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the conductor may be large enough to convey to the ground, from the top, all the lightning that enters that part; yet one such small conductor cannot be supposed to exhaust those immense bodies so quickly, as to disable them from striking at the same time other buildings, or other parts of the same building.
A wire, or very small rod of metal, does not seem to be a canal sufficiently large to conduct so great a quantity of lightning to the earth; especially when any part of it, or of the metal communicating with it, is enclosed in the stone work; in which case, the application of it would tend to increase its bad effects, by conducting it to parts of the building which it might otherwise not have reached.
Dr. Franklyn, from observing that the filleting of gold leaf on the cover of a book conducted the charge of five large jars, reasons that a wire will be sufficient to conduct the lightning from the highest buildings to the earth.
But it appears from an experiment of his own, that a much larger body of metal, when inclosed between small plates of thick looking-glass, is not sufficient to conduct a fifth part of such a charge, without being melted, and bursting to pieces the plates of glass.
And it is remarkable, that in those parts of the church where the effects of the lightning are most conspicuous, the iron was inclosed in resisting substance simiiar to the glass surrounding the gold leaf in that experiment.
Wires, instead of conducting the lightning, have frequently been melted by the explosion. So that,
Vol. LIV.
