Curiosities of Science. 



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 correspond- 

 ing motions of the ball, writes down the words they indicate : 

 from which it appears that he has formed an alphabet of mo- 

 tions. As the length of the wire makes no difference in the 

 effect, a correspondence might be carried on at any distance. 

 Whatever the use may be, the invention is beautiful." 



We now reach a new epoch in the scientific period the dis- 

 covery of the Voltaic Pile. In 1794, according to Voiat's Maga- 

 zine, Reizen made use of the electric spark for the telegraph ; 

 and in 1798 Dr. Salva of Madrid constructed a similar tele- 

 graph, which the Prince of Peace subsequently exhibited to the 

 King of Spain with great success. 



In 1809, Soemmering exhibited a telegraphic apparatus 

 worked by galvanism before the Academy of Sciences at Munich, 

 in which the mode of signalling consisted in the development 

 of gas-bubbles from the decomposition of water placed in a 

 series of glass tubes, each of which denoted a letter of the al- 

 phabet. In 1813, Mr. Sharpe, of Doe Hill near Alfreton, de- 

 vised a voltaic-electric telegraph, which he exhibited to the 

 Lords of the Admiralty, who spoke approvingly of it, but de- 

 clined to carry it into effect. In the following year, Soemmer- 

 ing exhibited a voltaic-electric telegraph of his own construction, 

 which, however, was open to the objection of there being as 

 many wires as signs or letters of the alphabet. 



The next invention is of much greater importance. Upon 

 the suggestion of Cavallo, already referred to, Francis Ronalds 

 constructed a perfect electric telegraph, employing frictional 

 electricity notwithstanding Volta's discoveries had been known 

 in England for sixteen years. This telegraph was exhibited at 

 Hammersmith in 1816 :* it consisted of a single insulated wire, 

 the indication being by pith-balls in front of a dial. When the 

 wire was charged, the balls were divergent, but collapsed when 

 the wire was discharged ; at the same time were employed two 

 clocks, with lettered discs for the signals. " If, as Paley asserts 

 (and Coleridge denies), * he alone discovers who proves,' Ro- 

 nalds is entitled to the appellation of the first discoverer of an 

 efficient electric telegraph. " (Saturday Review, No. 147 t) Never- 

 theless the Government of the day refused to avail itself of this 

 admirable contrivance. 



In 1819, Oersted made his great discovery of the deflection, 

 by a current of electricity, of a magnetic needle at right angles 



* In this year Andrew Crosse said : "I prophesy that by means of the electric 

 agency we shall be enabled to communicate our thoughts instantaneously with 

 the uttermost parts of the earth." 



f To which paper the writer is indebted for many of these details. 



