43 
been found general enough to cover almost everything, although experi- 
ment has generally been necessary to suggest the consequences of the 
theory. 
The practical applications of electricity have played a most important 
part in the development of the subject in the last sixty years. Indeed, 
a great part of the work of these years has had some practical applica- 
tion in view. One of the first of these practical applications was that of 
telegraphy. The telegraph, being one of the earliest of the practical de- 
velopments, naturally had a great effect in stimulating the advance in 
knowledge of electricity, and hence I give a somewhat fuller sketch of the 
early history than space will permit for the later applications. The dis- 
covery of Stephen Gray in 1729, that the electrical influence could be con- 
veyed to a distance by means of an insulated wire, is probably the first 
discovery of direct influence in connection with telegraphy. As a result 
of this discovery and the investigations which followed it, a considerable 
numberof proposals were made as to the use of the electrical force for 
the transmission of intelligence. The first of these of which I have found 
any record was made in 1787 by Charles Morrison, a Scotchman, and 
there followed other proposals for electrostatic telegraphs by Bozolus in 
1767, Le Sage in 1774, Lomond in 1787, by Betancourt in the same year, 
by Reizen in 1794, Cavallo in 1795, and by Ronolds in 1816. 
The discovery of voltaic electricity, and most directly the discovery 
by Nicholson and Carlisle of electrolysis, gave rise to another group of 
proposals for the application of this discovery to the production of a tele- 
graph. Among those may be mentioned that of S6mmering in 1809, of 
Coxe in 1810, and of Sharpe in 1813. In more recent years of course the 
same application appears in thé chemical telegraphs, some of which are 
capable of giving very satisfactory results and great speed. 
The discovery which had the greatest influence on the development 
of telegraphy was that of Oersted, supplemented by the work of Schweig- 
ger and Ampere. Ampere proposed a multiple-wire telegraph with gal- 
yanoscope indicators in 1820, and a modification was constructed by 
Ritchie. A single circuit telegraph of this character was invented in 1828 
by Tribaoillet, but did not come into use. In 1832 Schilling’s five-needle 
telegraph appeared, and he also used a single-needle instrument; but his 
early death stopped further progress. In 1833 Schilling’s telegraph was 
