VOL. XLV.] PHILOSOPHICAL TRANSACTIONS. 445 



the observers were smartly struck. This demonstrated, that in these instances 

 the moist ground of the meadows made part of the circuit. The observers were 

 distant from each other about 500 feet. 



The observers then, stationed as in the last experiment, stood on the wax 

 cakes as before, without touching the ground with the iron rods, or any part of 

 their bodies, and the charged phial was exploded 4 times. These were not at 

 all felt by the observer next to b, and without the greatest attention would not 

 have been perceived by him next to a ; and then only in some of the trials, the 

 feeling of the electricity was like that of a small pulse between the finger and 

 thumb of that hand which held the wire. The loaded phial was again discharged 

 4 times more, without any other alteration in the disposition of the apparatus 

 than that the observer next to b stood on the ground ; when the electrical com- 

 motion was perceived by that observer, though not so sharp as when the other 

 observer at the same time stood on the ground. The observer next to a felt the 

 tingling between his finger and thumb as before. 



The gentlemen were desirous of trying the electrical commotion at a still 

 greater distance than any of the former through the water, and where, at the 

 same time by altering the disposition of the apparatus, it might be tried, whe- 

 ther that power would be perceptible through the dry ground only at a consider- 

 able distance. Highbury Barn beyond Islington was thought a convenient place 

 for this purpose, as it was situated on a hill nearly in a line, and almost equi- 

 distant from two stations on the New River, somewhat more than a mile asunder 

 by land, though following the course of that river their distance from each other 

 was 2 miles. The hill between these stations was of a gravelly soil; which, 

 from the late continuance of hot weather without rain, was dry, full of cracks, 

 and consequently was as proper to determine whether the electricity would be 

 conducted by dry ground to any great distance, as could be desired. Accordingly, 

 on Wednesday, Aug. 5, 1747, they met at Highbury Barn. The electrifying 

 machine being placed up one pair of the stairs in the house there, a wire from 

 the coated phial was conducted on dry sticks as before to that station by the side 

 of the New River, which was to the northward of the house. The length of 

 this wire was 3 furlongs and 6 chains, or 2376 feet. Another wire fastened to 

 the iron bar, with which, in making the explosion, the gun-barrel was touched, 

 was conducted in like manner to the station on the New River to the southward 

 of the house. The length of this wire was 4 furlongs 5 chains and 2 poles, or 

 3003 feet. The length of both wires, exclusive of their turnings round the 

 sticks, was 1 mile 1 chain and 2 poles, or 5379 feet. For the more conveniently 

 describing the experiments made here, we will call the station to the northward 

 D, and the other e. 



At this distance the gentlemen proposed to try, first, whether the electrical 



