Keywords: 099-ferreltpm.jpg of the US Coast and Geodetic Survey Tide-Predicting Machine No 2 2009-09-25 US Department of Commerce Original image PD-US-1923 PD-USGov Scanning Not copyrightable in the country of origin Copyrightable in some European countries though en wikipedia Terry0051 Original upload log of the US Coast and Geodetic Survey Tide-Predicting Machine No 2 This is non-copyright work a it is too old for copyright b a non-copyri</nowiki> Analog computers Tide predictor Maritime navigation Tide predictor Tide gauges Tide-predicting machines |