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pl23_ship3427.jpg

Submarine sound signaling apparatus in Knight's Modern Seamanship (Seventh Edition 1917)

Image

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https://www.noaa.gov/media/digital-library-photo/pl23ship3427jpg

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