_Methods of employment._--In signaling with the searchlight the usual method of handling the shaft or beam is identical with that employed with the flag. In the first position the beam is shown vertically, while motions to the right, the left, and directly serve to indicate the elements of the alphabet. Chronosemic signals may also be used in searchlight signaling, the shaft of light being directed intermittently on some conspicuous object, such as a cloud, balloon, or high mountain top.
These signals are pyrotechnic compositions which burn with great intensity of light and color. The colors red, white, and green are found best suited for signaling. The signals are prepared in the form of cartridges and are burned from a holder. The colors burned may indicate the elements of any alphabet, or such other special signals as may be desired.
The Very system employs projected red, white, and green stars, which are shot from pistols held in the hand.
_Description._--The Very pistol is a breechloading, single-shot pistol with an 8-inch steel barrel chambered to receive a 12-gauge commercial shotgun shell. Brass shells are used and are packed in boxes colored to indicate the character of stars employed in loading. The color of the star fired may indicate an element of any alphabet or any special signal which may be desired. The stars rise to a height of about 200 feet and remain visible for some time.
The Ardois system is a special system of night signaling designed to utilize combinations of red and white signal lights in forming the elements of any desired alphabet. Four signal lamps capable of displaying either red or white lights are attached at convenient intervals to a vertical cable or staff rigged between the top of a mast and the deck, if on shipboard, or the ground, if on shore. Illumination is furnished by electrical means and any desired combination of lights is automatically obtainable by operating a keyboard.
This system is valuable on vessels or at permanent shore stations, but the great expense of installation precludes its general use. Wiring diagrams and technical instructions relative to this apparatus are in all cases furnished when the same is issued.
[Illustration: FIG. 13.--The Very pistol.]