Symbols

SYMBOLS,SIGNS,SIGNALS & ALPHABET

Early people sought the means by which to record language. They drew and painted on cave walls to convey messages; they used signs and symbols to designate tribe or ownership. As human knowledge expanded, writing became necessary in order to transmit information. Cave Drawings The earliest writing was pictographic, with symbols representing objects. The first pictographic writing was cuneiform, by which wedge-shaped characters were inscribed with a stylus on a clay tablet. Cuneiform later developed ideographic elements; the symbol came to represent not only the object but also ideas and qualities associated with it. Writing, however, continued to convey only the meaning, not the sound, of words. Eventually, cuneiform incorporated phonetic elements, that is, signs that represented certain sounds. Egyptian hieroglyphs underwent a similar development. This system progressed from pictograms to ideograms; it incorporated signs for consonants, but it never developed into an alphabet. The alphabet, invented in the Middle East, was carried by the Phoenicians to Greece, where vowel sounds were added to it. The Cyrillic alphabet was adapted from the Greek; the Latin alphabet developed in countries farther to the west where the Roman culture was dominant.

SIGN SIGNALS GESTURES

Signals- messages that are communicated without written or spoken words- are of two kinds. There are sight signals- something you see, such as the police officer's hand waving you to cross the street. Or there are sound signals- something you hear, like the ringing of a schoolbell. A signal may carry just one message. The doorbell ringing means that someone is at the door. Or signals may be combined into a complicated code, so that taken together, they relate a message that can be translated into words.

DRUMS GUNS BELLS Sound Sign

Thousands of years before the telegraph was invented, people knew that sound traveled faster than even the speediest runner or horse. People sent messages by beating out codes on drums or hollow logs. Each beat had a particular meaning. Far away on a hilltop, the next drummer would hear the message, answer it, and pass it on ;a long distance from its origin.

In pioneer days, American on the frontier sometimes used guns for signals communication. In a small town several revolver shots meant a fire alarm. People sent coded messages by horn blast, gunshots, or ringing bells.

For centuries, people have used bells to ring out an important news. Bells communicate by a sound signal, and everyone within hearing should understand the signal. Bells were used to ring the curfew hour( time to be indoors, off the streets) or to announce that the town crier in the city square had something important to tell. Bells still ring in the new year and call people to church bell sand doorbells signal that someone wants attention. The long, slow. Sad tolling of the church bell tells of a death or a funeral.

The sound of a bell or a siren tells that a fire is near or that an ambulance is coming. In cities, cars stop when they hear the fire siren. During Wartime, sirens signal air raids. Everyone takes shelter when the siren blows.

All these sound signals deliver short but very important messages. Even with all our modern electronic marvels of communication, a bell, or a siren is still one of the quickest, surest ways of getting vital warning to everyone within hearing.

Sight Sign

SMOKE AND LIGHT SIGNALS

Sound signals are fast because sound travels at about 1,220 kilometers (760 miles) an hour. A loud sound communicates its meaning to everyone who hears it, whether or not the person is expecting the message. Signals that you see rather than hear are even faster because they travel by light waves. Light moves at about 300,000 kilometers (186,000 miles) a second. But the receiver has to be watching in the right direction.

Sight signals are sent by means of smoke, fire, or light beams. The American Indians sent messages by smoke signals. The sender waved a blanket over a fire, making the smoke puffs go up in a certain way to form a message. An Indian watching far away could read the puffs and understand the message.

The ancient Chinese ,Egyptien ,Greeks, the Persians all signaled by smoke or fire. Aeschylus , the Greek poet ,records that the news of the fall of troy was sent to Greece by means of a series of bonfires. The Greek historian Herodotus tells us that as early as the 5th century B.C the Greeks signed by reflecting sunlight in a polished metal mirror. This is called heliograph signaling.

Light signals, like bells, are still useful for simple warnings. The lighthouse tells ship captains to stay away from hidden rocky reefs. The brake lights of an automobile tell another motorist to slow down. Traffic lights signal stop and go. But although light travels quickly, its signals. Have a serious disadvantages. The message can travel only as far as a person can see.

Reference

Thinkquest Participation 99Edition(http://www.thinkquest.org)
Entry from Royal College Port Louis Students
Mauritius