The first use of deproteinized rubber was between Florida and the light- 

 house on Fowey Rocks off Miami, Florida. In fact, gutta percha was widely 

 used as an insulation compound until the late 1920' s. 



In 1856 the Atlantic Telegraph Company was formed to cross the Atlan- 

 tic with a telegraph cable. The first attempt in 1857 resulted in failure 

 with the cable breaking in 2000 fathoms of water. In 1858 the Atlantic 

 was actually crossed by a telegraph cable but only 723 messages were 

 carried before failure of the cable. 



In 1866 the first successful transatlantic cable was laid in one 

 piece between Newfoundland and Ireland by the steamship GREAT EASTERN. 

 It consisted of a single copper cable insulated with gutta percha pro- 

 tected with wire wrap covered with jute and tar. The return circuit uti- 

 lized the earth. There were no repeaters, but a Lord-Kelvin terminal 

 device was used to sense extremely weak current Dulses. 



The first submarine telegraph cables loaded to increase cable capa- 

 city were laid by the Danish government between Elsinore and Helsinborge, 

 Sweden. In the early 1920' s the Western Electric Company carried out ex- 

 perimental work to increase the traffic capacity of submarine telegraph 

 cables. This led to the development of Permalloy. Permalloy tape was 

 used to wrap cable conductors to load and shield the cable, thereby in- 

 creasing traffic capacity. In 1924 Permalloy-wrapned cables were put to 

 use. By 1928 the Telegraph Construction and Maintenance Company produced 

 another alloy, Mumetal, which was used similarlv to Permalloy with even 

 superior results. Mumetal was also easier to manufacture. The first 

 Mumetal was laid in 1928. 



Submarine telegraph cables antedated the invention of the telephone. 

 Although Robert Hooke invented the string telephone in 1667, A. G. Bell 

 invented and patented the first telephone of practical use as late as 

 1876. Shortly thereafter, the first submarine telephone cable was laid 

 in the English Channel between St. Margaret's Bav, England, and Sangatte, 

 France. The cable had four conductors. 



The year 1921 was marked by the laying of the first submarine tele- 

 phone cable in the ocean other than river or harbor crossings. Three 

 cables were laid between Key West and Havana. These were also the first 

 of the coaxial cables used in the ocean. In 1923 deep water submarine 

 telephone cables were also laid between the California mainland and 

 Santa Catalina Island 



In 1938 the first cable insulated with telcothene was manufactured 

 by the Telegraph Construction and Maintenance Company. Telcothene, 

 Telegraph Construction and Maintenance Company's name for polythene, was 

 discovered in 1933 bv the Imperial Chemical Industries. 



In 1942 the first submarine repeaters were developed by the Research 

 Department of the General Post Office of England as a result of research 

 conducted during the 1930' s to increase the traffic capacity of cables 

 and to span long distances with high frequencies bv submerged amplifiers. 

 The first repeaters were used in 1943 in the Anglesey, Wales-Port Erin 

 paragutta coaxial cable laid the previous year. These were one-way 

 amplifiers. Nineteen hundred fifty saw the first two-way repeaters used 

 and also the first submarine coaxial telephone cable using submerged 

 repeaters . 



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