. Bulletin. Science. .^ig££i«23aaseEs?^ Earth Figure 40.—Thomson's "speaking galvanometer" and trans- mitting key as used in marine cable telegraphy. From W. H. Preece and J. Sivewright, Telegraphy, New York, 1876, p. 138. machine, George M. Phelps '" of Troy, New York, combined certain features of the House and the Hughes machines to produce the Phelps "combina- tion telegraph" (fig. 39) that could initially send about 30 words per minute and that was constantly improved until it could send up to 60 words per minute. This combination machine, patented in 1859, had con
. Bulletin. Science. .^ig££i«23aaseEs?^ Earth Figure 40.—Thomson's "speaking galvanometer" and trans- mitting key as used in marine cable telegraphy. From W. H. Preece and J. Sivewright, Telegraphy, New York, 1876, p. 138. machine, George M. Phelps '" of Troy, New York, combined certain features of the House and the Hughes machines to produce the Phelps "combina- tion telegraph" (fig. 39) that could initially send about 30 words per minute and that was constantly improved until it could send up to 60 words per minute. This combination machine, patented in 1859, had considerable success where traffic was suf- ficiently heavy to warrant the use of a rather compli- cated and expensive machine. In addition to expanding the telegraph across con- tinents, engineers and investors sought to join tele- graph networks that ended at a coastline. In the 1840's numerous attempts were made to lay a cable under water, but this goal was not attained until gutta-percha was applied as underwater insulation.^' C. V. Walker laid a successful gutta-percha cable along two miles of the English Channel in January 30 George Phelps, patent 26003 (November 1, 1859); George B. Prescott, History, Theory, and Practice of the Electric Telegraph, Boston, 1860, pp. 144-155; Electricity and the Electric Telegraph, New York, 1888, 2 vols., vol. 2, pp. 642-647. 31 C. Willoughby Smith, The Rise and Exteruion of Submarine Telegraphy, London, 1891; Charles Bright, Submarine Telegraphs: Their History, Construction and Working, London, 1898; G. R. M. Garatt, One Hundred I'ears of Submarine Cables, London, 1950. 1849, and later the same year a similar cable was successfully laid under the Connecticut River, at Middletown. The brothers Jacob and John Brett laid a gutta-percha cable between Dover and Calais in 1850, but it remained in operation less than a day. Then the brothers manufactured another cable and placed armor over the gutta-percha. This cable was laid in 1851 an
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