TELEGRAPH DOES MIRACLE IN DISTANCE COMMUNICATION TELEX AND TELEPHONE ENTHRALL PRINT COMMUNICATION

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Introduction to Mass Communication MCM 101

LESSON 15

TELEGRAPH DOES MIRACLE IN DISTANCE COMMUNICATION

TELEX AND TELEPHONE ENTHRALL PRINT COMMUNICATION

It was undoubtedly a historic day when scientist Samuel Morse on May 14, 1844 successfully established a

link between Baltimore and Washington DC by transmitting the first tele message `What hath God wrought'

on a device invented by him and which we know as telegraph today.

By this date, it was almost 150 years that print media was active but was not finding way to reach to a large

audience in a short time. There were no rails and motorcars. Transport system was as fast as fresh horses

could maintain it. In rains and harsh weathers communication was blocked.

The news of sending message by wire to a reasonable distance in real time was received with great warmth

by the print industry across the world which was assessing a bright future for it was not possible to reach

larger number of people and at a distance not possible to cover before.

How telegraph system came about?

Fires, smoke signals, and drums have been used since antiquity to transmit messages over long

distances. The term telegraph was coined by scientist Claude Chappe to describe such methods, a version of

which was invented by him and his brothers to signal each other while in school. In 1793 Chappe

introduced in France a form of this system for the transmission of messages based on stations with towers

using a code to transmit signals by the position of crossed arms.

The idea of the electric telegraph was born when the first experimenters with electricity noticed that electric

charges could travel through wires over distances. In 1753 in Scotland Charles Morrison described a system

of 26 wires for transmitting the 26 letters of the alphabet. Electrostatic charges traveling through these wires

deflected suspended balls at the receiving station. However, this was never developed as a practical system.

During the early 19th century, several scientists experimented with the transmission of messages through

electric wires. At this time scientists had gained access to a steady, low-voltage source of electricity. Karl

Friedrich Gauss and Wilhelm Weber transmitted signals over wires and detected them with sensitive

galvanometers around 1833. In England Charles Wheatstone developed a telegraph with a five-needle

galvanometer that indicated the transmitted letters. The Wheatstone telegraph actually came into use,

linking Liverpool with Manchester in 1839. In Germany Carl Steinheil developed a telegraph that printed

coded messages on a ribbon.

The electromagnet, a magnet whose field appears when current is on and disappears when it is off, was

discovered in the 1820s. The American painter Samuel Morse first became acquainted with an

electromagnet when it was shown to him by a young chemist he met on a transatlantic ship. Morse realized

that a magnet turning on and off by transmission of a current from a distant source could be used to send

messages. He soon enlisted America's greatest scientist of the time, Joseph Henry, to develop ways to cause

an electromagnet to work at a distance. The electric telegraph became truly functional with the idea of using

a code of dots and dashes to transmit the letters of the alphabet. Despite this technical help, Morse is given

credit for the invention because he put together a practical system and got people to accept it.

Morse patented his telegraph in 1837 and officially inaugurated a link between Baltimore, Maryland, and

Washington, DC, on May 14, 1844, by transmitting the message "What hath God wrought." The message

was transmitted by a telegraph key, a special switch that allows an electric current to be rapidly switched in

and out; it was printed in the dot-dash code on ribbons of paper.

Morse's telegraph quickly spread in the United States, and later it superseded the existing systems of

Wheatstone and Steinheil in Europe. In 1862, 240,000 km (150,000 mi) of telegraph cable covered the

world, of which 77,000 km (48,000 mi) were in the United States and 24,000 km (15,000 mi) in Great

Britain. Europe and the United States became linked by an underwater telegraph cable in 1866.

All rapid long-distance communication within private and public sectors depended on the telegraph

throughout the remainder of the nineteenth century. Applications were many: Railroads used the Morse

Introduction to Mass Communication MCM 101

telegraph to aid in the efficiency and safety of railroad operations, the Associated Press to dispatch news,

industry for the transmission of information about stocks and commodities, and the general public to send

messages. The telegraph's military value was demonstrated during the Civil War (18611865) as a way to

control troop deployment and intelligence. However, the rival technologies of the telephone and radio

would soon replace the telegraph as a primary source of communication.

Days of the Morse Code

Data was transmitted at about four to

six bits per second in the latter half of the

1800s, which was as fast as a human hand could

tap out Morse code. The unit on the right is the

telegraph key. A metal bar on the receiver (left)

simply banged against another bar when the

current passed through, creating a clicking

sound.

The print medium was still enjoying from the

facility of telegraph that another great facility was made available to it as the period of industrial growth got

into top gear in the 19th century. The new invention was telephone a point to point messaging facility by

spoken words. The information conveying system by reporters of the print media and talking to men-in-

power for obtaining information and passing on to millions others the next day seemed as a dream come

true.

Telephone in historic perspective

Throughout history, people have devised methods for communicating over long distances. The

earliest methods involved crude systems such as drum beating or smoke signaling. These systems evolved

into optical telegraphy and by the early 1800s, electric telegraphy. The first simple telephones, which were

comprised of a long string and two cans, were known in the early eighteenth century.

A working electrical voice-transmission system was first demonstrated by Johann Philipp Reis in 1863. His

machine consisted of a vibrating membrane that opened or closed an electric circuit. While Reis only used

his machine to demonstrate the nature of sound, other inventors tried to find more practical applications of

this technology. They were found by Alexander Graham Bell in 1876 when he was awarded a patent for the

first operational telephone. This invention proved to revolutionize the way people communicate throughout

the world.

Bell's interest in telephony was primarily derived from his background in vocal physiology and his speech

instruction to the deaf. His breakthrough experiment occurred on June 2, 1875. He and his assistant,

Thomas Watson, were working on a harmonic telegraph. When a reed stuck on Watson's transmitter an

intermittent current was converted to a continuous current. Bell was able to hear the sound on his receiver

confirming his belief that sound could be transmitted and reconverted through an electric wire by using a

continuous electric current.

The original telephone design that Bell patented was much different than the phone we know today. In a

real sense, it was just a modified version of a telegraph. The primary difference was that it could transmit

true sound. Bell continued to improve upon his design. After two years, he created a magnetic telephone

which was the precursor to modern phones. This design consisted of a transmitter, receiver, and a magnet.

The transmitter and receiver each contained a diaphragm, which is a metal disk. During a phone call, the

vibrations of the caller's voice caused the diaphragm in the transmitter to move. This motion was

transferred along the phone line to the receiver. The receiving diaphragm began vibrating thereby producing

sound and completing the call.

While the magnetic phone was an important breakthrough, it had significant drawbacks. For example,

callers had to shout to overcome noise and voice distortions. Additionally, there was a time lapse in the

transmission which resulted in nearly incoherent conversations. These problems were eventually solved as

Introduction to Mass Communication MCM 101

the telephone underwent numerous design changes. The first phones made available to consumers used a

single microphone. This required the user to speak into it and then put it to the ear to listen. Thomas

Edison introduced a model that had a moveable listening earpiece and stationary speaking tube. When

placing a call, the receiver was lifted and the user was connected directly to an operator who would then

switch wires manually to transmit. In 1878, the first manual telephone exchange was opened. It served 21

customers in New Haven, Connecticut. Use of the telephone spread rapidly and in 1891, the first automatic

number calling mechanism was introduced.

Long-distance service was first made available in 1881. However, the transmission rates were not good and

it was difficult to hear. In 1900, two workers at Bell System designed loading coils that could minimize

distortions. In 1912, the vacuum tube was adapted to the phone as an amplifier. This made it possible to

have a transcontinental phone line, first demonstrated in 1915. In 1956, a submarine cable was laid across

the Atlantic to allow transatlantic telephone communication. The telecommunication industry was

revolutionized in 1962 when orbiting communication satellites were utilized. In 1980, a fiber-optic system

was introduced, again revolutionizing the industry.

Background

Telephones still operate on the same basic principles that Bell introduced over one hundred years

ago. If a person wishes to make a call, they pick up the handset. This causes the phone to be connected to a

routing network. When the numbers are pressed on a touch-tone keypad, signals are sent down the phone

line to the routing station. Here, each digit is recognized as a combination of tone frequencies. The specific

number combination causes a signal to be sent to another phone causing it to ring. When that phone is

picked up, a connection between the two phones is initiated.

The mouthpiece acts as a microphone. Sound waves from the user's voice cause a thin, plastic disk inside

the phone to vibrate. This changes the distance between the plastic disk and another metal disk. The

intensity of an electric field between the two disks is changed as a result and a varying electric current is sent

down the phone line. The receiver on the other phone picks up this current. As it enters the receiver, it

passes through a set of electromagnets. These magnets cause a metal diaphragm to vibrate. This vibration

reproduces the voice that initiated the current. An amplifier in the receiver makes it easier to hear. When

one of the phones is hung up the electric current is broken, causing all of the routing connections to be

released.

The system of transmission presented describes what happens during a local call. It varies slightly for other

types of calls such as long distance or cellular. Long distance calls are not always connected directly through

wires. In some cases, the signal is converted to a satellite dish signal and transmitted via a satellite. For

cellular phones, the signal is sent to a cellular antenna. Here, it is sent via radio waves to the appropriate cell

phone.

With the combination of telegraph and telephone systems, scientists worked to hand over print media

another great facility in the form of telex

Telex

By 1935, message routing was the last great barrier to full automation. Large telegraphy providers

began to develop systems that used telephone-like rotary dialing to connect teletypes. These machines were

called "telex". Telex machines first performed rotary-telephone-style pulse dialing, and then sent baud dots

code. This "type A" telex routing functionally automated message routing.

The first wide-coverage telex network was implemented in Germany during the 1930s. The network was

used to communicate within the government. At the then-blinding rate of 45.5 bits per second, up to 25

telex channels could share a single long-distance telephone channel, making telex the least expensive

method of reliable long-distance communication.

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