Accomplishments

In the city of Marrakesh, Morocco, there’s a 220-foot tower that’s more unusual for its appeal to the nose than to the eye! This tower, the Koutoubiya minaret, gives off a fragrance that seems to come right out of its walls. And that’s exactly where it does come from. When the minaret was built in … Read more

The Saturn V rocket, which carried the first men to land on the moon, was as tall as a 35-story building. This rocket was built inside an assembly building so big that it could fit several of these huge rockets in an upright position! This structure, called the Vertical Assembly Building, or the VAB, is … Read more

In 1290, an Indian rajah decided to build a fortress near the city of Poona. But his engineers told him that the site of the planned fortress was so swampy that the building would sink into the ground. Then the rajah had a dream. In his dream, the gateway of the fortress was built on … Read more

When you take pictures with an ordinary camera, you must send the film away to a laboratory to have it made into photographs. But the “instant” camera makes pictures right inside the camera itself. Black-and-white “instant” film consists of two sheets of paper. One is the negative, and one is the positive. After the picture … Read more

All photographic film contains silver. Silver is very sensitive to light, and compounds that contain silver will darken when they’re exposed to light. A piece of photographic film actually consists of thousands of tiny dots of silver compounds. When the film is exposed to light, as when a camera lens opens to take a picture, … Read more

Have you ever stopped to count the number of cars in a passing railroad train? If the train was a very long freight train, you may have counted more than 100 cars. But you would have to count for a long time to reach the number the cars in the longest railroad train of all … Read more

That depends on what you mean by “largest.” The world’s longest subway is in London, stretching 255 miles, but only 101 miles are underground. The New York City subway is shorter, 231 miles long, but 134 miles of it are underground. New York’s subway is the world’s busiest. The London subway handles about 600 million … Read more

The answer could be yes . . . and it could be no. It all depends on what you mean by “circling the earth.” Magellan was the first person to sail completely around the world, but not in one voyage. Ferdinand Magellan was a Portuguese nobleman. He sailed to the East Indies with the Portuguese … Read more

Many of the tales told about medieval traveler Marco Polo were just legends. But Marco Polo did live, and he stands along with Columbus and Magellan as one of the most important explorers in history. Marco Polo came from a family of traders in Venice, Italy. When Marco was still a boy, his father met … Read more

The Pyramid of Cheops in Egypt is the world’s tallest pyramid, at a height of what was once 480 feet. This ancient pyramid covers an area of 13 acres. But there’s a pyramid in Mexico that’s even bigger! Called the Quetzalcoatl, this gigantic pyramid near Mexico City was built of sun-dried bricks and earth around … Read more

The largest ship the world has ever seen is not a passenger liner or a battleship, but an oil tanker! The largest of the huge oil-carrying ships, called supertankers, is a French vessel that weighs more than half a million tons. The ship, the Pierre Guillaumat, is 1,359 feet long, more than a quarter of … Read more

Well, they did and they didn’t. During the days of the Roman Empire, the city of Rome was supplied with water by means of aqueducts, water-carrying pipes mounted on pillars or buried underground. Aqueducts brought water from nearby mountains to public water fountains in the city, and most Romans got their water from these fountains. … Read more

In an artesian well, water rises from the ground on its own, without need of a pump. The name comes from Artois, an area of France where this kind of well was first used. The Latin name for this region was Artesium. Rainwater that soaks into the ground sinks into the earth until it reaches … Read more

A century or so ago, boxing matches had no time limit. A fight continued until one of the boxers was knocked out or gave up. The first boxing match with three minute rounds wasn’t fought until 1872, in England, and the first heavyweight championship bout fought with gloves and three minute rounds didn’t take place … Read more

In 1946, a crowd gathered in Lewiston, Maine, to watch a boxing match between Ralph Walton and Al Couture. When the bell rang to begin the first round, Couture dashed across the ring and swung at Walton before Walton had left his corner. The blow knocked Walton down, and he was counted out. The entire … Read more

On July 18, 1938, an American pilot named Douglas Corrigan took off from New York on a flight that was supposed to take him to Los Angeles, California. But Corrigan made one mistake, he went in the wrong direction, east instead of west. The next day, he landed in Dublin, Ireland, almost 6,000 miles away … Read more

In 1957, three U.S. Air Force jets took off from an airport in California, flew around the earth, and returned to the same airport from which they had taken off. The entire flight took just 45, hours and 19 minutes, making it the shortest round-the world flight in history. The total distance each of the … Read more

The Boeing 747 was the biggest jetliner in the world in 1969, when it first flew. This huge passenger jet was a little more than 231 feet long, with a distance of 195 feet from the tip of one wing to the tip of the other. The 747 could carry 500 passengers, more than any … Read more

The national airline of the Soviet Union, Aeroflot, which is owned by the Russian government, is now the largest airline in the world. Aeroflot has 1,300 planes and 400,000 workers, and carries about 90 million passengers a year to 65 different countries. The largest airline in the U.S., and the world’s largest airline not owned … Read more

A supersonic jet is a plane that can fly faster than the speed of sound, which is 660 miles per, hour at the height that jets fly. The best-known supersonic jetliner in the world is the Concorde, which was built by French and English companies together. The Concorde carries 128 passengers, and can reach speeds … Read more

The corks you find sealing up bottles come from the bark of the cork oak, which grows in Spain, Portugal, and North Africa. This bark contains a waxy substance that keeps gases and liquids from passing through the wood. About half of every cork is made up of empty space. A piece of cork just … Read more

In 1861, a doctor named Joseph Lister became a surgeon at a hospital in Glascow, Scotland. At that time, many patients who underwent surgery later developed infections that resulted in death or the loss of a limb. But no one knew why. Then Lister read an article written by French scientist Louis Pasteur, in which … Read more

Penicillin is one of the most important medical discoveries of our time, for it allows doctors to easily treat illnesses and infections that once killed many people. If it weren’t for penicillin and other drugs like it, there would be little a doctor could do for you if you came down with a very bad … Read more

Most cars on the road today are powered by an internal combustion engine. This engine contains a number of hollow chambers, called cylinders, and each chamber has a large metal plug, a piston, that moves up and down in its cylinder. Gasoline and air mix in the cylinder. As a piston moves upward in its … Read more

In 1930, two men took off from New York City and drove all the way to Los Angeles, almost 3,600 miles away, in a Ford Model A roadster. And they completed the entire trip without turning off the car once! Then they turned around and drove all the way back to New York, again without … Read more

If by automobile we mean a car powered by a piston engine, then the fastest any car has ever traveled was 4181/2 miles per hour. This speed was achieved in 1965 by a specially built car driven over the Great Salt Desert in Utah. The fastest racing car was a Porsche that reached a speed … Read more

The leather used in making shoes, handbags, belts, gloves wallets, and many kinds of clothing, furniture, and sports equipment is really the skin of animals. Usually it is taken from the hide of cattle, but pigs, sheep, goats, and calves are also used. This skin goes through several processes before it is ready to be … Read more

An air conditioner controls more than temperature indoors. It also controls the amount of moisture, movement, and purity of the air. We have come to depend on air conditioning systems to keep us comfortable during the summer months. The machine used in air conditioning works very much like the one in a kitchen refrigerator. Both … Read more

To understand the way a telephone works, we must first understand the way we hear. Anything that vibrates, or moves back and forth, sends out sound waves. These waves travel to our eardrums, which vibrate in step with the sound waves. When you speak into the mouthpiece of a phone, your voice makes sound waves. … Read more

When you watch a movie, what you actually see are many still pictures flashing by quickly. This is true of TV as well. Many still pictures are broadcast from the station, and they appear on your set so fast that they seem to be moving. But these pictures are not sent out and picked up … Read more

At the radio studio, the sound waves of a program go into a microphone that has electrical current running through it. These sound waves create vibrations in the current as they travel through wires to a control room. There, technicians control their volume and send them out through a transmitter. An antenna on the transmitter … Read more

Vibrations of sound waves, which make it possible for you to hear sounds, also make the manufacture of records possible. When a modern recording is made, sound is directed into a microphone by a voice or musical instruments. Inside the microphone the sound is converted into electric current. Then electron tubes amplify, or enlarge, this … Read more

X-rays are really like ordinary light rays, except for one thing, they have a much shorter wave length. Because of this, the ray has more energy and will be more penetrating than an ordinary light ray, even going through such solid substances as wood, metal, and concrete. An X-ray machine has high-voltage electric current flowing … Read more

A rare colorless, odorless gas was discovered in the atmosphere in 1898 by two British chemists, Sir William Ramsay and Morris W. Travers. They named it neon, which is the Greek word for “new.” Neon is found not only in our atmosphere, but also in gases trapped in the earth. Since neon is a first-rate … Read more

Every modern home has several switches in every room to stop and start the flow of electricity. Just think how troublesome life would be without them. If we had no switches, we would have to either keep our radios, TVs, stereos, and lights on all the time, or pull the plug from the socket whenever … Read more

Electricity is all about us, but in order to be useful, it must be directed into a steady flow called an electric current. In a flashlight, the electric current is produced by a dry cell battery. A battery is a unit that stores an electrical charge and is able to furnish current. It consists of … Read more

Electricity comes into our homes, schools, factories, and stores on copper or aluminum wires from powerful’ generators in power stations. These power stations burn coal or oil, or use nuclear reactors or the power of falling water to produce the energy to run the generators. Powerful loads of current come from these generators and are … Read more

Actually, you can’t see the light that is immediately given off in the long, narrow tubes of a fluorescent lamp as you can in an electric light bulb, where the glowing tungsten wire lights up the surrounding area. For in a fluorescent lamp, the light comes from a special gas called mercury vapor. When electricity … Read more

When you turn your lamp on, the electricity travels from the electric company’s generator through wires into your house. Since your lamp is plugged into an electric outlet, the electricity flows along lead-in wires to the bulb, first through the screw-in base of the bulb, around the bulb through the filament, and down into a … Read more

Paper may be made from rags, rope, straw, grass, and wastepaper, but the most common source of paper, by far, is wood. Wood from trees is taken to a paper mill, where it is cut into chips. These chips are put into huge vats, where they are boiled and stirred with chemicals until they become … Read more

When you pour hot water on gelatin powder to make a dessert, the powder seems to disappear. But it doesn’t really. It’s still there, but you can’t see it. What has happened is that the hot water breaks up the powder into tiny particles with a string-like shape. These particles are so tiny that you … Read more

A famous building stands on the corner of Wall and Broad Streets in New York City. It is the New York Stock Exchange, a very busy place from 10:00 A.M. to 4:00 P.M., Monday through Friday. This is where the stocks of the best-known corporations are bought and sold every day. The trading room is … Read more

If you invented a new kind of skateboard and wanted to go into the business of manufacturing it, that might take more money than you have. One way to raise the funds for buying a factory, ordering materials, and paying labor would be to form a corporation and inviting other people, called investors, to buy … Read more

A magnet is a metal that can pull pieces of iron toward itself and make them cling to it. A horseshoe magnet pointed at a clip will make it jump up from a table and cling to the magnet until it is pulled off. The horseshoe magnet has two poles, or ends, a positive and … Read more

The principle that explains refrigeration is that the faster a liquid evaporates, or becomes a gas, the faster it cools whatever it touches. And the liquid that evaporates rapidly enough to make water freeze is Freon 12, which is used in most electric refrigerators today. Here’s how it works. Freon 12 starts out as a … Read more

Glue, like paste or cement, joins things together. These materials are known as adhesives because they make things adhere, or stick together. Stickiness, however, is not all that it takes. In order for an adhesive to be practical, it must change from a soft liquid to a hard solid within a short period of time. … Read more

When countries were becoming industrialized in the early 1800s, the need for moving machinery and goods in factories and warehouses grew. It was then that the hydraulic elevator was invented. The hydraulic elevator used water, a plunger, and valves to raise and lower a platform in a cylinder-shaped shaft. This shaft had to be as … Read more

Even though you might think that there was no need for elevators before high-rise office and apartment buildings were built, the idea of vertical, or up and down, transportation has been in the mind of man for more than 2,000 years. Archeologists have discovered vertical shafts in the ruins of ancient civilizations. It is possible … Read more

Man has been building dams since ancient times to provide a supply of water for himself and his crops during dry seasons. These early dams were made of brush, rocks, and earth, and did not last. Today’s concrete dams however, are truly amazing feats of engineering skill. The techniques of modern dam building began in … Read more

The escalator, or moving stairs, you see in department stores, airports, and railway stations all work on the same principle, an endless belt moving around wheels. The stairs are attached to two side belts or to one central belt, which is driven by electricity. The moving handrails on both sides of the escalator work the … Read more

Have you ever decorated your skin with a colored decal from a bubble gum wrapper? If so, you know it soon washes off, because it is only on the surface of the top layer of skin. Tattoos, however, are body decorations that do not wash off. They are permanent designs on the body because their … Read more

Salt is a mineral that can be found both in liquid or solid form. It can be found in oceans, lakes, or rock beds buried deep in the earth. Where salt comes from is the key to how it is made. Salt from oceans and lakes can be produced by letting shallow holes of water … Read more

The tiny, rounded, colorless one-celled plant called yeast floats through the air everywhere, but it is responsible for making all our cakes and breads rise to a nice, fluffy texture. This happens because yeast creates chemical reactions on the starch and sugar in the cake or bread batter. Here’s how it works. Yeast cells reproduce … Read more

A periscope is built like and works much like a telescope, with a long tube containing a mirror at each end. The mirrors are fitted into the tube so that they are parallel to each other at a 45° angle to the axis, or imaginary long center line, of the tube. More complicated periscopes have … Read more

There are thousands of varieties of cheese manufactured in the world today, but all cheese starts with milk. Fresh milk is allowed to stand until it sours and lumpy curds develop. Then rennet, or digestive juices, is taken from the stomachs of young animals and is added to the lumpy curds. This separates the curds … Read more

Communications satellites launched by giant rockets have been orbiting the earth since the 1960s. Aboard each satellite is a radio receiver to receive signals from the earth, an amplifier to strengthen these signals, and a transmitter to send them back to earth. All this electronic equipment is run by solar batteries, or batteries powered by … Read more

Ancient man probably measured time by daylight and darkness, or by the rising and setting of the sun. He also probably noticed that as the earth turned, the sun was directly over his head only once a day, in the middle of the day. This he called midday. But this midday time was different in … Read more

A barometer is an instrument that measures air pressure. It uses mercury, which reacts to air pressure just as it reacts to temperature in a thermometer, by rising or falling in a glass tube. Perhaps you’re wondering why it is important to know something about air pressure. The answer is that it is an important … Read more

Sound travels in waves, much the same way ripples of water travel in the ocean. When you make a sound, sound waves travel through the air. You first hear that sound when the sound waves reach your ears. However, if those sound waves hit an obstacle like a building or the walls of a cave, … Read more

The marvelous tricks a helicopter can do are all attributed to its whirling rotor, the large horizontal propeller that spins on top of its body. The blades of the rotor are like its wings. By changing their angle, a pilot can go in any direction or even hover, or stand still. If the pilot wants … Read more

A balloon floats because it has buoyancy, a lifting power given it by the gas inside it. Some gases are heavier than air and some lighter. It is only when a balloon is filled with a gas lighter than the air outside it that it will rise. Carbon dioxide, which you blow into a balloon … Read more

The seeds, or beans, produced by the cacao tree, which grows near the equator, are the basic ingredient in making chocolate. The beans are produced in the pods of the tree. When these pods are ripe, they are cut open and the beans, about the size of lima beans, are removed and piled on the … Read more

For many years, a rubber-like gum base was the chief ingredient in chewing gum. This gum base was made from chicle, a milky juice that comes from the sapodilla tree of Mexico and Central America. But in the middle 1900s, chewing gum manufacturers created synthetic gum base out of rubber, wax, and plastic. In the … Read more

A submarine has several huge tanks inside it that are filled with air when the ship is floating on the surface of the water. It is this air, which is lighter than water, that keeps the sub afloat, or buoyant, just like any other kind of ship. But these tanks are different from those on … Read more

According to Newton’s law of gravity, every object exerts a pull on the things around it. Since the earth is millions of times bigger than the things around it, it pulls everything toward itself. If this were not so, everything on earth, including people, would go floating off into space. Why then, when a ship … Read more

A pen that carries a supply of ink inside it is called a fountain pen. This ink supply is in a reservoir, either a disposable cartridge or a rubber, sac-like container inside the pen’s barrel. Disposable cartridges can be removed completely and replaced with a new one when they run dry, but the sac is … Read more

Even though pencils are called “lead pencils,” they do not contain lead. The material that makes a pencil write is a mixture of graphite (a kind of ground carbon), clay, wax, and chemicals. To make a pencil, dried, ground graphite, clay, and water are mixed together at high speeds. The mixture is put into a … Read more

Have you often felt what a bother it was to use soap when a quick swish of your hands under plain water would do just as well? Most kids prefer it that way. But while water alone may remove some of the dirt from the surface of your skin, soap added to the water does … Read more

Pick up ashes from a fire after it has cooled down and what do you get? Dirty hands! Touch some grease from left over cooked meat and what do you get? Dirty hands! But take some water and mix it with those same ashes and that same grease. Then rub it on your dirty hands. … Read more

Sugar cane and sugar beets produce most of the sugar we use. Even though these plants grow in different climates, sugar cane in the tropics and sugar beets in temperate zones, once their sugar is refined, there is very little difference between the two. Sugar cane stalks grow from old stalks planted in the ground. … Read more

The tea plant grows mainly in the Far East, with India leading the world in production. These plants are raised from seeds produced by the white flowers on the plants. They are grown on large farms called tea gardens. When the tea plant is from three to five years old and about three to four … Read more

Welding is a method used to permanently join two pieces of metal. Heat is applied to two of the metal surfaces or edges, usually with a gas torch or an electric welding tool. However, when large surfaces are to be welded, large machines are used. The heat applied by the machines melts the two surfaces … Read more

Plate glass for automobile windshields has an ingredient added to ordinary glass to make it into safety glass. The glass is built up in separate layers, much like a sandwich. Between each of two layers of flat glass is a filling of plastic material that binds them together in a process called lamination. Even though … Read more

Before humans learned the secret of glassmaking, nature was the world’s only glassmaker. Lightning striking sand melted it into long, thin tubes of glass, and volcanoes erupting melted rocks and sand into glass. The earliest glass made by humans was probably a glaze on ceramic pottery made somewhere around 3000 B.C. Today, three inexpensive ingredients, … Read more

Ever since the ancient Egyptians first discovered that drying grapes preserved them, improved their flavor, and made them sweeter, people have been enjoying raisins. Most raisins today are made from seedless grapes which grow on vines in large grape orchards. Each grape vine, with the proper care, can produce fruit for 100 years. After the … Read more

The ancient Egyptians used a tall, reed-like water plant from the Nile River as the world’s earliest paper. This plant, called papyrus, has stems from 3 to 10 feet tall. These papyrus stems were cut in long strips and laid side by side. Other strips were placed at right angles on top of them, and … Read more

Vinegar is made by a chemical change called fermentation. During fermentation, the sugar in wine or juice is changed into alcohol and gas. As the gas evaporates, it leaves only the alcohol and fruit flavors. The next step in the fermentation process is called oxidation, when the oxygen in the air mixes with the vinegar … Read more

Bacteria are tiny, one-celled organisms that can be found almost everywhere, in the deepest oceans, in the thickest soil, and up to 90,000 feet in the atmosphere. There are many kinds of bacteria, some which cause deadly diseases and some which are helpful to man. Those which are harmful cause diseases in man, animals, and … Read more

Nylon was the first of the synthetic fibers made by man, and is considered one of the most important chemical discoveries because of its toughness, strength, elasticity, and resistance to oil and grease. In the late 1920s and the early 1930s, chemists at the DuPont Company first produced nylon by combining chemicals they extracted from … Read more

When you are sick, your mother takes your temperature with a glass thermometer containing silvery liquid called mercury. This type of thermometer, the mecury-in-glass type, is made in four parts: a sealed glass tube, a glass bulb at the bottom (the part you put in your mouth), a scale of measurements, and a liquid, such … Read more

The ancient Greeks and Turks have been called the “Fathers of Modern Diving.” As they dove for sponges in the Aegean Sea more than 2,000 years ago, they learned many techniques which are still useful to divers today. These ancient divers realized that the more air a diver took down underwater with him, the longer … Read more

Boomerangs are V-shaped devices, opening at an angle anywhere from 90° to 160°, depending on their use. There are two types of boomerangs, the returning and the non-returning. The best known type is the returning. When thrown correctly, this type returns to the thrower without his moving and so is used mainly for fun or … Read more

Basically, a telescope is a long tube with magnifying lenses at both ends. The end you put to your eye has two convex (curved outward) lenses, which magnify the image. At the far end of the telescope is a concave (curved inward) lens which draws in the light. The distance between these two sets of … Read more