26 THE SCIENTIFIC PAPERS OF 



We now approach the subject of submerged conductors, which 

 at the present time engrosses the attention of electrical engineers, 

 and also commands a large share of public interest, owing both to 

 the difficulties with which it is surrounded, and the vast import- 

 ance of the object in view. 



Regarding the history of submarine cables, it appears that the 

 first experiments, on a small scale, to submerge an insulated 

 conductor (copper wire coated with cotton thread saturated with 

 pitch and tar) were made at Calcutta, in 1839, by Dr. (now Sir) 

 William O'Shaughnessy. 



Professor Wheatstone proposed in the following year to establish 

 a cable between England and France, and prepared very elaborate 

 and well considered plans, which, by his kindness, I am enabled to 

 place before the meeting. The cable Wheatstone proposed con- 

 tained six separately insulated copper wires which were protected 

 by a strong sheathing of iron, differing, however, from the 

 sheathing now adopted, in being devoid of strength in a longi- 

 tudinal direction. 



Submarine telegraphs must, however, have proved impracticable 

 but for the timely discovery of gutta-percha, and its remarkable 

 insulating properties. It is, therefore, not surprising that the 

 first successful attempts to establish subaqueous conductors were 

 made by Werner Siemens in 1848, in the bay of Kiel, and in 

 crossing the Rhine at Cologne, and other rivers. 



The gutta-percha -coated copper wire was at first submerged 

 without outer protection, but it was laid by the side of a strong 

 chain to protect ib from anchors. In the following year, however, 

 a lead coating was introduced. 



The first attempt to establish a subaqueous conductor across the 

 open sea (from Dover to Calais) was made by Wollastone, in 1850. 

 It consisted of a gutta-percha coated copper wire, without external 

 protection, and failed immediately after it had been laid. In the 

 following year Crampton laid a cable between the same places 

 successfully. This cable was sheathed with iron wire, according 

 to Messrs. Newall and Co.'s patent process, which gives great 

 longitudinal strength, and has been generally adopted evei 

 since, except in the instance of the Varna-Balaclava cable 

 (laid by Messrs. Newall and Co. in 1854), which had no 

 sheathing, excepting at the shore ends, and which worked 



