HISTORY AND PROGRESS. 9 



further explanation, be evident from what has gone before, 

 that in charging the system, shown in equilibrium at a, Fig. 2, 

 the two pith balls, having the same kind of electricity, would 

 repel each other and assume a position similar to that shown 

 at b in the same figure. This would continue as long as the 

 charge lasted. The balls would, in course of time, however, 

 approach each other again by their own gravity, the escape 

 of their electricity into the surrounding air diminishing the 

 repelling force. This could, and perhaps was, effected by 

 Lesage suddenly, by discharging his 

 line as soon as he had given a signal ; 

 in other words, by letting the line and 

 pith balls reassume their state of elec- 

 trical equilibrium. 



14. Lomond, in 1787, by the em- 

 ployment of a delicate electroscope, g> 2 ' 



and combinations of signals, given by the divergence of pith 

 balls, succeeded in transmitting intelligence with the aid of a 

 single line wire. 



A short account of this invention is given by Arthur 

 Young,* in the following words : 



" M. Lomond has made a remarkable discovery in electricity. 

 You write two or three words on a paper ; he takes it into a 

 room, and turns a machine enclosed in a cylindrical case, 

 at the top of which is an electrometer, a small fine pith ball ; 

 a wire connects with a similar cylinder and electrometer in 

 a distant apartment ; and his wife, by remarking the cor- 

 responding motions of the ball, writes down the words they 

 indicate, from which it appears that he has formed an 

 alphabet of motions. As the length of the wire makes no 

 difference in the effect, a correspondence might be carried 

 on at any distance, within or without a besieged town, for 

 instance, or for objects much more worthy of attention and 

 a thousand times more harmless." 



15. In 1794, Reusser proposed, in the Magazin de Voigtfi 

 the construction of a telegraph by means of electrical dis- 



* "Travels in France," vol. i. p. 979, 4th edition. 1787. 

 f Magazin de Voigt, vol. ix. p. 183. 



