Figure 20. Dumaige thermometer constructed by Paul Dumaige who was a long-time
collaborator with the Prince of Monaco. Duimage was known for having constructe
d the closing mechanism for a plankton net used by Albert I. It is not known
whether this instrument was a copy of an existing instruments or if it was made
to improve certain shortcomings. Two of them were used in 1892 at 4808 meters.