themselves.

Gopher (Geomyidae)

   Gopher is a common name properly given to several species and varieties of animals belonging to the family of pocket gophers, Geomyidae. The name is incorrectly applied to various ground squirrels or spermophiles. The pocket or mole gopher, Geomys bursarius, is a sturdy little animal with a stout, compact body; a coat of soft silky hair, earthy brown in color, and external cheek pouches or pockets. The forefeet are armed with strong curved claws, and the upper front teeth are specially adapted for digging. The animal lives almost entirely underground, where it frequently runs its galleries to great distances, coming to the surface occasionally to throw out the loosened dirt. Once a year the male emerges to seek a mate, but for the remainder of the time the habit of life is solitary. One brood—usually of two or three young—is raised each year.

Who was Jeremiah?

   Jeremiah was one of the greater prophets of the Old Testament. He was of priestly descent, his father being Hilkiah, and he lived in Anathot, about 3 miles from Jerusalem. He became a prophet about 629 B. C., and he continued to prophesy for 41 years, during which period Judah suffered heavy disasters, and Jerusalem was made a heap of ruins by the invasions of the Babylonians. He wrote the book of Jeremiah, one of the canonical books of the Old Testament, and the Lamentations,
   Tradition says that the aged prophet was put to death in Egypt for preaching against idolatry.

Elements

   The ancient Greeks had the idea that everything on earth was made up of four simple substances—fire, air, earth, and water. A part of their idea was right. All the millions of different materials in the world are made of certain simple sub­stances. We call them elements. They can be thought of as the building blocks of the universe. But the Greeks were wrong about what the simple substances are and how many there are.

   There are a few more than 100 elements. For many years scientists felt sure that there were just 92. There are just 92 natu­ral elements. But scientists have produced several others in their laboratories.

   More than three-fourths of all the ele­ments are solids. Most of the others are gases. Carbon and iron are examples of solid elements. Oxygen and chlorine are gases. There are only two liquid elements. They are mercury and bromine.

Peri­winkles

The Last Frontier

sea snail

Pioneering barnacles and periwinkles (Littorina littorea) ordinarily cover the upper littoral. Their populations are regularly replenished by the young, which float in from the sea on the spring flood tides, often attaching themselves near established groups of adults. Occasionally barnacles settle where they will not be able to mature when the tide drops. Unable to maneuver down into a wetter environment, they die. Periwin­kles, however, are mobile creatures. Impelled by a complex gravity-overcoming mechanism to move up the beach, each species advances as far as it can without excessive drying, the rough periwinkle stopping at the limits of the seaweed and the small peri­winkle going on to reach the high spring tide mark.

What is hypochlorous acid?

   Hypochlorous acid is a weak, inorganic acid that is used as a household bleach and disinfectant. It is also used to kill bacteria in water. Both hypochlorous acid and its salts are good oxidizing agents. Neutralizing the acid gives salts called hypochlorites. Calcium hypochlorite preparations are the most widely used "hypochlorite" bleaches.
   Hypochlorous acid is the weakest chlorine acid. It exists only in water solution, and is very unstable. Even the more concentrated Solutions of the acid decompose into other chlorine acids in only a few hours. Its chemical formula is HCOl.

Hirax facts

   The hyrax lives in Africa and nearby parts of Asia. It is the "cony" of the Bible. There are a number of different kinds. Some kinds live in trees, but most kinds live among rocks in barren regions.
   A hyrax is about the size of a rabbit and looks somewhat like a guinea pig. But the hyrax is not at all closely related to either of these two animals. It is more closely related to the elephant and the sea cow, but it is not a close relative of either. The hyrax really has no close relatives at all.
   This small animal is a plant eater. It eats leaves and young branches of plants. During the day it rests. At dusk it starts hunting for food.
   In a hyrax family there are usually from three to six babies. They are as playful as kittens. Many hyrax families live together in big communities just as prairie dogs do.
   In one way a hyrax is like a skunk. It sends out a strong odor if it is disturbed.