Hygrometer from Daniell in good working order ca 1880
Will be securely packaged and sent by registered mail, shipping costs depending on the destination
John Frederic Daniell, a young English natural philosopher, described this type of hygrometer in 1820. It consists of two glass balls, one partially filled with ether and the other covered with muslin, connected by a thin tube from which the air has been evacuated. There is a thermometer in the tube above the ball with the ether, and another on the supporting stand. When a few drops of ether are poured onto the muslin, their evaporation chills the covered ball; that in turn causes the ether vapor inside the instrument to condense, thereby cooling the other ball and causing dew to form on its surface.
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Early Science antiques was founded in 1978 by Fred de Vree based in the Netherlands where I can also be visited by appointment. I have been active for 4 decades as an antiqair and auctioneer, the last 20 years of which are specialized in scientific antiques. I visit collectors and fairs in many European countries. looking for special items please feel free to contact me by Phone or email ,if you need any information on my listed items or something you are looking for 0031653132842 email@example.com