英语知识精华文章

Diamonds in the United States

Most of the world's diamonds come from Africa，but there is one place in the United States where they are found．It is near Murfreesboro，Arkansas．

Diamonds were first found near Murfreesboro in 1906．About fifty thousand diamonds have come from this field．One forty－caratdiamond was the largest ever found in North America．But most of the stones were too small to make mining worthwhile．Soon all mining stopped there．Today a visitor to Murfreesboro can hurt for diamonds himself．

A few diamonds have been found in sand and gravel along the Great Lakes，too．But none of these were in their original blue ground．They may have been formed far to the north and carried south by the last great glaciers．

The Necktie through Thick and Thin

From hat to shoes，men's clothes are useful．Only one piece of clothing is worn just for decoration．It is the necktie，or cravat．The necktie is left over from the time when men wore ruffles，ribbons，and tassels．

Beau Brummel was an Englishman of the early 1800's．He was famous for his fancy clothes．The story is told that he used to invite guests just to watch him knot his white cravat．

Now，perhaps，even the necktie is going out of style．It has been getting smaller and smaller for hundreds of years．It started out as a piece of lace and turned into a silk bow．Then it became a triangle that was tied around the neck．Now many neckties are no wider than a piece of string．

Who First Made Ice Cream

Most Americans think that ice cream is as American as baseball and apple pie．But ice cream was known long before America was discovered．

The Roman emperor Nero may have made a kind of ice cream．He hired hundreds of men to bring snow and ice from the mountains．He used it to make cold drinks．Traveler Marco Polobrought back recipes for chilled and frozen milk from China．

Hundreds of years later，ice cream reached England．It is said that King Charles Ienjoyed that treatvery much．There is a story that he bribed his cook to keep the recipe for ice cream a royal secret．

Today ice cream is known throughout the world．Americans alone eat more than two billion quartsa year．

Earthworms that Help Improve the Soil

The earthworm is a useful animal．Out of the ground，it is food for other animals．In the ground，it makes rich soil for fields and gardens．

Earthworms dig tunnels that loosen the soil and make it easy for air and water to reach the roots of plants．These tunnels help keep the soil well drained．

Earthworms drag dead leaves，grass，and flowers into their burrows．When this plant material decays，it makes the soil more fertile．

No other animal is so useful in building up good topsoil．It is estimated that in one year fifty thousand earthworms carry about eighteen tons of fine soil to the surface of an acre of land．One worm may add three quarters of a pound of earth to tho topsoil．

The Three Ways of Man to Preserve Meat

Finding enough meat was a problem for primitive man．Keeping it for times when it was scarce was just as hard．Three ways were found to keep meat from spoiling：salting，drying，and freezing．

People near salty waters salted their meat．At first they probably rubbed dry salt on it，but this preserved only the outside．Later they may have pickled their meat by soaking it in salt water．

In hot，dry lands，men found that they could eat meat that had dried while it was still on the bones．They later learned to cut meat into thin strips and hang it up to dry in the hot air．

Men in cold climates found that frozen meat did not spoil．They could leave their meat outside and eat it when they pleased．

How the Hawaiian Is lands Were Built

Volcanoes have been erupting on the earth for millions of years．More than five hundred still erupt today．These are called active volcanoes．Volcanoes are located in belts or chains．They are found where the earth's crust is weak．The weak spots let the hot rock escape when the volcano erupts．

Many volcano belts are mountain ranges along the edges of continents．One belt runs along the western coast of South America up through the western part of the United States．Other volcanoes are found in ocean basins．

About three－fifths of all active volcanoes in the world are in the Pacific Ocean．Many of these volcanoes erupt under the water．The Hawaiian Islands were built by volcanoes that began erupting under water and finally reached the surface of the ocean．

A Giraffe that Did Not Believe in Himself

In Africa I heard a story about a giraffe that did not believe in himself．

The giraffe's mother bad left him when he was a few days old because she couldn't feed him． For three years he lived in the warden's house and played with the children．Then he grew too large for the house．

The family decided that he should return to his fellows．They took him to join a herd of wild giraffes．

One look was enough for the giraffe's small brain．He could not believe that such extraordinary animals existed．Or that he was one of them！He turned and bolted．

The family took him back several times．In the end they gave up．Now their giraffe lives by himself near the warden's house．

The Antarctic，a Desert of Ice All Year Round

The antarctic is actually a desert．It is the only continent on the earth without a river or a lake．

The antarctic is all ice all year round．The warmest temperature ever recorded there is zero，at the South Pole．Explorers used to think that a place so cold would have a heavy snow－fall．But less than ten inches of snow falls each year．That is less than half an inch of water．Ten times that much moisture falls in parts of the Sahara．

The little snow that falls in Antarctica never melts．It continues to pile up deeper and deeper year after year and century after century．When the snow gets to be about eighty feet deep it is turned to ice by the weight of the snow above it．

Sen Otters off the Coast of California

sea otters off the coast of Californiahave an unusual method of getting food．They dive to the floor of the sea to find the shell－fish they like．

When an otter brings a shellfish to the surface of the water，he floats on his back and puts the shellfish on his chest．Then the otter digs the meat out of the shell with his teeth．

Sea otters are especially fond of shellfish with a very hard shell．When the otter brings up one of these，he also brings a stone．He puts the stone on his chest，holding the shellfish in his front paws．He takes a wide swing and smashes the hard shell on the stone．Then he has no trouble getting at the meat in the shell．

A Temperature Change on the Moon

Astronomers can tell just how hot the surface of the moon gets．The side of the moon toward the sun gets two degrees hotter than boiling water．The night side reaches 243 degrees below zero．

In an eclipse，the earth's shadow falls on the moon．Then the moon's temperature may drop 300 degrees in a very short time．

A temperature change like this cannot happen on the earth．Why does it happen on the moon？Astronomers think that the surface of the moon is dust．On the earth，rocks store heat from the sun．When the sun goes down，the rocks stay warm．But the dust of the moon cannot store heat．So when the moon gets dark k，the heat escapes quickly．The moon gets very cold．

How the Falls of Iguassu Was Discovered

In 1542，Alvar Cabeza de Vaca and his small band of soldiers guided their boats down a jungle river．It was the Iguassu，which now marks the boundary between Brazil and Argentina．Never had the explorers seen a river so beautiful．

At one point the men heard a strange rumble in the distance．It grew louder as they went on．Puzzled and afraid，they rounded a bend．Directly ahead of them the river vanished，plunging with a roar over the brink of a great chasm．

The men fought the swift current and managed to reach shore just in time to keep from being swept over the brink．Then they crept out on the wet rocks and looked into the churning caldron below．They had discovered the greatest waterfall that had ever been seen by white men－the falls of Iguassu．

The Hognose Snake，One of Nature's Clowns

The hognose snake，sometimes called the puff adder，is one of nature's clowns．Some people think that he is deadly poisonous．Actually，he's just a harmless fellow who spends most of his time huntingtoads．

The puff adder gets his name from being a terrific bluffer．He will swell up，hiss，and strike viciously to frighten you away．If that doesn't work，he will flatten out，making his head look like a cobra's．

He has one more trick——playing dead．He goes limp，opens his mouth wide，and rolls over on his back so that he couldn't possibly look more dead．

Unfortunately，this trick is spoiled by his one—track mind．If you pick him up he lies still．But turn him over and he will thrash about wildly，trying to turn himself belly up again．

A Tornado that Makes Red Rain

A tornado can do a lot of damage The wind of a tornado rushes at great speed around a funnel—shaped cloud．It travels in a path a few hundred feet wide and about twenty－five miles long．As the wind circles counterclockwise，the funnel spirals higher and higher．The force of the wind sucks up water，dirt，and objects，and carries them along with it．It may drop them again many miles away．Houses and huge trees have been drawn into tornado funnels．At sea，ships have been nearly sunk by tornadoes dropping water on them．

East of Australia，people talk about a“rain of blood”．This is caused by a tornado picking up red dust and mixing it with water to make red rain．There are even stories abut a rain of fish and frogs caused by a tornado sucking them up and then dropping them．

If George Washington Could Visit the United States Now

If George Washington were able to travel back and forth in time，he would feel much more at home in ancient Babylon，3700 years before his time，than in our modern age，200years after he lived．

Torches，chairots，and rough streets，like those of Babylon in 2060 B．C．，would not surprise him．He read by candlelight and rode in carriages on unpaved roads．He never saw a building more than four stories high．Electric lights，autos，high－ways，and skyscrapers would amaze him．

When Washington was ill，he might have expected to be cut and bled to let out the“bad blood”that was making him sick．He would not know what a modern doctor meant by serums，germs，and allergies．

If the Father of His Gountry could visit the United States now，he might think that he had landed on another planet！

Licorice Good for Both Man and Beast

Licorice can be used for other things besides candy．Some of the powers of the licorice plant have been known since ancient times．The Egyptians used it to cure sore throats，and an old Chinese story tells how licorice cured a dragon whose throat was sore from breathing fire．The armies of Alexander the Greatcartied licorice root as medicine on all of their campaigns．

Modern medicine uses this old knowledge．Many of today's cough sirups contain licorice．It is good for both man and beast，and veterinarians give it to horses，cattle，sheep，dogs and cats．

Licorice can put out fires，too．After the sweet juices have been taken out，the waste fiber of the root is used to make a fire——fighting foam．This foam smothers fire by keeping oxygen away from it．A licorice fire extinguisher is sold today．

The Moldy Hardtack and the Hunyry Soldiers

Hardtack，hardtack，come again no more！Union soldiers sang this song during the Givil War，and they had reason to complain．Hardtack was a plain flour－and－water biscuit．These biscuits were hard——it sometimes took a strong blow of the fist to break them．Soaking only made them rubbery．

Many times the hardtack was not fit to eat．It often became wet or moldy when it was stored．Sometimes it was full of maggots and weevils．When a soldier got a moldy biscuit，he could ask for another．But if he got a wormy one，he had to eat it abtwat or go without．

There were a few good things about hardtack．When it was eaten in the dark，no one knew whether it had bugs in it or not And there was always more for any soldier who was really bungry！

Where Did the New Life Come from

In 1883 a small volcanic island blew up．It was Krakatoa，west of Java in Sunda Strait．Nothing was left alive except one kind of earthworm．Yet in time plants began to grow again．By 1928 many kinds of animals lived on the island．

Where did the new life come from？The nearest land was almost twelve miles away．Only a few of the new animals could fly or swim so far．The bugs，flies，and spiders were probably carried by the wind．The lizards and rats may have floated there on pieces of driftwood．Snails could have come on the wind or on floating coconuts or driftwood．Tornadoes and hurricanes may also have picked up creatures and dropped them miles away．

These are some examples of“accidental migration”．Such trips have carried many plants and animals to new homes．

How a Hunter Captures a Monkey

Few animals other than monkeys have hand like paws．The monkey，like man，has an opposable thumb——that is，it can place its thumb opposite its other fingers．By pressing its first finger against its thumb a monkey can pick up things as tiny as a flea．Because other animals lack this thumb，it is difficult for them to pick up small things and carry them．

The monkey's ability to grasp rice with its paw often leads to its capture．Hunters bait a coconut with a handful of rice，leaving a hole in the shell of the nut．The monkey has no trouble sliding its paw through the hole．But it can't draw the paw out while it is holding a fistful of rice．

Since it is often too stupid or greedy to open its hand，the monkey is unable to free itself from this simple trap．

The First English Window

The first English window was just a slit in the wall．It was cut long，so that it would let in as much light as possible，and narrow，to keep out the bad weather．However，the slit let in more wind than light．This is why it was called“the wind's eye”．The word window itself comes from two Old Norse words for wind and eye．

Before windows were used，the ancient halls and castles of northern Europe and Britain were dark and smoky．Their great rooms were high，with only a hole in the roof to let out the smoke from torches and cooking fires．

As time went on，people wanted more light and air in their homes．They made the wind's eyes wider so as to admit air and light．They stretched canvas or tapestry across them to keep out the weather．

Climbing Out of a Space ship onto the surface of the Moon

We have just climbed out of a spaceship onto the surface of the moon．Behind us is the ship，half in the sunlight and half in deep shadow．A few miles ahead is a wall of mountains towering against the black sky． And there，as though resting on the mountains，is a great ball of light，beautifully colored in blue and green and brown with a patch of dazzling white at the top．It is our own faraway world——the earth．

We take a step and rise like prize jumpers－up，float，and down again．Hopping carefully，we explore the valleys，the sloping crater walls，the shadowy crater floors．

Not a sound can be heard——there is no air to carry sound，no wind；there are no smells，no plants，no animals，There is nothing but rock and dust，blinding sunlight and cold black shadows．

The Egyptians First Played Ball Games

The first true piece of sports equipment that man invented was the ball．

In ancient Egypt，as everywhere，pitching stones was a favorite children's game．But a badly thrown rock could hurt a child．Looking for something less dangerous to throw，the Egyptians made what were probably the first balls．

At first balls were made of grass or leaves held together by vines．Later they were made of pieces of animal skin sewed together and stuffed with feathers or hay．

Even though the Egyptians were warlike，they found time for peaceful games．Before long they had developed a number of ballgames，each with its own set of rules．Perhaps they played ball more for instruction than for fun．Ball playing was thought of mainly as a way to teach young men the speed and skill they would need for war．

Iceberg Season of Newfoundland and the Steamship Titanic

Each year about four hundred icebergs survive the long journey from Greenland and Baffin Bay and float into the warm waters off the coast of Newfoundland．

In April 1912 the steamship Titanic struck one of these icebergs．It sank with a great loss of life．Shortly after，the Ice Patrol was founded to patrol the shipping lane near Newfound－land during the iceberg season．

The patrol is carried out by one or two U．S．Coast Guard boats．They locate and chart every iceberg in the waters and the information is radioed to nearby ships．Fourteen nations pay the costs of the patrol service．

Icebergs begin to threaten shipping in March．It is in May that the patrol boats are busiest．During that month an average of 130 icebergs must be located and charted．By June the danger is over．

Copper，the First Metal that Man Learned to Make

Copper was the first metal that man learned to make．In some mountainous lands there were rocks streaked with green minerals．One day some rocks were accidentally heated by a roaring fire．When the fire burned low，little beads of copper were seen on the rock wall．

After that，men heated the rock deliberately to see whether more copper would appear．They soon found a good way to make copper．They would build a trench on a hillside and fill it with charcoal and copper－bearing rock．They covered this furnace with flat stones．

They started a wood fire to heat the charcoal and the hot charcoal released copper from the rock．A hot red pool of melted metal formed at the mouth of the trench．When it was cool，the solid metal could be lifted out and cut and pounded into shapes．

How Americans Showed Their Respect for Edison

Thomas Alva Edison was awarded more patents on inventions than any other American．When he died in 1931，Americans wondered how they could best show their respect for him．

One suggestion was that the nation observe a minute or two of total blackout．All electric power would be shut off in homes，streets，and factories．

Perhaps this suggested plan made Americans realize fully what Edison and his inventions meant to them．Electric power was too important to the country．Shutting if off for even a short time would have led to complete confusion．A blackout was out of the question．

On the day of Edison's funeral，many people silently dimmed their lights．In this way they honored the man who had done more than anyone else to put the great force of electricity at his countrymen's fingertips．

A Large Lake of Asphalt on the Is-land of Trinidad

At the village off La Brea，on the island of Trinidad，in the West Indies，is a large lake of asphalt called Pitch Lake．

The asphalt is hard and is dug out with a big scoop shovel or a pick，leaving a hole in the surface of the lake．Within a week or two the hole is filled with new asphalt that pushes up from below．The supply of asphalt seems to be endless．

An ancient legend explains how Pitch Lake came to be：Many centuries ago two Indian tribes fought a great battle．The victorious tribe built a village and held a victory celebration，They killed hundreds of beautiful hummingbirds，ate them，and used their feathers to decorate their clothing．The Great Spirit was so angered that the birds had been killed that he caused the entire village to sink into the earth．The crater where the village stood has been filled wish asphalt ever since．

A Large Lake of Asphalt on the Is-land of Trinidad

At the village off La Brea，on the island of Trinidad，in the West Indies，is a large lake of asphalt called Pitch Lake．

The asphalt is hard and is dug out with a big scoop shovel or a pick，leaving a hole in the surface of the lake．Within a week or two the hole is filled with new asphalt that pushes up from below．The supply of asphalt seems to be endless．

An ancient legend explains how Pitch Lake came to be：Many centuries ago two Indian tribes fought a great battle．The victorious tribe built a village and held a victory celebration，They killed hundreds of beautiful hummingbirds，ate them，and used their feathers to decorate their clothing．The Great Spirit was so angered that the birds had been killed that he caused the entire village to sink into the earth．The crater where the village stood has been filled wish asphalt ever since．

Man's First Real Invention

Man's first real invention，and one of the most important inventions in history，was the wheel．All transportation and every machine in the world depend on it．

The wheel is the simplest yet perhaps the most remarkable of all inventions，because there are no wheels in nature-no living thing was ever created with wheels．How，then，did man come to invent the wheel？

Perhaps some early hunters found that they could roll the carcass of a heavy animal through the forest on logs more easily than they could carry it．However，the logs themselves weighed a lot．

It must have taken a great prehistoric thinker to imagine two thin slices of log connected at their centers by a strong stick．This would roll along just as the logs did，yet be much lighter and easier to handle．Thus the wheel and axle came into being，and with them the first carts．

An Old Legend about Cheese

No one knows who made the first cheese，but an old leqend says that it was an Arabian merchant．He put his milk in a pouch made from a sheep's stomach and set off across the desert．The jouncing of his camel，the desert heat，and the chemicals in the pouch lining made the milk separate into curds and whey．The thick part，or curd，was the first cheese．

Ancient records show that cheese has been eaten for more than four thousand years．From earliest times it has been considered a very nourishing food．Americans eat less cheese than people in some countries do，yet they still consume eight to ten pounds a year per person．

Today cheese is made all over the world．Most cheese is made from cow's milk，because the suppply of this milk is greater throughout the world．Smaller quantities come from the milk of other animals—goats，sheep，camels，and even reindeer．

Strong and Gentle Shetlands

When is a horse a pony？

Horses are measured in hands：one hand equals 4 inches．The height of a horse is measured from the ground to the highest point of the withers（the part of a horse's back between its shoulder blades）．Any horse under 14 hands 2 inches（58inches）is a pony．

By this definition，a baby horse is not a pony；baby horses are called foals．Horses that do not develop to roughly the same size as the rest of their breed are not ponies either．Underdeveloped horses are called runts．

There are more than twenty breeds of ponies in the world．The bestknown are the Shetlands，the smallest of all breeds，which average a little less than 10 hands，about 39 inches．

Shetlands were first used in England as work animals in coal mines，because they were strong．They are also gentle，and may be trained to be good pets．

Hancock's Signature

Because he wrote his name so that it could be read easily，John Hancock has a place in the dictionary．

John Hancock was a wealthy man who helped the patriots in the American Revolution．He was president of the Continental Congress．He was also governor of Massa-chusettsand one of the first men to sign the Declaration of Independence．Yet he is remembered best for his large signature．

The story is told that when Hancock sat down to sign the Declaration of Independence，he said that he would write his signature large enough for John Bull to read without his glasses．（John Bull stands for England，as Uncle Sam stands for the United States．）Hancock's signature on the Declaration is four and three-quarters inches long——an inch longer than his usual signature．

Today John Hancock can be used to mean any person's signature．