104 Mr. II. Wilde's Experimental Researches 



from a pair of zinc and platinum plates excited by dilute sulphuric 

 acid, was transmitted through the submerged conductors, the 

 galvanometer at C, D indicated the same degree of current as 

 when these conductors were extended in the air, thereby show- 

 ing that the current had sustained no appreciable loss in conse- 

 quence of the non-insulation of the conductors. 



183. On transmitting the current from the single Grove's 

 cell through the submerged conductors, f of an inch of the thin 

 wire was melted at the distant point C, D, being nearly the 

 same quantity as was melted by the same cell when the conduc- 

 tors were extended in the air (106). 



184. On transmitting the current from the 2J-inch machine 

 through the submerged conductors, the quantity of thin wire 

 melted at C, D was 3 inches, whereas 4 inches of the same wire 

 was melted when the conductors were extended in the air, — the 

 result indicating, as in the experiment with the single Grove's 

 cell, that an increase in the electric intensity was attended by a 

 diminution of the amount of current which arrived at the distant 

 ends of the conductors. 



185. This diminution of the amount of an intensity-current 

 arriving at the point C, D, reached its maximum when the cur- 

 rent from the 10-inch intensity -armature was transmitted through 

 the submerged conductors, as in this case the current arriving 

 at C, D, though very considerable, was only sufficient to melt 4 

 feet of wire *050 of an inch in diameter instead of 6 feet of wire 

 *065 of an inch in diameter, which the machine would melt 

 when the conductors were in air. In this experiment it will be 

 seen that the quantity of wire melted at C, D is the same as that 

 melted at N by the current from the same armature when the 

 ends C, D were disconnected (114). From other experiments 

 made with the 5-inch quantity- and intensity-armatures, it ap- 

 peared that just as the amount of electrodynamic effect at N was 

 augmented by increasing the intensity of the current when the 

 ends C, D were disconnected, so also was this augmentation of 

 the electrodynamic effect at N attended by a reciprocal diminu- 

 tion of the amount of current arriving at C, D. On the other 

 hand, just as the electrodynamic effects at N were diminished by 

 lowering the tension of the current when the ends C, D were 

 disconnected, so also was this diminution of the electrodynamic 

 effect at N attended by a reciprocal increase of the amount of 

 current arriving at C, 1). 



186. I have already said that when the two copper conduc- 

 tors were extended in the sea with the ends C, D disconnected, 

 the current from the 2^-inch machine was sufficient to melt 4 

 inches of thin wire at N ; whereas the current from a single 

 Grove's cell, connected with the same arrangement of conduc- 



