THE ROYAL ARTILLERY INSTITUTION. 
481 
the old semaphore, by a horizontal bar thrust out to the " proper right.” 
Those who see this bar on the “ proper left ” will know that they are in 
rear of the vane/and must interpret the signal accordingly. 
Tor ordinary field purposes, such as for practice ranges (artillery and 
infantry), and for moderate distances, I am inclined to adopt the dimensions 
recognised as sufficient in the present flashing system—viz., a vane measuring 
4 ft. by 2 ft. Tor permanent works and for communicating with detached 
forts, the size can be increased according to circumstances, still retaining 
the same proportion. Tor field work no mechanism is necessary, but in 
the larger sizes for permanent stations a simple crank and lever, connected 
with an index finger below, can be adjusted so as to work the vane at any 
moderate height above the parapet. 
The vane may be used with any existing code. The foregoing remarks 
presuppose the use of a code, but if spelling be required, a simple method 
of converting figures into letters will at once suggest itself. The above 
provides for 12 numerical signs, while the alphabet for telegraphic purposes 
can be reduced to 24 letters; thus, by the aid of a repeat signal—such 
as the complete rotation of the vane—the ordinary numeral indicated 
can be augmented by 12 and represent a letter. Thus 5 with a repeat 
would signify 5 + 12 = 17, which, according to the key used, may 
indicate any letter or cipher. A spelling system is, however, not so rapid 
as a code. 
The vane may conveniently be made of sheet zinc, sufficiently thick to 
prevent bending, and pivoted at the centre of the figure by means of a ball 
and socket joint, which permits the vane to rotate in one vertical plane. Such 
a vane weighs about 3 lbs., if of the dimensions already stated, but the weight 
is so very inconsiderable that the dimensions might be increased with advan¬ 
tage. If perforated with holes, it would offer less resistance to 'the wind. 
The post or standard may be made of a few feet of iron gas-pipe, into which 
the socket of the vane may fit. They can be made for about five shillings 
each. A more portable vane may be made on a framework similar to the 
frame of an umbrella. The umbrella should open quite flat, and the vane 
be painted in white on the black background of the umbrella, which can be 
closed when not in use. 
A modification of the vane can be made available for night signals, as 
shown in Tig. 3, which consists of a frame of three arms pivoting at the 
Fig. 3. 
