EAILWAT COMMUNICATION. 
475 
extent practically successful — plan is Mr. W. H. Preece, tlie 
telegraph superintendent of the South-Western Pailway 
Company^ and the details of the mechanical arrangements are 
as follows : — 
Every compartment is provided with a signal handle or bell- 
pull_, consisting of a drop-ring inclosed in a circular case about 
four inches in diameter, the front of which is fitted with a 
glass, so that at first sight it might be mistaken for a time- 
piece or aneroid barometer, having a white dial or face on 
which directions for the use of the signal are painted. The 
signal handle is defended by glass, thus necessitating the 
breaking of the latter before it can be used, with the object 
of exercising a check on its trivial employment ; and at the 
same time the glass is so thin as to offer little resistance to 
fracture should it become necessary to obtain access to the 
ring. The dial and ring occupy a central position in the com- 
partment, above the heads of the passengers, and just below 
the umbrella-rack. A pull on the ring, acting through two 
diverging wires guided by pulleys concealed beneath the parti- 
tion, disengages two catches, one on either side of the carriage, 
each of which releases in its turn an arm or lever, which in 
falling’ assumes a position at right angles to the sides of the 
carriage, from which it projects on either side like wings, 
and being coloured red and white, in alternate squares, is v 
sufficiently conspicuous to indicate at once the compartment 
from which the signal proceeded. The descent of these levers 
completes the connection between the poles of an electric 
battery in the guard^s van, and instantly sets one or more 
bells ringing, which can only be stopped by replacing the arms 
or levers in their original position. Under the existing ar- 
rangement, the guard has the power of communicating five 
signals to the driver, by whom they are to be acknowledged 
on the whistle. But as at present there are no connecting 
foot-boards or other means of communication by which the 
guard can reach the compartment from which the signed 
emanated, and learn what is the matter to enlighten himself 
as to what signals it may be necessary or advisable to transmit to 
the driver; this end of the scheme must at present be considered 
an abortion, or at least incomplete. The mode of carrying the 
connecting- wires from carriage to carriage, so as to combine 
sure electric connection with facility of detachment, is very 
simple and ingenious, and leaves nothing to be desired-. The 
coupling and uncoupling can be effected instantaneously ; at 
the same time should a carriage become detached from a train 
by accident, the alarm-bell is at once put in action. 
Such is the plan of Mr. W. H. Preece, and after four 
months^ use none of the threatened practical objections seem 
