LETTFR TO GORDON. 169 



The theory of cable -laying expounded on the 

 above occasion I only made public in the year 1874 

 through the medium of a paper entitled "Contributions 

 to the theory of laying and testing submarine telegraph 

 cables" submitted to the Berlin Academy of Sciences. 

 I have preserved among my papers the copy of a letter, 

 in which on my return I explained my theory to the 

 before -mentioned Mr. Gordon, partner in the firm of 

 Newall & Co. I shall insert this letter here, as it 

 forms the first detailed communication on my theory 

 of cable -lay ing. 



Berlin, 26 th September 1857. 

 Dear Gordon, 



Returning yesterday from my journey I found your letter 

 of the 17th. 



First I will give you some particulars from the report made 

 by engineer Viechelmann, who has to-day returned from Bona. 



There is no doubt that wire No. 1 is injured, and that 

 the injury lies in the neighbourhood of the African coast, and 

 consists in the wire being in conducting connection with the 

 water. It is not improbable that the defect exists where the 

 shore-end is joined to the thinner cable. It has not been 

 possible to determine the precise place, as it is uncertain how 

 much resistance the connection has between the conductor and 

 the water. The place can however lie no farther than four 

 German miles (19 English) from the land, but is probably much 

 nearer. 



Through the amount of the charge and by determinations 

 of the resistance in the metallic circuit according to the 

 accompanying sketch (Figure 1) the situation of the fault may 

 be more precisely determined, if you will make the attempt 

 to take up the wire again from Bona. m and n are the two 

 coils of a differential galvanometer, and w a rheostat. By its 

 means resistance is interposed, until the currents through the 



