Figure 12. E. B. Helland-Hansen's photometer. Left: device before opening.Middle: Device during exposure. Right: Device after closing. Invented by Bjorn Helland-Hansen in 1910, this photometer was used aboard the MICHAEL SARSin the North Atlantic
4/4/2019 1:50:12 PM
Photographer: P. Roggero
Credit: Oceanographic Museum of Monaco
Subject: Oceanography
Subject: Historical instruments