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![Submarine sound signaling apparatus in Knight's Modern Seamanship (Seventh Edition 1917) ship3427.jpg Submarine sound signaling apparatus in Knight's Modern Seamanship (Seventh Edition 1917)](/sites/default/files/styles/max_1300x1300/https/s3.amazonaws.com/s3-east-testmedia-noaa.woc.noaa.gov/dam/Photos/legacy/pl23_ship3427.jpg?itok=bs58fdmK)
Description
Submarine sound signaling apparatus in Knight's Modern Seamanship (Seventh Edition 1917). This system was first invented in the early 1900's.Long distance sound transmission in the ocean for navigational purposespreceded the use of acoustics for depth measurement.
Collection
Voyage to Inner Space