224 



MODERN ELECTRICAL INVENTIONS 





Advances in telegraphy. The mechanical improvements in 

 telegraphy have been so rapid that at present a single operator 

 can easily send or receive forty words a minute. He can tele- 

 graph more quickly than the average person can write; arid 

 with a combination of the latest improvements the speed can 

 be enormously increased. 



In actual practice messages are not ordinarily sent long 

 distances over a direct line, but are automatically transferred 

 to new lines at definite points. For example, a message from 

 New York to Chicago does not travel along an uninterrupted 

 path, but is automatically transferred at some point, such as 

 Lancaster, to a second line which carries it on to Pittsburgh, 

 where it is again transferred to a third line which takes it 

 farther on to its destination. The modern telegraph is much 

 more complex than the early form owing to the numerous de- 

 vices which have been added to increase its efficiency. 



