[6], 496 [i.e.508], [16] pp. Advertisement & errata leaf inserted following preface. Illustrated with 7 copper-engraved plates, 2 of which are folding. (4to) 23x16 cm. (9x6½"), modern calf in antique style. Fourth Edition in English, and first collected edition.

First complete edition of "the most important scientific book of eighteenth-century America" (PMM) - and the fourth overall - together with the first printings of other texts. Earlier editions of Franklin's editions of Franklin's electricity were published in separate parts. "The most dramatic result of Franklin's researches was the proof that lightning is really an electrical phenomenon. Others had made such a suggestion before him--even Newton himself--but it was he who provided the experimental proof. In 1752 he flew a kite in a thunderstorm and attached a key to its string. From this he collected electric charges in a Leiden jar and showed that atmospheric and frictional or machine-made electricity are the same...His reputation as a scientist was immediately established by the publication of the results of his researches in a series of letters addressed to Peter Collinson, a London merchant and naturalist..." (PMM). The first edition was published between 1751 and 1754. PMM 199 (1st Ed); Sabin 25506; Waller 11340; Wellcome III, p.62. Formerly in the Nottingham Public Library, with small rubberstamps to title-page, plates, and a few other places.