Sounding Machine with Lead – Edw. Massey, London, ca. 1810
Mechanical device that consists of a brass plate with a rotating vane that drives a counter by means of a worm screw; on one side the dial reads fathoms up to 160, on the other side tens of fathoms. A circular blocking device automatically stops the vane from rotating when it touches the seabed.Edward Massey’s (c. 1768-1852) mechanical deep-sea sounding machine was patented in 1802. It was not the first mechanical machine that was patented by the Englishman John Christopher Van Berg back in 1636, but Massey’s was the first to become a commercial success. The Board of Longitude awarded Massey £ 200 for his invention and recommended the British Navy to buy five hundred of them.
Massey’s sounding machine was an improvement on the commonly used hand lead. The sounder was clipped on the line just above the lead using the two thumbscrews with lever. The instrument was based on the same design principle as his rotating log for the measurement of the ship’s speed.
This model 5, made by Thomas Walker & Co., has been modified at a later time. For the lead, a Bofor anti-aircraft shell was used, filled with lead and a steel handle. The handle is attached to the instrument with the aforementioned thumbscrews.
Identical sounding machines, but without lead are in the collections of the National Maritime Museum in Greenwich and Het Scheepvaartmuseum in Amsterdam.
Date: ca. 1850
HWL mechanical device: 20x27x8 cm (8×10.5×3.1 in)
L lead with handle: 72 cm (28 in)
Signed: 5 EPM MASSEY’S SOUNDING MACHINE
The rotor is marked with an anchor and the tradesign of T. Walker