Sir Humphry Davy’s Mercury Air Holder, 1800

Davy_Mercury_Air_Holder_1800

Fronticepiece for Humphry Davy’s “Researches, Chemical and Philosophical”, published in 1800.  A mercury-seal gasometer that predates Hutchinson’s spirometer by over 40 years.  The counterweight is attached to a cam that varies the force over the range of motion of the bell.  This device was used as an air holder, not as a measuring device since the only scale for volume was a uncalibrated dial on the cam.  Found on PublicDomainReview.com.

Leave a Reply

Your email address will not be published. Required fields are marked *