Tides. New dynamical wave-theory of tides, discovery of physical cause of variation of latitude, with calculation of period and amplitude of polar motion, from observed oscillations of unsyminetrically situated ocean hemisphere, including revised cotidal map of the oceans, now shown to be oscillating in synchronous world-waves coperiodic with disturbing forces, Laplace's principle, with investigation of other laws of motion of the sea hitherto unknown, and improved method for calculating rigidity of the earth; [by T. J. J. See].