AMERICAN INSTITUTE. 527 



circuit was through the water; experiment showed that the cir- 

 cuit Avas as perfect through the grassy meadow as through the 

 water. Subsequently it was found that the electricity had not, 

 in this case, been conveyed by the water of the river, which was 

 two miles in length, but by land, where the distance was only one 

 mile, in which case the electric fluid must have passed the New 

 river twice, and gone through gravel pits and a large stubble 

 field. 



On the 28th of July, 1747, they repeated the experiment at the 

 same place, with the following variation of circumstances : The 

 iron wire was, in its whole length, supported by dry sticks, and 

 the observers stood upon original electrics; the effect that they 

 felt the shock much more sensibly than when the conducting 

 wire had lain upon the ground, and the observers stood upon it 

 also. 



That instead of dipping "their rods into the water, they ran them 

 into the ground each side of the river, 150 feet distant from the 

 water; the shock was smart through the 500 feet. 



Their next object was to try whether the electric fluid could 

 be conveyed through dry land, and at the same time to carry it 

 through water to a greater distance than they had done before. 

 They tried this experiment at Highbury Barn, beyond Islington, 

 on the 5th of August, 1747. Their stations were somewhat more 

 than one mile apart by land, and two miles by water. The elec- 

 tric fluid made the circuit of the water when both the wires and 

 observers were supported upon original electrics, and the rods 

 dipped in the waters of the river. Both observers felt the shock 

 when one of them was in a dry gravelly pit, about 300 yards 

 (1,500 feet) nearer the machine than the former station, and 100 

 yards distant from the river; the conclusion was, that dry gravel- 

 ly ground had conducted the electricity as strongly as water. 



The last experiment made by them was to try whether the 

 electric fluid could be carried twice the distance they had done, 

 and through perfectly dry ground, and they also tried to establish 

 the relative velocities of electricity and sound ! They tried the 

 experiment on Shooter's Hill, on the 14th of August, 1 747, at a 

 time when (as it happened) no shower of rain had fallen for five 



