Flashing Signals from ElectricLight Guns
A NOVEL signal gun has been devised by the United States Navy to transmit visual signals between ships in a fleet of war vessels that are running without lights, and yet not betray their presence to the enemy. Signals flashed by it are visible only to the ship at which it has been aimed or one in line with it.
It resembles the crude weapons used in the early days of gunpowder and is operated from the shoulder. It has a barrel in the form of a tube about five inches in diameter, at the base of which an incandescent electric light is located. It is fitted with a stock and there is a trigger which con-
nects with a switch that flashes on and off the current. Current is supplied to the signal gun by means of a cable that enters the stock. On the top of the barrel are sights for aiming the gun. Signals are flashed by the dot and dash system, short flashes indicatingdots and longer ones, dashes.
Visual signaling between ships at night is usually
done by means of lights hung from the masthead, but their operation betrays the presence of the fleet to enemy ships that may be near by. The flashes from the signal gun are only visible to the ship at which the device is aimed or one that maybe in line with it either closer or further away from the ship from which the signals are sent.
Even though no lights may be showing, one ship knows the approximate location of every other ship when they are in fleet formation and the signal gun may be aimed in the direction of any one of them. When the signal gun is used it is not
necessary to “call” a vessel before sending a message. Knowing that the flashes are not visible to any other ship in the fleet, the men on watch on the bridge of the vessel at which the gun is aimed are in readiness to record the message as soon as they perceive the flashes. The very fact that they see them proves that the signal light is directed at them and that their ship is the one for which the message is intended.
The light located within the barrel of the gun is one of great power and its flashes can be seen for a number of miles at sea, even in cloudy weather.