VOL. LIV,] PHILOSOPHICAL TRANSACTIONS. 141 



melted ; and all this part appears as if it had been exposed to the fire. The 

 lightning seems to have entered here, and to have been conducted thence by an 

 iron spindle 20 feet in length, and 2 inches in diameter ; of which lO feet were 

 surrounded by the copper ball, vane, and cross ; and the lower half was in- 

 closed in a groove cut through the middle of the solid stones which composed 

 the upper part of the spire, and rested on the bottom of that groove, which was 

 sunk 5 inches deep into the lowest of those solid stones : this last-mentioned 

 stone being 3 feet broad and 1 deep. The interval between the sides of the 

 spindle and the groove made to receive it was filled up by melted lead poured in 

 between them. 



The lightning accumulated in the metal, having its passage towards the 

 earth strongly resisted at this place, *has in expanding itself formed a hole, by 

 bursting off from the lower part of the spindle the stones contiguous to it on 

 that side. At each of the angles of the metal, the stone on which it rested is 

 cracked, which probably was occasioned by the lightning issuing with greater 

 freedom from those parts, than from the fiat surface. No part of the spindle is 

 in the least injured by the lightning, notwithstanding the great quantity which, 

 from its effects, appears to have been accumulated in it.* From hence, as low 

 as to the coniiche, it seems to have been conducted along the surface of the 

 spire, which was wetted by the rain that had fallen in the morning, before the 

 lightning : and having been accumulated in the iron bars, in discharging itself 

 from them, it has made the greatest explosion at this place. 



Under this part the freedom of its passage seems to have been hindered by all 

 the dry stonework underneath, which was defended from the rain by the cor- 

 niches : and it appears from some experiments which I formerly inade,-|- that 

 dry freestone, when warmed to a certain degree (which probably does not exceed 

 the heat which the stones of buildings acquire in hot weather) resists the passage 

 of the electric fluid or lightning so strongly, that with plates of that stone, 

 instead of glass, I performed the Ley den experiment. Under the corniche, the 

 lightning descended only by leaping from one iron to another; and at every leap 

 its force seems to have been weakened, and at last to have been quite dissipated. 

 On examining the inside of the steeple, beginning from the top, the first 

 effect of the lightning that appears is a hole in the stone work, beginning im- 

 mediately above an iron bar which served to support the top of the window or 

 opening, and running upwards towards the two cross iron bars : this, when 



* In the year 1750 the stones surrounding this spindle were so nnuch damaged, that there wa« a 

 necessity of taking them down and rebuilding that part of the spire. The cause of this was not 

 known at that time : it is probable tliat it was occasioned in the same manner as the present acci- 

 dent. — Orig. 



f Phil. Trans, abridged, vol. xi. p, 3-34. 



