Masters of Space - Morse, Thompson, Bell, Marconi, Carty | Page 5

figures are
used to indicate set terms or sentences set forth in the code-book. Thus
the flags representing A and E, hoisted together, may be found on
reference to the code-book to mean, "Weigh anchor." Each navy has its
own secret code, which is carefully guarded lest it be discovered by a
possible enemy. Naval code-books are bound with metal covers so that
they may be thrown overboard in case a ship is forced to surrender.
The international code is used by ships of all nations. It is the universal

language of the sea, and by it sailors of different tongues may
communicate through this common medium. Any message may be
conveyed by a very few of the flags in combination.
The wig-wag system, a favorite and familiar method of communication
with every Boy Scout troop, is in use by both army and navy. The
various letters of the alphabet are indicated by the positions in which
the signaler holds his arms. Keeping the arms always forty-five degrees
apart, it is possible to read the signals at a considerable distance. Navy
signalers have become very efficient with this form of communication,
attaining a speed of over fifteen words a minute.
A semaphore is frequently substituted for the wig-wag flags both on
land and on sea. Navy semaphores on big war-ships consist of arms ten
or twelve feet long mounted at the masthead. The semaphore as a
means of communication was extensively used on land commercially
as well as by the army. A regular semaphore telegraph system, working
in relays over considerable distances was in operation in France a
century ago. Other semaphore telegraphs were developed in England.
The introduction of the Morse code and its adaptation to signaling by
sight and sound did much to simplify these means of communication.
The development of signaling after the adoption of the Morse code,
though it occurred subsequent to the introduction of the telegraph, may
properly be spoken of here, since the systems dependent upon sight and
sound grow from origins more primitive than those which depend upon
electricity. Up to the middle of the nineteenth century armies had made
slight progress in perfecting means of communication. The British
army had no regular signal service until after the recommendations of
Colomb proved their worth in naval affairs. The German army, whose
systems of communication have now reached such perfection, did not
establish an army signal service until 1902.
The simplicity of the dot and dash of the Morse code makes it readily
available for almost any form of signaling under all possible conditions.
Two persons within sight of each other, who understand the code, may
establish communication by waving the most conspicuous object at
hand, using a short swing for a dot and a long swing for a dash. Two
different shapes may also be exhibited, one representing a dot and the
other a dash. The dot-and-dash system is also admirably adapted for
night signaling. A search-light beam may be swung across the sky

through short and long arcs, a light may be exhibited and hidden for
short and long periods, and so on. Where the search-light may be
played upon a cloud it may be seen for very considerable distances,
messages having been sent forty miles by this means. Fog-horns,
whistles, etc., may be similarly employed during fogs or amid thick
smoke. A short blast represents a dot, and a long one a dash.
The heliograph, which established communication by means of short
and long light-flashes, is another important means of signaling to which
the Morse code has been applied. This instrument catches the rays of
the sun upon a mirror, and thence casts them to a distant receiving
station. A small key which throws the mirror out of alignment serves to
obscure the flashes for a space at the will of the sender, and so produces
short or long flashes.
The British army has made wide use of the heliograph in India and
Africa. During the British-Boer War It formed the sole means of
communication between besieged garrisons and the relief forces.
Where no mountain ranges intervene and a bright sun is available,
heliographic messages may be read at a distance of one hundred and
fifty miles.
While the British navy used flashing lights for night signals, the United
States and most other navies adopted a system of fixed colored lights.
The system in use in the United States Navy is known as the Ardois
system. In this system the messages are sent by four lights, usually
electric, which are suspended from a mast or yard-arm. The lights are
manipulated by a keyboard situated at a convenient point on the deck.
A red lamp is flashed to indicate a dot in the Morse code, while a white
lamp indicates a dash. The Ardois