One of the great rhythms of our world is the incessant rise and fall of the tides, the interaction of sun, moon, ocean, and earth. Humankind has observed the tides for thousands of years and was able to roughly correlate the relative position of the sun and moon with the state of the tides, but it was not until Sir Isaac Newton formulated the theory of gravitation that the cause of tides became known.
Tidal observations were first made by observing the rise and fall of tides as registered on a graduated staff, but by the mid-Nineteenth Century several types of automatic recording tide gauges were operational. After accumulating masses of data and correlating with astronomic observations of the sun and moon, it became possible to bring tidal predictions within the reach of computation by the latter half of the Nineteenth Century. Tide and tidal current tables became regular additions to the products of the Coast Survey.