Masterpieces of Science 



ing the large sum needed to make and lay a new 

 cable which should be so much better than the 

 old ones as to reward its owners with triumph. 

 He found his English friends willing to venture 

 the capital required, and without further delay 

 the manufacture of a new cable was taken in 

 hand. In every detail the recommendations of 

 the Scientific Committee were carried out to the 

 letter, so that the cable of 1865 was incompara- 

 bly superior to that of 1858. First, the central 

 copper wire, which was the nerve along which 

 the lightning was to run, was nearly three times 

 larger than before. The old conductor was a 

 strand consisting of seven fine wires, six laid 

 around one, and weighed but 107 pounds to 

 the mile. The new was composed of the same 

 number of wires, but weighed 300 pounds to the 

 mile, ^t was made of the finest copper obtain- 

 able. 



To secure insulation, this conductor was first 

 embedded in Chatterton's compound, a prepara- 

 tion impervious to water, and then covered with 

 four layers of gutta-percha, which were laid on 

 alternately with four thin layers of Chatterton's 

 compound. The old cable had but three coat- 

 ings of gutta-percha, with nothing between. 

 Its entire insulation weighed but 261 pounds 

 to the mile, while that of the new weighed 400 

 pounds.* The exterior wires, ten in number, 

 were of Bessemer steel, each separately wound 



* Henry M. Field, " History of the Atlantic Telegraph." 

 New York: Scribner, 1866. 



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