‎"LAMBERT, JOHANN HEINRICH‎
‎Essai D'Hygrométrie ou sur la Mesure de L'Humidité. (And:) Suite de L'Essai D'Hygrométrie. 2 vols. - [INVENTION OF THE HYGROMETER]‎

‎(Berlin, Haude et Spener, 1771 and Berlin, C.F. Voss, 1774) 4to. No wrappers, as issued in ""Memoires de l'Academie Royale des Sciences et Belles Lettres"", tome XXV, pp. 68-127 with 3 folded plate, and ""Nouveau Mémoires Année 1772"", pp. 65-102 and 2 engraved plates.‎

Reference : 39089

‎First edition of Lambert's importent work which laid the foundation of the science of Hygrometry and coined the word ""Hygrometer"". The first instrument was build by the instrumentmaker G.F. Brander after Lambert's description. It consisted of a cat-gut string, the expansion and construction of which was transferred to a wheel-work, and shown on a scale divided by 360 gr.. This was afterward adopted by Saussure. - The second paper ""Suite de..."" is devoted to a discussion of the different hygrometers.The principles and construction were later published in his famous book ""Hygrometrie"" Augsburg 1774-75. - Poggendorff I:1356 - Rosenthal, Litteratur der Technologie P. 263. - Attached is two other memoires (Gledisch: Correction caracteristique succinte du Genre de L'Albuca et de L'Alethris de Linné. pp. 57-67 and Beguelin: Extrait des Observations Météorologiques faites a Berlin par Orde de Academie dans les Années 1768. et 1769. pp. 128-164.‎