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trains were signalled on the same wires, no facilities existed for 

 reducing the apparatus employed for the latter purpose, to a simple 

 form. The case is now becoming different, special wires being 

 largely devoted to train signals ; hence the present system. 



The instrument employed is a large electro-magnet, with a move- 

 able armature, carrying a stem and a hammer, which latter strikes 

 on a bell by the direct force of magnetism. It is provided with a 

 contact-maker, a spring, the depression of which causes a current to 

 circulate. The bobbins are 4 in. X 3 in. ; and are filled with ten 

 pounds of covered copper wire, No. 16 or No. 18. The core is of 

 five-eight inch iron. The armature and appendages weigh 2% oz. 

 Bells of this kind have been in action for five years without cleaning 

 or repairing. The battery is zinc-graphite, and a solution of 1 sulph. 

 ac. + 8 or 10 water. The plates, 7 in. X 3 in., are placed in stone 

 pots that contain about a quart, the zinc standing in a gutta-percha 

 slipper, containing mercury. Batteries of this kind will do their 

 work untended for half a year and longer. 



The language consists of blows on the bell ; the number of blows 

 varies according to the train-signal to be given. The distinctions 

 required for ordinary purposes being few, the bell-language is very 

 appropriate, from its addressing the ear, from its simplicity and from 

 the facility with which, the signals are given and taken. One blow 

 is for the starting of an ordinary train ; two, for an express ; three, 

 for the arrival of a train ; five, for stopping all trains ; six, for testing. 

 This is a general code ; other forms of code are used for protecting 

 level crossings and junctions ; but the fundamental signals of the 

 general code are of universal application. This system was intro- 

 duced five years ago on the South Eastern Railway ; and at the 

 present time consists of about 100 bells, to which additions are in 

 progress. 



The bells are connected in pairs, both bells being in a circuit that 

 terminates in the earth in the usual way, at each station. The 

 signal is made by depressing the spring from its earth-contact, upon 

 the zinc end of the battery, the graphite end being in permanent 

 connexion with the earth. The battery being thus introduced between 

 the bell and the earth, a current circulates along the wire and pro- 

 duces one blow upon the bell. The home bell may be excluded or 

 not from the circuit, when a signal is sent. 



