150 THE ELECTRIC TELEGRAPH. 



of L B goes from z to E (earth), E' of Station II., c, battery 

 L B' (whose current adds itself to that of L B), c, back contact 

 of T', lever, coils of R', line, coils of R, over the lever T, and 

 back to c of L B. 



The armatures of R and R' are therefore continually 

 attracted to the insulated contacts, and the local circuits are 

 open. When one of the keys is pressed down upon its 

 front contact and the circuit interrupted, the armatures of 

 both the relays are simultaneously released, falling upon their 

 working contacts, closing the local circuits, and putting the 

 Morse machines, M and M', in motion. 



Frischen, who has more than any one else given his 

 attention to the application of closed circuit methods for 

 railway and other lines, had constructed plans of connections 

 for station apparatus, for translation between two lines 

 worked by closed circuit, and also for translation between a 

 line with closed circuit and another worked with intermittent 

 currents. 



Fig. 83 represents a plan of connections for translation 

 with closed circuits. RI and R 2 are the relays of the two 

 apparatus at the intermediate station ; K s T two switches, 

 which, when the arms are in the middle between T and s, 

 establish contact between 1 and K ; when the arm of a switch 

 rests on T, contact is made between it and T, and that between 

 K and 1 interrupted by means of a cam of ivory on the arm, 

 which lifts it up ; and, lastly, when the arm rests on s, 

 contact is established between them, whilst that between K 

 and 1 is also made. M and M' are the two Morses of the 

 usual construction, but with an additional contact at the end 

 of the lever which makes and breaks contact between T of the 

 switch and the line battery. K and K' are the manipulating 

 keys, B the local battery common to both local circuits, and 

 L B the line battery of the station. 



For station work, the handles of the switches on both sides 

 are placed on s ; and the circuits of these and the corre- 

 sponding terminal stations are established through the line, 

 coils of the relay, arms and contact s (of switches), 1 and 2 

 of keys, L B, earth, &c. The tongues of the relays are there- 



