THE ELECTEIC TELEGRAPH. 



Fig. 25. 



Fig. 26. Dover and Calais. 



81. In the Dover and Calais cable, 

 which was the first fabricated and 

 laid, each of the four copper wires 

 are surrounded by gutta-percha, 

 which in fig. 26 is indicated by the 

 light shading round the black central 

 spot, representing the section of the 

 copper wire. The four wires thus 

 prepared were then enveloped in the 

 general mass of prepared spun yarn, 

 represented by the darker shading. 

 The ten galvanised iron wires were 

 then twisted around the whole, so as 

 to form a complete and close armour. 

 The external form and appearance of 

 this heliacal coating is represented in 

 fig. 25. 



This cable which was completed by 

 Messrs. Newall and Co., in three 

 weeks, measured originally 24 miles 

 in length. Owing to the manner in 

 which it was laid down this was 

 found insufficient to extend from 

 coast to coast, although the direct 

 distance is only 21 miles. It was 

 therefore found necessary to manu- 

 facture an additional mile of cable, 

 which being spliced on to the part 

 laid, the whole was completed, and 

 the electric communication between 

 Dover and Calais definitively estab- 

 lished on the 17th October, 1851. 



The cost of the cable itself was 

 9000?., being at the rate of 360?. per 

 mile. The total cost for cable and 

 stations at Dover and Calais was 

 15,000?. 



82. The next submarine cable laid 

 down was that which connected 

 Holyhead on tke Welsh with Howth 

 on the Irish coast. While several 

 companies which had been formed 

 for the purpose, were occupied in 

 raising the capital necessary for this 

 project, they were surprised by the 



154 



