The solution of this great problem, though long delayed, came swiftly, once it was begun.

Even the simple facts regarding "Masters of Space" and their lives of struggle and accomplishment in sending messages between distant points form an inspiring story of great achievement.

W.K.T.

#MASTERS OF SPACE#

I

COMMUNICATION AMONG THE ANCIENTS

    Signaling the Fall of Troy—Marine Signaling among the
    Argonauts—Couriers of the Greeks, Romans, and
    Aztecs—Sound-signaling—Stentorophonic Tube—The Shouting
    Sentinels—The Clepsydra—Signal Columns—Indian Fire and Smoke
    Signals.

It was very early in the history of the world that man began to feel the urgent need of communicating with man at a distance. When village came into friendly contact with village, when nations began to form and expand, the necessity of sending intelligence rapidly and effectively was clearly realized. And yet many centuries passed without the discovery of an effective system. Those discoveries were to be reserved for the thinkers of our age.

We can understand the difficulties that beset King Agamemnon as he stood at the head of his armies before the walls of Troy. Many were the messages he would want to send to his native kingdom in Greece during the progress of the siege. Those at home would be eager for news of the great enterprise. Many contingencies might arise which would make the need for aid urgent. Certainly Queen Clytemnestra eagerly awaited word of the fall of the city. Yet the slow progress of couriers must be depended upon.

One device the king hit upon which was such as any boy might devise to meet the simplest need. "If I can go skating tonight," says Johnny Jones to his chum, "I'll put a light in my window." Such is the simple device which has been used to bear the simplest message for ages. So King Agamemnon ordered beacon fires laid on the tops of Mount Ida, Mount Athos, Mount Cithæron, and on intervening eminences. Beside them he placed watchers who were always to have their faces toward Troy. When Troy fell a near-by fire was kindled, and beacon after beacon sprang into flame on the route toward Greece. Thus was the message of the fall of Troy quickly borne to the waiting queen by this preconceived arrangement. Yet neither King Agamemnon nor his sagest counselors could devise an effective system for expediting their messages.

Prearranged signals were used to convey news in even earlier times. Fire, smoke, and flags were used by the Egyptians and the Assyrians previous to the Trojan War. The towers along the Chinese Wall were more than watch-towers; they were signal-towers. A flag or a light exhibited from tower to tower would quickly convey a certain message agreed upon in advance. Human thought required a system which could convey more than one idea, and yet skill in conveying news grew slowly.

Perhaps the earliest example of marine signaling of which we know is recorded of the Argonautic Expedition. Theseus devised the use of colored sails to convey messages from ship to ship of the fleet, and caused the death of his father by his failure to handle the signals properly. Theseus sailed into conflict with the enemy with black sails set, a signal of battle and of death. With the battle over and himself the victor, he forgot to lower the black flag and set the red flag of victory. His father, the aged Ægeus, seeing the black flag, believed it reported his son's death, and, flinging himself into the sea, was drowned.

In time it occurred to the great monarchs as their domains extended to establish relays of couriers to bear the messages which must be carried. Such systems were established by the Greeks, the Romans, and the Aztecs. Each courier would run the length of his own route and would then shout or pass the message to the next runner, who would speed it away in turn. Such was the method employed by our own pony-express riders.

An ancient Persian king thought of having the messages shouted from sentinel to sentinel, instead of being carried more slowly by relays of couriers. So he established sentinels at regular intervals within hearing of one another, and messages were shouted from one to the other. Just fancy the number of sentinels required to establish a line between distant cities, and the opportunities for misunderstanding and mistake! The ancient Gauls also employed this method of communication. Cæsar records that the news of the massacre of the Romans at Orleans was sent to Auvergne, a distance of nearly one hundred and fifty miles, by the same evening.

Though signaling by flashes of light occurred to the ancients, we have no knowledge that they devised a way of using the light-flashes for any but the simplest prearranged messages. The mirrors of the Pharaohs were probably used to flash light for signal purposes. We know that the Persians applied them to signaling in time of war. It is reported that flashes from the shields were used to convey news at the battle of Marathon. These seem to be the forerunners of the heliograph. But the heliograph using the dot-and-dash system of the Morse code can be used to transmit any message whatever. The ancients had evolved systems by which any word could be spelled, but they did not seem to be able to apply them practically to their primitive heliographs.

An application of sound-signaling was worked out for Alexander the Great, which was considered one of the scientific wonders of antiquity. This was called a stentorophonic tube, and seems to have been a sort of gigantic megaphone or speaking-trumpet. It is recorded that it sent the voice for a dozen miles. A drawing of this strange instrument is preserved in the Vatican.

Another queer signaling device, built and operated upon a novel principle, was an even greater wonder among the early peoples. This was known as a clepsydra. Fancy a tall glass tube with an opening at the bottom in which a sort of faucet was fixed. At varying heights sentences were inscribed about the tube. The tube, being filled with water, with, a float at the top, all was ready for signaling any of the messages inscribed on the tube to a station within sight and similarly equipped. The other station could be located as far away as a light could be seen. The station desiring to send a message to another exhibited its light. When the receiving station showed its light in answer, the tap was opened at the bottom of the tube in each station. When the float dropped until it was opposite the sentence which it was desired to transmit, the sending station withdrew its light and closed the tap. This was a signal for the receiving station to stop the flow of water from its tube. As the tubes were just alike, and the water had flowed out during the same period at equal speed, the float at the receiving station then rested opposite the message to be conveyed.

Many crude systems of using lights for signaling were employed. Lines of watch-towers were arranged which served as signal-stations. The ruins of the old Roman and Gallic towers may still be found In France. Hannibal erected them in Africa and Spain. Colored tunics and spears were also used for military signals in the daytime. For instance, a red tunic displayed meant prepare for battle; while a red spear conveyed the order to sack and devastate.

An ancient system of camp signals from columns is especially interesting as showing a development away from the prearranged signals of limited application. For these camp signals the alphabet was divided into five or six parts, and a like number of columns erected at each signal-station. Each column represented one group of letters. Suppose that we should agree to get along