108 



THE ELECTRIC TELEGRAPH. 



A theoretical plan of the system, arranged for a translating 

 station, with two Morse apparatus, is shown in Fig. 59, in 

 which the letters and other indications of the various pieces 

 on the board correspond, those on the right being dis- 

 tinguished by dashes. G is a galvanoscope, provided with 

 two separate coils of wire of different lengths, the purpose of 

 which is, that the outgoing currents, having their full 

 strength, may pass through the shorter coil ; and the arriving 



Fig. 59. 



currents, which are comparatively weak, through the longer. 

 A single galvanoscope is thus used for showing the strengths 

 of both the currents. The shorter coil, or that intended for 

 showing the transmitted currents, may be short-circuited by 

 means of a contact-peg inserted in a hole between two 

 terminals. 



K is a transmitting key of ordinary construction. 



M is a Morse embossing-apparatus precisely similar to 

 those ordinarily used in Morse circuits. 



