64 THE ELECTRIC TELEGRAPH. 



other end with L, in addition to the other connections, and 

 by adjusting the screw d', so that when at rest the armature, 

 reposing on the poles, does not touch it ; but as soon as the 

 neutralisation occurs, it is lifted up by the force of the spring, 

 and the coils short circuited by contact of D with d'. 



The speed of transmission attained with this apparatus 

 is very great. The chariot and type-wheel revolve about 

 120 times in a minute, and an expert manipulator can trans- 

 mit on the average two letters during a single revolution of 

 the shaft. 



The word " telegraph," for example, is completed in six 

 turns, as follows : 



1st turn blank and t. 



2nd . . * , . e and I. 



3rd ' . , 7 1 . e. 



4th ....'. g and r. 



5th a and p. 



6th . . "V . . h. 



The French word " bonte " is done in four turns : 



1st turn blank. 



2nd .... , b and 0. 



3rd n and t. 



4th . .... . e'. 



Another example is the word " dintz," more fortunate 

 than either, being transmitted during a single revolution. 



This invention was brought by Professor Hughes from 

 America, before the submersion of the old Atlantic cable, 

 on which he made his first important experiments on the 

 speed attainable in working his apparatus on submarine 

 lines. Since then important improvements have been 

 made in the construction and mechanical execution of the 

 apparatus, in the atelier of M. Fromont of Paris. The 

 principles have, however, undergone no change. 



The system has been adopted by the United Kingdom 

 Telegraph Company, under an arrangement giving the 

 Company the exclusive right to use the apparatus them- 



