HENRY AND THE TELEGRAPH. 271 



many years, and attracted considerable attention ; and had no simpler 

 device been discovered it might possibly have won its way into use. It 

 is remarkable that some seven or eight years later a Philadeli^hiauinde- 

 l)endently proposed the same scheme. 



1816. Dr, John Redman Coxe, of Philadelphia, professor of chemistry 

 in the University of Pennsylvania, suggested the employment of wires 

 for communicating intelligence by a galvanic current, arranged either to 

 decompose water in tubes, (Soemmering's plan, of which he seems to have 

 been unaware,) or to decompose metallic salts.* As an untried sugges- 

 tion, this has been noticed only because the latter project was afterward 

 successfully developed and executed by others. 



1828. Victor Triboaillet de Saint Amand proposed to establish a gal- 

 vanic telegraph line of a single wire from Paris to Brussels, the con- 

 ducting wire to be varnished with shellac, wound with silk, coated with 

 resin, inclosed in sections of glass tube carefully luted with a resin, the 

 whole substantially wrapped and water-proofed, and finally to be buried 

 some feet deep in the earth. The signaling device is somewhat obscure, 

 as while a strong battery is the source of the current, the receiving in- 

 strument is an electrometer. t This project, also belonging to the purely 

 si)eculative class, scarcely deserves a notice. 



1813. Mr. Robert Smith, of Blackford, Scotland, devised an experi- 

 mental galvano-chemical telegraph carrying out practically the sug- 

 gestion offered by Dr. Coxe in 1810. A set of iron type at the receiving 

 station, each connected by separate wires with a corresponding circuit- 

 key at the transmitting station, was so arranged with reference to a 

 clock-moved band of paper wet with a solution of ferro-cyanide of potas- 

 sium, that when the current was passed through any special circuit, it 

 impressed a blue letter on the band. "A paper containing an account 

 of this t degraph was read before the Royal Scottish Society of Arts on 

 the 27th of March, 1813; reported on by a committee, and approved 

 the 12th of June following. Since that time many trials have been 

 made, and various improvements in its construction have also been 

 introduced by the inventor." | 



Two or three years later Mr. Smith reduced his line to a single circuit 

 of two wires ; and the registering device at the receiving station con- 

 sisted of a fillet or ribbon of i)lain calico wound on a roller j)laced in a 

 trough tilled with a solution of ferro-cyanide of potassium containing a 

 few drops of nitric acid, and unrolled by the motion of clock-work over 

 a leaden c^dinder with which one of the iron wires of the line was in 

 connection, while the end of the other iron wire rested on the wetted 



^Thomson's JwHo/s of PhUosophi), Feb. 1816, vol. vii. p. 162. 



\ Report of Academy of Indnstrii, Paris. Quoted from A. Vail's Electro-Maf/neUc Tele- 

 graj)h, 1845, p. V.io. Also TurnbuH's Elceiro-Magnctie Telegraph, 2d ed. 1853, p. 56. 



\ Practical Afcchanic and En(jineer''s Magazine, Glasgow, Nov. 1845, vol. i, 2d series, 

 l^. 33. 



