I8fl PHILOSOPHICAL TRANSACTIONS. [aNNO 1787. 



gathered up the fragments of Lauder's hat, which had been torn to innumerable 

 small pieces ; as well as part of his hair, which was strongly united to some of the 

 fragments which had composed the crown of the hat. About 44- feet behind 

 each wheel of the cart, was an odd appearance in the ground ; a circular hole of 

 about 20 inches in diameter the centre of which was exactly in the tract of each 

 wheel. The earth was torn up, as if by violent blows of a pick-axe, and the 

 small stones and dust were scattered on each side of the road. The tracks of 

 the wheels were strongly marked in the dust, both behind and before these holes, 

 but were completely obliterated for upwards of a foot and a half on these spots. 

 This led Mr. B. to suspect, that the force which had formed them must likewise 

 have acted strongly on the wheels ; and, on examination, he found evident marks 

 of fusion on each of them. The surface of the iron, to the length of about 3 inches, 

 and the whole breadth of the wheel, had become of a bluish colour, had entirely lost its 

 polish and smoothness, and had the appearance of drops incompletely formed on its 

 surface ; these were of a roundish form, and had a sensible projection. To ascertain 

 whether these marks were occasioned by the explosion which had turned up the 

 ground, he pushed back the cart on the same tracks which it had described on 

 the road ; and found, that the marks of fusion answered exactly to the centre 

 of each of the holes ; and that, at the instant of the explosion, the iron of the 

 wheels had been sunk deep in the dust. They had made almost half a revolu- 

 tion after the explosion, which might be occasioned by the falling down of the 

 horses, which pulled the cart a little forward. On examining the opposite part 

 of the wheels, or that part which was at the greatest distance from the earth 

 no mark of any kind was observable. The broken earth still emitted a smell 

 something like that of ether. The ground was remarkably dry, and of a gra- 

 velly soil. 



It would appear, that this great explosion had, in an instant, pervaded every 

 substance connected with the cart, the wheels of which had probably conducted 

 it from the ground. They had been completely wetted but a few minutes 

 before, as well as the legs and bellies of the horses, and might perhaps be the 

 reason why the hair on these parts was much more burnt than on the rest of 

 their bodies. However, the two horses had already walked over this electrical 

 mine, without having produced any effect ; and had not the cart followed 

 them might have escaped without hurt. He examined all their shoes, but could 

 not perceive the least mark on any of them, nor was the earth broken where 

 they had trodden. But the cart was deeply laden, and the wheels had penetrated 

 much farther into the ground. 



The equilibrium between the earth and the atmosphere seems at this instant 

 ' to have been completely restored ; for no further appearance of thunder or light- 

 ning was observed within the hemisphere ; the clouds dispelled, and the air 



