pl23_theb3768.jpg
Description
Sounding machine devised by Robert Hooke.Drop glass ball with weight over side.Ball disengages when weight hits bottom.Known rate of descent and ascent - can then derive depth.Never worked right.
Credit
NOAA Central Library
Collection
Historic Coast & Geodetic Survey
Nautical Charting
Bathymetry - Mapping the Features
Pre-1920
Keywords
Charting
Soundings
Bathymetry
Mechanical