Figure 10. W. F. Ewald's photometer. Vibration model activated by shaking the
cable that the instrument was attached to. This model was invented by Wolfgang
F. Ewald in 1910 and tested near the coast of Scotland.
Image ID: ship4011, Voyage To Inner Space - Exploring the Seas With NOAA Collect Photographer: P. Roggero Credit: Oceanographic Museum of Monaco