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 seen, as in M. Romas’s kite, to pass from one of these to the other, as the best and nearest conductor. If danger however is apprehended, a piece of chain may be always at hand to hung occasionally upon the upper knob, so as readily to fall in contact with the lower. Otherwise, if while the metallic communication is divided, though when entire it is apprehended it may be touched with safety, a person should touch the rod above the division and at the same time touch or come very near the rod below the division with any part of his body, and at the same instant if a smart stroke of lightning affected the apparatus, he would certainly be destroyed, as happened to professor Richmann at Petersbourg; the lightning going through his body from one part of the apparatus to the other, which it is believed it will not do, while the metallic communication is compleat.

VIII. I have not heard that there has been here of late any particular mode of buildings, adapted to powder magazines, to diminish the shock of the explosion in case of accident: nor do I believe that any attention has been here given, in constructing these buildings, to prevent, by an apparatus of this kind, the effects of lightning.

These, my Lord, are my answers to M. Calandrini's questions. If they are satisfactory to that ingenious gentleman, or have the least tendency to public utility, I shall be gratiﬁed. As know your Lordship's zeal for philosophical discussions, I have taken the liberty of sending you these queries and

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