ELECTRICITY DURING THE NINETEENTH CENTURY. B35 



electric arc and found that but few substances escaped fusion or vola- 

 tilization when placed in the heated stream between the carbon 

 electrodes. Here again he was pioneer in every important and quite 

 recent electric work, employing the electric furnace, which has already 

 given rise to several new and valuable industries. 



The conduction of electricity along wires naturally led to efforts to 

 employ it in signaling. As early as 1774 attempts were made by Le 

 Sage of Geneva to apply frictional electricity to telegraphy. His 

 work was followed before the close of the century by other similar 

 proposals. Volta's discovery soon gave a renewed impetus to these 

 efforts. It was easy enough to stop and start a current in a line of 

 wire connecting two points, but something more than that was requi- 

 site. A good receiver, or means for recognizing the presence or 

 absence of current in the wire or circuit, did not exist. The art had 

 to wait for the discovery of the effects of electric currents upon mag- 

 nets and the production of magnetism b}^ such currents. Curiously, 

 even in 1802, the fact that a wire conveying a current would deflect a 

 compass needle was observed by Romagnosi, of Trente, but it was 

 afterwards forgotten, and not until 1819 was any real advance made. 



It was then that Oersted, of Copenhagen, showed that a magnet 

 tends to set itself at right angles to the wire conveying a current, and 

 that the direction of turning depends on the direction of the current. 

 The study of the magnetic effects of electric currents by Arago and 

 Ampere, and the production of the electro-magnet b}' Sturgeon, to- 

 gether with the ver}' valuable work of Henry and others, made possi- 

 ble the completion of the electric telegraph. This was done b}^ Morse 

 and Vail in America, and almost simultaneous!}' by workers abroad; 

 but before Morse had entered the field Prof. Joseph Henry had exem- 

 plified by experiments the working of electric signaling by electro- 

 magnets over a short line. It was Henry, in fact, who first made a 

 practically useful electro-magnet of soft iron. The history of the 

 electric telegraph teaches us that to no single individual is the inven- 

 tion due. The Morse system had been demonstrated in 1887, but not 

 until 1844 was the first telegraph line built. It connected Baltimore 

 and Washington, and the funds for defraying its cost were obtained 

 from Congress only after a severe struggle. This can be easily under- 

 stood, for electricity had not up to that time ever been shown to have 

 any practical usefulness. The success of the Morse telegraph was 

 soon followed by the establishment of telegraph lines as a means of 

 communication between all the large cities and populous districts. 

 Scarcely ten years elapsed before the possibility of a trans- Atlantic 

 telegraph was mooted. The cable laid in 1858 was a failure. A few 

 words passed and then the cable broke down completely. This was 

 found to be due to defects in construction. A renewed effort to lay a 

 cable was made in 1866, but disappointment again followed; the cable 



