Page:Philosophical Transactions - Volume 054.pdf/292

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This is the lowest mark which is left of the effects of the lightning.

In every part that is damaged, the lightning has acted as an elastic fluid, endeavouring to expand itself where it was accumulated in the metal: and the effects are exactly similar to those which would have been produced by gun-powder pent up in the same places, and exploded. Amongst many other stones thrown to a considerable distance by these explosions, one weighing above seventy pounds was removed fifty yards Eastward from the steeple, where it fell through the roof of a house.

It is evident that these effects would have been prevented, if a sufficiently large metallic conductor had been extended from the metal at the top of the spire down to the earth, communicating with the other metallic parts of the building that lay in it's way.

From several observations which I made on this occasion, such a communication seems necessary in buildings of this form. The iron bars, which were fixed in the stonework of the East arches were struck by the lightning, while those in the arches fronting them on the West side of the same story remained untouched by it. So that I do not apprehend, that a conductor communicating with the West arches only, would have preserved the opposite ones from the damage which they have suffered.

When such buildings are exposed to very large clouds replete with lightning, there is no reason to imagine that they will not convey some of their contents to other metallic parts of the building at the same time as to the metal at the top: for though

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