Massey's patent, frictionless ocean depth sounder
1836
"Sub Sig" echo sounder type 301/642 recorder
1954-1963
Piezoelectric Sounder: PVDF bimorph. Uses Kureha film
Original Neale sounder
Neale sounder with tubes
Telegraph sounder
direct reading polarised sounder and example of polarised polechanger
1920-1925
Sporton's improved form of Graham Bell's original sounder
Sir William Thomson's Triple Depth Gauge, one of two, 1880
1880
Sounder using 9 micron piezo film
Ebel sounder with stylograph
Morse sounder, 900 ohms, GPO No. 19161
Post Office sounder
Neale's sounder
Detaching claws and sinker weight for depth sounding, made by Carmelo Bonnici
1857
Hydra weight-detaching sounder for collecting small samples from the sea bottom
1868
Detaching-weight sounder, or ‘Brooke’s Rod’, designed by Ensign Brooke
1855-1860
Skead's detaching-weight sounder used for telegraph survey operations
1857