Digital Library Search
![Figure 11 ship4012.jpg Figure 11](/sites/default/files/styles/max_1300x1300/https/s3.amazonaws.com/s3-east-testmedia-noaa.woc.noaa.gov/dam/Photos/legacy/pl23_ship4012.jpg?itok=go8rWTkY)
Description
Figure 11. W. F. Ewald's photometer, messenger model, at the end of operation.Invented by Wolfgang F. Ewald about 1910 to fix some of the problems of theprevious model. First tested about 1910 off the coast of Scotland. Other tests were then made off Capri. (Image credit: Oceanographic Museum of Monaco | P. Roggero)