Extra-terrestrial life.- Huygens (Christiaan) The Celestial worlds discover'd: or, conjectures concerning the inhabitants, plants and productions of the worlds in the planets, second edition in English, 5 folding engraved plates, title neatly strengthened at inner margin recto with archival tape and with a large bookplate removed from verso with residue staining, plates 2 and 3 lower margins trimmed away (just touching image of plate 1), occasional spotting, contemporary panelled calf, spine in compartments and with red morocco label, joints splitting and strengthened with small piece of brown textured tape at head and foot, but holding, corners worn, rubbed and marked, [ESTC T53996], 8vo, Printed for James Knapton, at the Crown in St. Paul's Church-Yard, 1722.

⁂ Second English edition of this work speculating on extra-terrestrial life. Huygens argued that 'the Earth holds no privileged position among the other planets. It would therefore be unreasonable to suppose that life should be restricted to the Earth alone'. Huygens's 'Cosmotheros' first appeared in Latin in The Hague in 1698, with the first English edition following that same year.

Provenance: Professor David Arnold Keys (1890-1977), physicist, Professor at McGill and manager of the Canadian atomic project; gifted to Isabel Williamson, editor of 'Skyward', the newsletter of the Montreal Centre of the Royal Astronomical Society of Canada (bookplate of former and inscriptions to front free endpaper).