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Tide Predicting Machine No. 2

This machine was designed by Rollin A. Harris and E.G. Fischer and constructed in the instrument shop of the U.S. Coast and Geodetic Survey. It was completed in 1910 and replaced the Ferrel Tide-Predicting Machine in 1912. The machine summed 37 constituents and was capable of tracing a curve graphically depicting the results.

  • Tide-predicting machine no. 2 right side view
    Tide-Predicting Machine No. 2

    Right side view.

  • Tide-predicting machine no. 2 front view
    Tide-Predicting Machine No. 2

    Front view

  • Tide-predicting machine no. 2 setting one tidal constituent's amplitude and phase
    Tide-Predicting Machine No. 2

    Setting one tidal constituent's amplitude and phase.

  • Tide-predicting machine no. 2 recording times and heights of low and high tides
    Tide-Predicting Machine No. 2

    Recording times and heights of low and high tides.


Revised: 10/15/2013
NOAA / National Ocean Service
Web site owner: Center for Operational Oceanographic Products and Services