A Bohnecke is a mechanical recording current meter, first designed and used in the 1930s, in which the propellor and the compass both drive a set of horizontal dials with raised numbers on their vertical rims.
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A clockwork mechanism moves a strip of tin foil past the vertical rims of the dials and a hammer presses the the foil against the raised numbers on the rims every five or ten minutes. The speed and direction can be obtained from the information on the foil. Wide use of this mechanism was forestalled by the difficulty in finding a material for the spring in the clockwork that could withstand the corrosive exposure to seawater.