Figure 10. Protected Six thermometer constructed by Negretti and Zambra in 1857 . This type of thermometer protected the reservoir of mercury against the effec ts of pressure by having a second glass envelope which inhibited the heating effect of the pressure.

Image ID: ship4290, Voyage To Inner Space - Exploring the Seas With NOAA Collect
Photographer: Y. Berard
Credit: Oceanographic Museum of Monaco

Category: Oceanography/Historical instruments/

• High Resolution Photo Available