290 
POPULAR SCIENCE REVIEW. 
to what may be called train- signalling proper/^ But this 
does not represent the full extent of service rendered by 
electricity to the traffic managers of railways in regulating 
their trains. All stations and all signal-boxes^ when required^ 
are furnished with speaking telegraphs for use in emergencies^ 
and for exceptional cases. The time of the departure, for 
instance, of every special train, for which no time-table has 
been issued, is signalled in this way from the departure 
station to every station on the route ; so that every one knows 
when to expect it, and is able to make provision to keep 
the line clear. This is all independent of, and in addition 
to the train- signalling proper from station to station. Express 
and tidal trains are usually signalled in this way from one 
first-class station or junction to the next; and they, as well 
as all other trains that are out of time, are so signalled to 
all stations concerned. Royal specials are always so sig- 
nalled, and the chief officer of the telegraph always accom- 
panies them with the necessary staff, and apparatus for 
establishing telegraph communication instanter from any part 
of the line, should occasion require. The signal-bells also 
that have formed so much the subject of this communi- 
cation can be arranged without any alteration, and without 
any additional expense, merely by connecting them up diffe- 
rently, — to be rung from any part of the line without the use 
of any portable apparatus. 
In thus illustrating the theory of train- signalling, my en- 
deavour has been entirely to avoid supposititious cases, and 
to take for examples cases that have a real existence. The 
illustrations are taken from a railway with which I am of 
necessity perfectly familiar, and where no expense has been 
spared to carry out train- signalling to the highest degree of 
perfection — a railway where the traffic is so larg’e, that 
nothing short of a very carefully-elaborated system would 
give the officers confidence to do what they undertake to do. 
And all that has been said here of one railway is applicable 
in a greater or less degree to all other railways, in proportion 
as they have with more or less skill and discretion availed 
themselves of the services that are to be derived from 
electricity. 
The interior of a large signal-box, such as the one we have 
correctly designated CD, exhibits a very animated scene, in 
which there are but two actors, a man and a boy, both as busy 
as bees, but with no hurry or bustle. The ruling genius 
of the place is the strong, active, intelligent signal-man, 
standing at one end of the apartment, the monarch, for the 
time being, of all he surveys. Immediately before him in one 
long line, extending from side to side, is a goodly array of 
