106 THE ELECTRIC TELEGRAPH. 



send the message first to B ; B would receive it and forward 

 it to C ; C, in like manner, to D ; and, lastly, D to E. 



This method was adopted once, and not only took away 

 much valuable time, but was found to be a prolific source of 

 mistakes, which crept into the unfortunate despatches so 

 transmitted. 



The arrangement introduced by Morse, described before, 

 to remedy these inconveniences, remained for some years in 

 abeyance. At length a modification of his plan was adopted. 

 It consisted in making the printing lever of the instrument 

 at station B perform the functions of a transmitting key for 

 the line between B and C, and, by the motions imparted to 

 it by the currents arriving from A, of sending the currents of 

 another battery on to C. At C the instrument does the 

 same, and so on, until the despatch finally reaches E, in the 

 same signals, and practically at the same instant as the 

 despatch left the hand of the operator at A. The manipula- 

 tion at the intermediate stations is therefore performed by 



the apparatus without the least in- 

 terference on the part of the em- 

 ployes. 



Fig. 57 is a plan showing the 

 manner in which the printing-beam 

 of the Morse apparatus is arranged 

 to perform this duty. L 1 , L 2 are 

 the up and down lines, A current 

 arriving by L 1 passes through the 

 coils m m' of the electro-magnet 

 to earth, and back to the trans- 

 mitting station. The beam b of 

 57 ' the recording apparatus is deflected 



from its position of rest on the contact screw 1, and makes 

 contact with the screw 2. A circuit is thus closed : Earth, 

 c (battery), z, 2, b, L 2 , line to the next station on the side of 

 L 2 , recording apparatus, and earth. Through this circuit 

 the current of the battery c z passes as long as the current 

 from L 1 attracts the armature, and keeps the beam b against 

 the contact 2. 



