Masters of Space - Morse, Thompson, Bell, Marconi, Carty | Page 4

of messages. Smoke signals are obtained
by building a fire of moist materials. The Indian obtains his
smoke-puffs by placing a blanket or robe over the fire, withdrawing it
for an instant, and then replacing it quickly. In this way puffs of smoke
may be sent aloft as frequently as desired.
A column of smoke-puffs was used as a warning signal, its meaning
being: Look out, the enemy is near. One smoke-puff was a signal for
attention; two puffs indicated that the sender would camp at that place.
Three puffs showed that the sender was in danger, as the enemy was
near.
Fire-arrows shot across the sky at night had a similar meaning. The

head of the arrow was dipped in some highly inflammable substance
and then set on fire at the instant before it was discharged from the bow.
One fire-arrow shot into the sky meant that the enemy were near; two
signaled danger, and three great danger. When the Indian shot many
fire-arrows up in rapid succession he was signaling to his friends that
his enemies were too many for him. Two arrows discharged into the air
at the same time indicated that the party sending them was about to
attack. Three indicated an immediate attack. A fire-arrow discharged
diagonally across the sky indicated the direction in which the sender
would travel. Such were the methods which the Indians used, working
out different meanings for the signals in the various tribes.
Very slight progress was made in message-sending in medieval times,
and it was the middle of the seventeenth century before even signal
systems were attained which were in any sense an improvement. For
many centuries the people of the world existed, devising nothing better
than the primitive methods outlined above.

II
SIGNALS PAST AND PRESENT
Marine and Military Signals--Code Flags--Wig-wag--Semaphore
Telegraphs--Heliographs--Ardois Signals--Submarine Signals.
In naval affairs some kind of an effective signal system is imperative.
Even in the ordinary evolutions of a fleet the commander needs some
better way of communicating with the ship captains than despatching a
messenger in a small boat. The necessity of quick and sure signals in
time of battle is obvious. Yet for many centuries naval signals were of
the crudest.
The first distinct advance over the primitive methods by which the
commander of one Roman galley communicated with another came
with the introduction of cannon as a naval arm. The use of signal-guns
was soon thought of, and war-ships used their guns for signal purposes
as early as the sixteenth century. Not long after came the square-rigged
ship, and it soon occurred to some one that signals could be made by
dropping a sail from the yard-arm a certain number of times.
Up to the middle of the seventeenth century the possibilities of the
naval signal systems were limited indeed. Only a few prearranged
orders and messages could be conveyed. Unlimited communication at a

distance was still impossible, and there were no means of sending a
message to meet an unforeseen emergency. So cumbersome were the
signal systems in use that even though they would convey the
intelligence desired, the speaking-trumpet or a courier was employed
wherever possible.
To the officers of the British navy of the seventeenth century belongs
the credit for the first serious attempt to create a system of
communication which would convey any and all messages. It is not
clear whether Admiral Sir William Penn or James II. established the
code. It was while he was Duke of York and the commander of
Britain's navy, that the James who was later to be king took this part in
the advancement of means of communication. Messages were sent by
varying the position of a single signal flag.
In 1780 Admiral Kempenfeldt thought of adding other signal flags
instead of depending upon the varied positions of a single signal. From
his plan the flag signals now in use by the navies of the world were
developed. The basis of his system was the combining of distinct flags
in pairs.
The work of Admiral Philip Colomb marked another long step forward
in signaling between ships. While a young officer he developed a
night-signal system of flashing lights, still in use to some extent, and
which bears his name. Colomb's most important contribution to the art
of signaling was his realization of the utility of the code which Morse
had developed in connection with the telegraph.
Code flags, which are largely used between ships, have not been
entirely displaced by the wireless. The usual naval code set consists of
a set of alphabet flags and pennants, ten numeral flags, and additional
special flags. This of course provides for spelling out any conceivable
message by simply hoisting letter after letter. So slow a method is
seldom used, however. Various combinations of letters and