Summary.—I will now try to sum up the results of this interesting discussion, and state briefly the conclusions which, as it seems to me, may be deduced from it. First, I would remind my readers that a lightning rod has two functions to fulfill. Its first function is to promote a gradual, but rapid, discharge of electricity according as it is developed, and thus to prevent such an accumulation as would lead to a flash of lightning. Its second function is to convey the flash of lightning, when it does come, harmless to the earth. Now, the new views advanced by Professor Lodge in no way impugn the efficiency of lightning rods as regards their first function; and it is evident that the greater the number of lightning rods distributed over a given area, the more perfectly will this function be fulfilled. This is a point of great practical importance which seemed to me, in some degree, lost sight of during the progress of the discussion.
Secondly, it was practically admitted by the highest authorities that the experiments and reasoning of Professor Lodge afford good grounds for reconsidering the received theory of lightning conductors as regards their second function—that of carrying the lightning flash harmless to the earth. But there was undoubtedly a general feeling that it would be rash to set aside, all at once, the received theory on the strength of laboratory experiments made under conditions widely different from those which actually exist in a lightning discharge. Experiments are wanted on a larger scale; and, if possible, experiments with lightning rods themselves.
Thirdly, the testimony of electrical engineers who have had large experience with lightning conductors seems almost unanimous that a lightning conductor erected and maintained in accordance with the conditions prescribed by the Lightning Rod Conference gives perfect protection. It was certainly unfortunate that the Hotel de Ville, in Brussels, which was reputed the best protected building in Europe, should have been damaged by lightning just two months before the discussion took place; but no certain conclusion can be drawn from this catastrophe until we know exactly the conditions under which it occurred.
So the matter stands, awaiting further investigation.
FOOTNOTES:
[41] See his Lectures, published in the Electrician, June 22, June 29, July 6, and July 13, 1888.
[42] See paper read at the meeting of the British Association, in Bath, 1888, published in the Electrician, page 607. September 14.
[43] See a very ingenious hypothesis, to account for this phenomenon, suggested by Professor Ewing in the Electrician, p. 712. October 5, 1888.
Transcriber’s Notes
Errors and omissions in punctuation have been corrected.