Figure 31. Thoulet round dredge, designed by Julien Thoulet, professor at the
University of Nancy, about 1897. Although tested aboard the Princess Alice in
about 1901, it was not until 1909 that Thoulet tested his dredge in small lakes.
That same year they were used in the Gulf of Gascogne on the PRINCESS ALICE II
in depths up to 4600 meters.