Alphabet, Telegraphic.
The combinations of sounds, of dots and dashes marked on paper, of
right-hand and left-hand deflections of a needle, of bells of different
notes, or of other symbols by which a fixed combination is expressed for
each character of the alphabet, for numerals, and for punctuation. While
the code is designed for telegraphic uses it can be used not only for
the conveyance of signals and messages by the electrical telegraphs, but
also by any semaphoric or visual system, as by flashes of light,
movements of a flag or even of the arms of the person signalling.
In the English and continental needle telegraphy in which the message is
transmitted by the movements of an index normally vertical, but
oscillating to one side or the other under the influence of the current,
the latter being controlled by the transmitter of the message, the left
hand swings of the needle are interpreted as dots, the right hand as
dashes.
This system enables one alphabet to be translated into the other, or
virtually one alphabet answers for both Morse and needle transmitters.
There are two principal telegraphic alphabets, the American Morse and
the International codes. They are very similar, their essential
distinction being that spaces are used in the American code, while they
are excluded from the International code.
In the American Morse system the message is now universally received by
sound. (See Sounder--Sound Reading.)