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