Museo Galileo
Virtual Museum
Hair hygrometer
    • Setting:
      Room XV
    • Maker:
      Nairne & Blunt firm
    • Place:
    • Date:
      late 18th cent.
    • Materials:
      brass, glass
    • Dimensions:
      height 444 mm, dial diameter 85 mm
    • Inventory:
    • Hair hygrometer (Inv. 2442)

Hygrometer consisting of a glass tube that connects a brass dial to a small plate. The plate carries a mobile clamp whose position can be adjusted with a screw. The hygroscopic fiber (not original) is held by the clamp and winds on a pulley that pivots in a box fixed to the back of the dial. A spring, also connected to the pulley, keeps the fiber taut. A pointer indicates the changes in humidity on the dial scale. Made by Nairne & Blunt.