Figure 15. K. Grein’s photometer invented and made by Klaus Green in 1912 as part of a series of photometers devised in collaboration with Wolfgang Ewald. This instrument was first tested from the EIDER in 1913 between 500 meters water depth. As a result of these tests, Grein began studies of the penetration of ultra-violet light into the sea.
Photo Category: Oceanography - Historical instruments