The Ascent of Extranational Tide Tables
The nineteenth century saw the development of tidal prediction from synthetic, which predicts high and low water for diurnal and semidiurnal tides, to harmonic, which deals with the whole tidal profile. Starting in 1839, France had by 1874 calculated fifteen home ports, and her colonies with a volume based on Tonkin in 1873; America had east and west coast high and low water tables for fifteen Atlantic and four Pacific ports in 1868. In the 1870s the harmonic method was much more successful for the tides of India, then the USA and Australia, and in 1896 the US produced a table for the daily tides of seventy ports, on every continent. The 1921 Admiralty table provided worldwide predictions and concluded the second revolution in tidal science.