220 APPLIED SCIENCE 



267. The Story of the Telegraph. Samuel F. B. Morse, 

 an American inventor, holds the most important place in the 

 development of the telegraph. Although Wheatstone and 

 Cooke in England occupied a distinct place in this field, the 

 telegraph system invented by Morse in 1837 is the one that 

 is almost universally used, except for railroad work, to which 

 the needle instruments of the Englishmen are peculiarly 

 adapted. 



Morse was assisted in the practical and mechanical devel- 

 opment of the telegraph by Alfred Vail, an uncle of Theodore 

 N. Vail of more recent telephone and telegraph fame. It 

 was, moreover, through the financial assistance of Alfred 

 Vail's father that Morse was able to put up the first experi- 

 mental line. The telegraph today, in connection with the 

 cable which was perfected some time later, reaches practi- 

 cally every civilized portion of the world, gives employment 

 to thousands of men and women, and renders service to 

 millions of others. 



268. Parts of Telegraph. The telegraph is an instrument 

 used to send messages to a distance by means of electricity. 

 It is usually worked by electrical current or by an electro- 

 magnet. The instrument is made up of four separate parts : 



(1) the generator, or battery to generate the electricity; 



(2) the conductor, or insulated wires by which the electric 

 current is carried to any distance; (3) the transmitter, or 

 instrument which regu'ates the flow of electricity; and (4) 

 the register, which records the signals. The generator is 

 made up of one or more voltaic batteries, each of which is 

 composed of a number of cells connected in a series. The 

 Grove cell was formerly much used and then the Daniell 

 cell; but a cell called the gravity cell, which is as good as 



