8 
THE TELEGRAPH. 
electrically marking the same figures. He carried insulated 
conductors to certain distances; but the difficulty of insulating 
them, the high electrical intensity required, and the depend¬ 
ence of the action on the state of the atmosphere, led him to 
think that his plan of communicating by electricity could 
never be realized. 
It is curious to observe that Claude Chappe entertained for 
a short time the idea of utilizing 
the very agent which was destined 
to afterwards displace his own 
telegraph. 
After many failures, however, 
Claude Chappe succeeded at length 
in perfecting a system of visual 
telegraphy in which signals were 
repeated from station to station, 
by means of an apparatus, the upper 
portion of which was composed of 
three pieces each capable of being 
separately moved (Fig. 1). The 
largest of these pieces, having the 
form of a very elongated paralle¬ 
logram w T ith two other pieces 
mounted at its extremities, can be 
placed in four different positions, 
namely, horizontal, vertically, or 
inclined at 45° right or left. Each 
of the attached moveable pieces, 
called wings, can be made to 
assume seven different positions 
as regards the principal piece, by 
forming v r ith it, above or below an angle of 45°, a right 
angle, or an obtuse angle, and by coinciding with it in 
direction. The three will thus produce 196 different figures, 
w T hich may be regarded as so many simple signals, to each of 
which any determined meaning may be attached. It will 
easily be seen that by placing in any direction a series of such 
machines, each of which repeats the movements of that which 
precedes it, the figures made at the first station, are trans¬ 
mitted to the end of the line, as are the ideas that have been 
Fig. 1. 
