90 Mr. II. Wilde's Experimental Researches 



equal length (113): — Although, when the electrodes were three 

 feet apart, a sufficient amount of current was always passing into 

 the canal to produce a spark and shock on breaking contact at 

 N, yet it was insufficient, as we have seen, to heat sensibly wire 

 so thin as '016 of an inch in diameter. When, however, the 

 electrodes were made to approach so as to be within one inch of 

 touching each other, a length of three inches of the above-men- 

 tioned wire was made red-hot. 



127. In order that this mutual influence which the electrodes 

 exercised on each other, to promote an increase of discharge 

 from the electromotors, might be more closely investigated when 

 the distance between the electrodes was still further reduced, 

 the tape- covered twin conductors were submerged in the canal 

 in their extended form, as shown in fig. 11, with the ends AB 

 connected with the respective ends of the aerial conductors, and 

 the distant ends C, D entirely disconnected. From the porous 

 nature of the tape-covering with which the conductors were en- 

 veloped, it will be obvious that this covering, though a good in- 

 sulator in air, would, when saturated with water, oiler little or 

 no obstruction to the passage of an electric current either into 

 the earth or between the conductors. 



128. When the current from the 5 -inch intensity-armature 

 was transmitted through the submerged twin conductors, 2 feet 

 of the same-sized wire which was made red-hot at N when the 

 naked conductors were extended in the canal (114) was now 

 melted. And the current from the 5-inch quantity-armature, 

 which previously only made 15 inches of wire *021 of an inch 

 in diameter warm to the touch, now melted this same wire, and 

 also made red-hot 15 inches of thicker wire, *050 of an inch in 

 diameter. 



129. On coiling the twin conductors into a double ring about 

 2 feet in diameter and immersing it in the canal in the place 

 previously occupied by the separate ring-electrodes of naked 

 copper rope, the 15 inches of thicker wire ('050 of an inch in 

 diameter), which was only made red-hot by the 5-inch quantity- 

 armature in the last experiment, was now melted, thereby indi- 

 cating the passage of a more powerful current from the electro- 

 motor when the twin conductors were coiled into a ring than 

 when they were extended along the bed of the canal. With 

 this arrangement of the double coil, the current from the 

 10-inch intensity-armature melted 6 feet of wire *065 of an inch 

 in diameter. 



130. That the increased quantity of current passing through 

 the twin conductors, above that transmitted through the naked 

 conductors, whether in their coiled or extended form, was due 

 to the direct influence which the twin conductors exercised on 



