‎"CAVENDISH, H.(+) W. WATSON (+) BENJAMIN FRANKLIN (+) J. ROBERTSON‎
‎A Report of the Committee Appointed by the Royal Society, to Consider of a Method for Securing the Powder Magazines at Purfleet.‎

‎London, Lockyer Davis, 1773. 4to. Without wrappers. Extracted from ""Philosophical Transactions"", vol. 63, part 1. Including title-page of volume. Title-page reinforced in inner margin, otherwise a fine copy. Pp. (2), 41-48.‎

Reference : 54347

‎First appearance of Franklin's report on affixing electrical conductors to five gunpowder magazines, a safeguard against the blowing up of a magazine by lightning. When the Purlfeet magazines were struck by lightning in 1777, the powder did not explode, and the buildings escaped serious damage (Weld, History of the Royal Society, 97).‎