94 Mr. H. Wilde's Experimental Researches 



in insulated vessels, for the purpose of comparing the results 

 with those obtained when the same conductors were immersed 

 in liquids in contact with the earth. 



142. A large wooden tub, partially filled with the same canal- 

 water as that in which the previous experiments were made, was 

 insulated from the ground by means of three fireclay bricks 

 (fig. 14) ; and in this tub the two ring-electrodes of naked cop- 

 per rope were immersed with the planes of the rings about 3 

 inches apart. 



143. On making contact between the 5-inch intensity-arma- 

 ture and the coils immersed in the tub, a resistance to the pas- 

 sage of the current (as manifested by the non-heating of thin 

 wire at N) was experienced, similar to that which was observed 

 when the same electrodes were immersed in the canal (113). 

 On diminishing the distance between the electrodes from 3 inches 

 to 1 inch, the 3 inches of thin wire '016 of an inch in diameter 

 was now made red-hot, as was the case when these coils were 

 immersed at the same distance from each other in the canal (126). 



144. Similar effects of resistance to the passage of the current 

 from the 5 -inch intensity-armature to those obtained with the 

 naked ring-electrodes were also experienced when the tape- 

 covered ring-electrodes were immersed separately in the tub at 

 the same distances from each other as in the preceding expe- 

 riment. 



145. Again, no transmission of the current sufficient to heat 

 thin wire at N occurred when contact was made between the 

 coiled electrodes, when 3 inches apart, and the 2^-inch machine, 

 or a single Grove's cell — the results agreeing in this respect also 

 with those obtained in the canal. 



146. The tape-covered conductors were now rearranged in the 

 tub as a double coil of twin conductors, bound together with 

 string, with the ends C, D disconnected. 



147. On transmitting the current from the 10-inch intensity- 

 armature through the immersed coil, 5 feet of wire *065 of an 

 inch in diameter was melted at N, while the current from the 

 5- inch quantity-armature made 15 inches of wire *050 of an 

 inch in diameter bright red-hot, whereas the current from the 

 same armatures melted respectively 6 feet and 15 inches of the 

 same-sized wires when the double coil was immersed in the 

 canal (129) — a result which again shows, but in a converse man- 

 ner, that the mutual influence of the conductors upon one another 

 was supplemented by the inductive influence of the earth, as in 

 the case where the conductors were extended jointly and sepa- 

 rately in the canal (114, 128). 



148. Contact was now made between the double coil and a 

 single Grove's cell ; but although the galvanometer indicated 



