THE ELECTRIC TELEGRAPH. 



an application to telegraphic signalling, which, with whole 

 words and even short sentences, completely succeeded. There 

 is no doubt that it would be possible to arrange an uninter- 

 rupted telegraph communication in the same way between 

 two places at a considerable number of miles distance from 

 each other." 



The purpose of setting up this aerial line was not for the 

 study of telegraphy, nor for the perfection of telegraph 

 apparatus ; but to enable these physicists to institute in- 

 quiries into the laws of the intensity of galvanic currents, 

 under different circumstances, on a large scale. At the 

 same time the lines were used for regulating the clocks at 

 the Cabinet de Physique and observatories. 



The telegraph apparatus consisted of three parts : 



1. The apparatus for production of the currents ; 



2. The receiving instrument ; and 



3. The commutator, or instrument for reversing the 

 currents. 



The arrangements used by Gauss and Weber for the 



production of magneto- 

 electric currents at the 

 transmitting station con- 

 sisted of two or three 

 large bar magnets, n s, 

 Fig. 12, each weighing 

 25 Ibs., fixed together ver- 

 tically, with their simi- 

 lar poles in the same direc- 

 tion, on a stool, PP. A 

 wooden bobbin, a a, sup- 

 plied with handles, b b, 

 and wound with more than 

 one thousand turns of in- 

 sulated copper wire,* rested 



Fig. 12. 



on the stool and around the upper ends of the magnet, 

 so that, on lifting up the bobbin by the handles, a current 



* In the apparatus constructed at a later date "by Gauss and Weber, they 

 increased the number of turns to seven thousand. 



