Figure 42

Figure 42. Hopfgartner and Arzberger sounder, devised by Lieutenant Franz von Hopfgartner of the Austrian Merchant Marine and Moriz Arzberger, a civil enginee r, this apparatus used the same principle as aneroid barometers which utilized the pressure difference between a wall, isolated or not, and the exterior medium . It was tested in 1876 in the Gulf of Trieste in depths up to 17 meters.

Photo Category: Oceanography - Historical instruments