There has been much controversy as to whether it is better to carry the conductor from the roof to the ground inside a building than outside the walls. As a matter of fact, it is a question of very small importance which way the conductor is carried, so long as it arrives at the ground by the shortest possible route. Benjamin Franklin, to judge from many expressions in his works, seems to have been decidedly in favour of the inside plan, which was adopted almost universally in France and on the Continent in general on the first introduction of lightning conductors. But the method was soon abandoned, owing partly to a witty saying of Voltaire, constantly quoted to this day. Speaking of the death of the unfortunate Professor Richman, of St. Petersburg, killed while experimenting with electric discharges from the clouds, Voltaire remarked, ‘There are some great lords whom one should only approach with extreme precaution: lightning is such a one.’ A mere jocular exclamation, it would have had no great force except in France, where a _bon mot_ may cause the fall of a king and the dethronement of a dynasty. In regard to Voltaire’s pleasantry about not approaching too close to lightning, it really had in great part the effect of preventing conductors to be laid inside the houses. Even such calm philosophers and men of science as Professor Arago quote Voltaire with approval. ‘I feel inclined,’ he remarks in his ‘Meteorological Essays,’ ‘to admit that the illustrious author (Voltaire) may be right, when I remember a case that occurred in the United States.’ The case relied upon, a very curious one, was as follows, in Arago’s own words.