Accomplishments

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.  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 depend on a fast-evaporating liquid like Freon to rapidly chill whatever it comes in contact with.  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. These waves hit a thin iron disc in the mouthpiece and make it vibrate. This disc is connected to a transmitter, which consists partly of a box filled with carbon grains.  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 as complete pictures. Instead, each picture is taken apart, sent out via electrical waves, and finally put back together in your set. Here's how it works.  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 sends these electrical waves out through the air as radio waves. Radio waves travel through space in all directions, just as waves of water spread out when a pebble is dropped into it.  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 current and change it into vibrations. These vibrations are directed into a stylus, or cutting needle, atop a blank record.  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.  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 conductor of electricity and since it has an amazing ability to give off light which can be seen at great distances, it is used most frequently in airplane beacons, in lamps, and in advertising signs.  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 we wanted them off and insert it to start them up again.

What a switch does is stop and start the movement of electric current, which is continuously flowing into our homes. The most common kind of switch used in homes is called the knife switch, because of its knifelike handle and blade.  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 stored chemicals (a zinc container filled with a copper rod, carbon grains, and manganese dioxide) and a loop of wire hooked to two terminals, or ends. There are always loose electrons, or electric particles, in the wire.  read more »