Figure 34. Thermometer used with Pettersson-Nansen insulation bottle. This
bottle was a version of the Pettersson bottle with improvements made by Fridtjof
Nansen in 1900. This thermometer was fixed to the inside cover of the bottle
while a reversing thermometer was mounted on the outside. It was first tested
on board the MICHAEL SARS in the Norwegian Sea in 3000 meters in 1900.