VOL. XLV.] PHILOSOPHICAL TRANSACTIONS. 443 



phial to the warm spirit, it was instantly fired, and the electrical commotion felt 

 by the observers on both sides of the rivt;r. 



It was then thought proper to try the effects of the charged phial on the 

 warm spirit, when the wire was divided which was laid over the bridge; on pre- 

 senting the iron hook to the spirit, a sufficient snap was given to the spoon to 

 fire the spirit, but nothing so smart as in the former experiment where the large 

 circuit was completed. 



It was then tried what the effect would be on the spirit, if the charged phial 

 was divested of its long wire which lay over the bridge, and was only held in the 

 hand of an observer; while the spoon with warm spirit was placed in contact of 

 the iron rod beforementioned, to which the wire was connected, which went to 

 the observers on the Surry shore; and the spirit was fired with much the same 

 degree of smartness as in the last experiment. 



In these and all the subsequent operations, wires were made use of to conduct 

 the electricity preferable to chains, as by great numbers of experiments it had 

 been fully proved, that whatever difference there was in the bulk of the con- 

 ductor, viz. whether it were a small wire, or a thick iron bar, the electrical 

 strokes communicated were equally strong; and it had been further observed, 

 besides the difficulty of procuring chains of a requisite length for the present pur- 

 poses, that the stroke at the gun-barrel, when the electricity was conducted by 

 a chain, was caeteris paribus not so strong, as when that power was conducted by 

 a wire. This was occasioned by the junctures of the links of the chain not be- 

 ing sufficiently close, which caused the electricity in its passage to snap and flash 

 at the junctures, where there was the least separation; and these smaller 

 snappings in the whole length of the chain lessened the great one of the gun- 

 barrel. 



Encouraged by the success of these trials, the gentlemen were desirous of 

 continuing their inquiries, and of knowing whether the electrical commotions 

 were perceptible at a still greater distance. The New River near Stoke New- 

 ington was thought most convenient for that purpose; as at the bottom of that 

 town, the windings of the river are such, that from a place which he calls a to 

 another b, the distance by land is about 800 feet, but the course of the river is 

 near 2000. From a to another place c, in a right line is 2800 feet, but the 

 course of the water is near 8000 feet. 



Accordingly, on Friday July 24, 1747, there met at Stoke Newington the 

 president of the Royal Society and several other gentlemen : when every thing 

 being disposed as before, and the wire extended fi-oni a to b and c, over the 

 meadows, without touching the water. When every thing was thus disposed, 

 and the signals given, the charged phial was exploded several times, and the elec- 

 trical commotion every time smartly felt by the observers both at a and B. In 



3 L 2 



