Telegraphy is the first and most important system of long distance
communication. It has been utilized for ages and is still used today. There are different
kinds of telegraphs—pre-electric and electric telegraphy.
Telegraphy(derives
from the Greek tele, "far", graphein, "to write") is a branch
of telecommunications that consists in the sequential transmission of messages or
dispatches by signs (alphabetic letters, numerals, punctuation, or symbols) or sounds. The
telegraph is a department of telegraphy; it is a system of electric telegraphy. It is a
communication system that requires electrical instruments to transfer, or transmit, and
receive signals, or coded messages, through electrical pulses.
Pre-electric Telegraphy
This type of telegraphy refers to the long distance communication system used during the
ancient days, when electricity did not exist. It can divide itself into three
subcategories: non-literal, literal and visual telegraphy.
Non-literal Telegraphy
Non-literal telegraphy is a pattern that involves transmitting non-alphabetic messages at
an extensive distance. As we remember back in the pre-historic era, man was unfamiliarized
with words and was incapable of speaking. The only known means of communication that could
be produced were sounds or gestures. Just as we, in the present age, use gestures or body
signals to tell others what we want or express to others our feelings, back then, man also
employed them. Another method of producing sounds was by beating objects. Pre-historic man
learned to beat on resounding tree trunks or any piece of wood with a stick, like a drum,
creating rhythmic sequential sounds.
Other non-literal communication systems that were used in ancient times were smoke and
fire signals. Ancient people of Egypt, China, Greece, and Assyria practiced fire
signalling by night and smoke signaling by day to establish sight of locations.
Literal Telegraphy
This type of pre-electric telegraphy requires alphabetic signaling. By 300 BC, a method of
signaling the 24 letter Greek alphabet was invented. This technique consisted of placing
alphabet letters in five rows and five columns on an iron frame in a way that the first
letter of the alphabet, alpha, lies on the first row on the first column; and in a
way that the last letter of the alphabet, omega, lies on the last row of the fourth
column. All that was required was ten vases and two low walls in a row separated from one
another by a few feet. The wall on the left represented the row; the wall on the right,
the column. For example, to signal alpha, one vase was placed in front of the left wall,
while another vase, in the front of the right. To signal omega, five vases were placed in
front of the right wall; four vases were placed in front of the right one. Medieval
prisoners practiced this same system of communication.
Visual Telegraphy
Another system of telegraphy was created…optical telegraphy. A Frenchman, Claude
Chappe, and an Englishman, George Murray, invented optical instruments and semaphores.
These apparatus consisted in the transmission of messages from "hilltop to
hilltop" with the help of a telescope. Chappe invented a system that used a
"vertical beam holding a movable crossbar with indicators at each end that could
assume various configurations". The second instrument, Murray’s apparatus, was
composed of "a large tower-mounted box with six panels that opened and closed in
different combinations according to a code".
