Figure 10. Bulldog sounder, invented by Marine Engineer Roughton,
assistant engineer Steil, and naturalist George C. Wallich for use in deep water
sounding operations by HMS BULLDOG in the North Sea and North Atlantic Ocean in
1860 while under command of Sir Leopold McClintock RN. This device was also
used on HMS PORCUPINE in water depths up to 3200 meters in 1862.