338 Mv, 3. N. Heardev on a New Form of Telegraph Cable 



was being transmitted from one end, the other end were at the 

 same time brought into an oppositely electrical state by applying 

 the negative, or, to keep up my simile, the exhausting end of a 

 battery to it, it is quite clear that the current would pass more 

 readily, being now under the double influence of propulsion from 

 behind and exhaustion in front. 



3rdly. Take now the case of two wires carrying reverse 

 currents, actuated by batteries at the home end, or, what would 

 amount to the same thing, having their home ends connected 

 with the opposite poles of a single battery, but with their 

 remote ends working to earth. Suppose, further, the effects to 

 have reached the remote ends. These two ends will exhibit the 

 characteristic conditions of the ends of the battery with which 

 they are respectively connected, and will appear oppositely elec- 

 trified, producing the ordinary galvanometric indications. 



4thly. Let these remote ends be disconnected from earth, and 

 connected with each other. We shall now have fresh conditions 

 set up, for a positively charged insulated wire will be brought 

 into connexion with a negatively charged one also insulated, and, 

 according to known electrical laws, the opposite electrical states 

 of these connected cuds should, by their mutual attraction and 

 inductive influence upon each other, still further overcome the 

 resistance in that portion of the conductor, — the exhausting 

 influence of the negative end accelerating the flov/ from the 

 positive one, and thereby at the same time diminishing the 

 intensity of the current, and its tendency to charge the dielectric. 

 The two cableswould now, indeed, form one continuous conductor, 

 including, if necessary, a telegraphic instrument between them. 



Now if during the passage of a current through a very 

 extensive closed circuit of a resisting character, it shall be at 

 all admitted that the ends nearest the battery will at any time 

 exhibit opposite electrical conditions the i-elative intensities 

 of which shall diminish towards the centre of the circuit, it 

 follows that the telegraphic instrument between the remote ends 

 of the two cables will be situated in the part least likely to be 

 disturbed by inductive action. Not only would this be the 

 case, but it Avould be less liable to disturbance from the residual 

 charge of the dielectric ; for if, after the transmission of a signal, 

 the two home ends be disconnected simultaneously from the 

 battery, and either brought to earth or closed into circuit, the 

 whole of the actions set up to regain the normal condition will 

 be in the direction of the two home ends, leaving the centre, 

 viz. the point of junction of the two remote ends, comparatively 

 free from these disturbing influences. A galvanometer at this 

 point ought therefore to be simply influenced by the actual 

 direction of the current in the wire, and not by the residual 



