INTERFERENCE ON SUBMARINE TELEGR.ll'II C.IBLES 417 



this ceible and its sea earth taken at the same time and under tlie same 

 conditions as Fig. 1, which is the record of terminal interference on an 

 adjacent non-loaded cable provided with the ordinary type of sea 

 earth. In both cases a large condenser was inserted between the cable 

 and the amplifier to reduce the "zero wander" due to components of 

 very low frequency. Comparison of the two records indicates that the 

 interference on the cable with the ordinary sea earth is about ten times 

 that on the cable with the balanced sea earth. The contrast between 

 the two types of sea earth is still more pronounced at times when 

 terminal interference is unusually large. It has been found possible, 

 for example, to operate the New York-Azores cable during violent 

 local electrical storms when neighboring cables were compelled to 

 cease operation. 



