CHAPTER VII. 
VARIOUS APPLICATIONS OF TELEGRAPHY. 
Uses of tlie Telegraph on Railways—Afc Fires—With Armies in the Field— 
For Meteorological Purposes, and for Weather Prediction—For Fishing— 
In the Service of Justice—Floating Stations. 
The telegraph, coming into use at the same time as railways, 
has contributed much to the success of these, for it is difficult 
to imagine how the iron roads could have been worked with¬ 
out the telegraph. 
The apparatus for sending orders along the line is like that 
used for ordinary purposes. For a long time Breguet’s appara¬ 
tus was used at the railway stations in France. But some time 
ago the companies introduced Morse’s apparatus, and the 
clerks daily devoted a portion of their time to practising the 
new method, which has now superseded the dial apparatus. 
We have not, however, now to speak of these telegraphs. 
The public safety requires something more than these com¬ 
munications, namely, the semaphore signals visible to all, 
which indicate to the engine drivers the condition of the line. 
On double lines of railway, where the trains on each line go 
always in the same direction, they can come into collision only 
in consequence of the stoppage or slackening of speed of a 
train that precedes another. The guard then displays a red 
flag at the rear of the train, or in case of a stoppage he 
walks back and places the flag at a certain distance behind. 
When this signal would not be distinctly visible he places 
fog-signcds on the rails, and these explode with a loud report 
when a wheel passes over them. 
Guards, pointsmen, &c., are also instructed to stop, by these 
signals, a train following too closely upon another, so that the 
interval between may be great enough to remove the risk of 
accidents. 
