HISTORY AND PROGRESS. 



141 



the lever c H o, and the drum M. As soon, however, as the 

 current ceases, and the boot is pushed sideways, the conductor, 

 let into the middle of the sole, comes into contact with an 

 insulated platinum ring on -the edge of the drum, and com- 

 municates through the spring S 3 with earth. The course of 

 the current is shown in Fig. 79. In repose it would be as 

 follows : L 2 , /, s 1 , G 2 , earth, opposite station instrument, L 2 . 



Fig. 79. 



In this position the relay is in circuit. If, however, the 

 printing lever H^ be attracted (through the agency of an 

 inward current through L X ) the releasing magnet m will 

 at the same instant attract the lever I to the contact 82, and 

 thus break the relay circuit at S L . The course of the current 

 will then be as follows : + K, 3, printing lever, S 2 , /, L 2 , 

 opposite station instrument, earth, + K ; and as soon as the 

 printing lever makes contact at 2, as follows : K, earth, oppo- 

 site station instrument, L 2 , I, s 2 , printing beam, H L , 2, K. 



Lastly, if the conducting sole of the boot be in contact 

 with the platinum ring o^ of the drum, the following will 

 be the manner of discharging the line : L 2 , 1, n, o lt S 3 , earth. 



The Translating Spring. In translating, the introduction of 

 the main and counteracting batteries into the line is effected 

 by means of the printing beam, in order that when in- 



