CHAPTER V.
Flags as a Means of Signalling—Army Signalling—the Morse Alphabet—Navy Signalling—First Attempts at Sea Signals—Old Signal Books in Library of Royal United Service Institution—"England expects that every man will do his duty"—Sinking Signal Codes on defeat—Present System of Signalling in Royal Navy—Pilot Signals—Weather Signalling by Flags—the International Signal Code—First Published in 1857—Seventy-eight Thousand different Signals possible—Why no Vowels used—Lloyd's Signal Stations.
We propose in this, our final chapter, to deal with the use of flags as a means of signalling; a branch of the subject by no means wanting either in interest or in practical value.
The flags used for army signalling are only two in number if we consider their design, though, as each of these is made in two sizes, the actual outfit consists of four flags. The large size is three feet square, and the smaller is two feet square; the larger sizes are clearly more visible, but on the other hand the smaller save weight and consequently labour; and with good manipulation and clear weather their messages can be followed by observers, with ordinary service telescopes, up to a distance of twelve miles or so. The poles are respectively five feet six inches long and three feet six inches, and the flags themselves are either white with a blue horizontal stripe across the centre, or wholly blue. Only one flag is used at a time, the first being used when the background is dark and the second when light, so as to ensure under all circumstances the greatest visibility.
The person sending the signals should hold the flag pointing upwards to the left, and with the pole making an angle of about 25°, with an imaginary vertical line passing down the centre of his body. The signals are based upon the dot and dash system of Morse. The dot or short stroke is made by waving the flag from the normal position to the corresponding point on the right hand, while for the dash or long stroke the flag is waved till the head of the pole nearly touches the ground.
The Morse alphabet is so constructed that the letters of most frequent occurrence are represented by the shortest symbols, and no letter requires more than four of these for its expression, while figures are all represented by five signs.
The letters of the alphabet are thus represented:—
|
A · — A (æ) · — · — B — · · · C — · — · D — · · E · F · · — · G — — · H · · · · I · · |
J · — — — K — · — L · — · · M — — N — · O — — — O (œ) — — — · P · — — · Q — — · — R · — · |
S · · · T — U · · — U (ue) · · — — V · · · — W · — — X — · · — Y — · — — Z — — · · Ch — — — — |
The following code is adopted to represent figures:—