102 Professor J. A. Fleming [March 27, 



the phantom has double the section of copper conapared with the 

 component physical circuits. This alone tends to reduce the attenu- 

 ation constant. It is, therefore, often possiV)le to speak farther 

 throuirh the phantom circuit than through the component or side 

 circuits. 



These cross-Channel loaded cables have very greatly facilitated 

 telephonic communication between England and the Continent. A ■ 

 telephonic service is now given by the General Post Office between 

 London and Geneva, and other cities in the Continent, which is 

 conducted through one or other of the two loaded Channel Cables. 

 ! f Telephonic conversation has also been conducted experimentally 

 between Berlin and London through the loaded Anglo-Belgian 

 €able. 



Another loaded submarine cable between England and Holland, 

 is I believe, in course of construction, which will establish direct 

 telephonic communication l)etween London and Amsterdam, and at 

 the same time, render possible inter-telephonic communication 

 between England and Northern Germany. 



The latest sulanarine telephone cable is the coil-loaded cable laid 

 last year (1913) across the hish Channel under the direction of 

 Mr. W. Slingo, the present Engineer-in-Chief of the General Post 

 Office. This cable, 64 nautical miles long, is a two-circuit cable 

 arranged for phantom working, and is the longest loaded submarine 

 cable actually working. 



At intervals of one nautical mile Pupin coils are inserted, as in 

 the Anglo-Belgian Cable. The attenuation constant at 800 frequency 

 is 0-015. 



The details of all these cables are oriven in Table IL 



f 



