Diurnal Cotidal Lines Small 270×320 Medium 540×640 Large 864×1024 Download Tiff Original 2025×2400 | (308.3 KB) Description This figure shows "the cotidal lines and lines of equal amplitude for a diurnal tide in a circular sea of 20 degrees radius, the latitude of the center being 30 degrees north." -Coast and Geodetic Survey, 1901 Keywords cotidal lines, diurnal tides, round tide diagram, tidal theory Galleries Tides Source: Coast and Geodetic Survey: July 1, 1899, to June 30, 1900 (Washington, DC: United States Government Printing Office, 1901)