Professor Lodge, in reply, said he could perfectly understand the position of those who held that a lightning rod properly fitted up never failed to do its duty, because, whenever it failed, they said it was not properly fitted up. The great resource in such cases was to ascribe the failure to bad earth contact. He thought a good earth contact was a very good thing, but he could not understand why such extraordinary importance should be attached to it. A lightning rod had two ends--an earth end and a sky end--and he did not see why good contact was more necessary at one end than at the other. If a few sharp points sticking out from the conductor were sufficient for a good sky contact, why were they not sufficient also for a good earth contact? Besides, though a bad earth contact might explain why a certain amount of disruption should take place at the earth where the bad contact existed, he did not see how it accounted for the flash shooting off sideways half-way down the conductor. Again, what does a bad earth contact mean? If an electrical engineer finds a resistance of a hundred ohms, he will rightly pronounce the earth contact to be very bad indeed. But why should the lightning flash leave a conductor with a resistance of a hundred ohms in order to follow a line of non-conductors where it encounters a resistance of many thousand ohms? He accepted the statement of Mr. Preece that his whole theory depended on the existence of oscillations in the lightning discharge; but there was good reason to believe they existed, because they were proved to exist in the discharge of a Leyden jar. Mr. Preece objected that an oscillating discharge could not produce magnetic effects, as a flash of lightning was known to do. He confessed he was unable to explain how an oscillating discharge produced such effects;[43] but that it could produce them there was no doubt whatever, for the discharge of a Leyden jar produces magnetic effects, and we have ocular demonstration that the discharge of a Leyden jar is an oscillating discharge. As to the assurances we had received from electrical engineers that a properly fitted lightning conductor never fails, he should like to ask them how the Hotel de Ville, in Brussels, had been set on fire by lightning on the 1st of last June. The system of lightning conductors on this building had been erected in accordance with the received theory, and had been held up by writers on the subject as the most perfect in Europe. Unless some explanation were forthcoming to account for its failure, we could no longer regard lightning conductors as a perfect security against danger.