Post Lot Text
First edition of parts I and III, second edition of part II of the most important scientific work of 18th-century Amercia, Franklin's researches into the nature of electricity, including proof that lightning is an electrical phenomenon, his experiments with the Leyden jar, the single-fluid theory, the terms of negative and positive charges, an account of the famous kite theory, and his explanation of induced charges. The text was assembled from a series of letters by Franklin to his chief British correspondent, Peter Collinson, and published with an unsigned preface by John Fothergill. These editions by Cage are printed on paper with turned chainlines (4° with vertical chainlines). The first two leaves cut slightly short, otherwise a fine set in a strictly contemporary binding with the original stab-holes from before the parts were bound together still visible.