THE ARMY AND NAVY ALPHABET.
SIGNALING WITH FLAG OR TORCH, HAND LANTERN, BEAM OF SEARCHLIGHT, AND HELIOGRAPH.
There is one position and three motions. The position is with the flag or other appliance held vertically, the signalman facing directly toward the station with which it is desired to communicate, his body erect and feet sufficiently separated to insure stable equilibrium. The first motion ("one" or "1") is to the right of the sender, and will embrace an arc of 90°, starting with the vertical and returning to it, and will be made in a plane at right angles to the line connecting the two stations. The second motion ("two" or "2") is a similar motion to the left of the sender. The third motion ("front," "three," or "3") is downward directly in front of the sender and instantly returned upward to the first position.
The beam of searchlight will be ordinarily used exactly as the flag, the first position being a vertical one.
To use the torch or hand lantern, a footlight must be used as a point of reference to the motion. The lantern is more conveniently swung out upward to the right of the footlight for "1," to the left for "2," and raised vertically for "3."
In using the heliograph, the first position is to turn a steady flash on the receiving station. The signals are made by short and long flashes. Use short flashes for "1," two short flashes in quick succession for "2," and a long, steady flash for "3." The elements for a letter should be slightly longer than in sound signals.
Each word, abbreviation, or conventional signal is followed by "3."
The full address of a message is considered as one sentence and will be followed by the signal "33."
The signal to indicate that "cipher follows" and "cipher ends" is with the flag and torch "XC3," and with other methods, except the International Code, by "XC." It will always precede and follow a cipher message or such part of a plain text message as is enciphered.
The following conventional signals are authorized in the use of the army and navy alphabet: