Page:Philosophical Transactions - Volume 054.pdf/281

 gallery to those, which bring the water thence; care being taken that, from the bottom of these last, there should be a metallic communication, if there should be found to be none at present, with the water in the common sewer. Thus, without much expence, a compleat metallic communication maybe made between the top of St. Paul’s church, and the water; which had it been done at St. Bride's, the ravages so lately experienced had in all probability been prevented.

From cosidering the circumstances of this thunder storm, I cannot but be of opinion, that the injury done to St. Bride's prevented mifchief to St. Paul’s. St. Bride’s is a very high building, and within a fmall distance nearly West of St. Paul's. When this distance is considered, and that the lightning came in the direction of St. Bride's to St. Paul's, and that when the thunder cloud came near the former, it exploded there, and parted with much of its force; what was left did no damage to the latter, tho' the much higher and more exposed building, and having a metallic cross at its top.

I have recommended as metallic conductors copper wires of the size of a goose quill; as, when of that thickness, they may easily be bent to any direction; and, where thought necessary, any number may be employed. I look upon this as a kind of standard, from what Dr. Franklin wrote to Mons. Dalibard of Paris upon this subject. He observes, in a church which suffered greatly by lightning at Newbury in New-England, that though a small wire was beaten to pieces by lightning, and dissipated by its force, the rod of a pendulum conducted the whole without Rh