In a paper read before the Royal Society of Edinburgh, in June 1905, on the Hydrodynamical Theory of Seiches, Professor Chrystal published a number of formulæ from which could be calculated the periods and positions of the nodes of seiches in lakes of various shapes.

The solutions of the most general problems, involving variations of the three dimensions, are there made to rest ultimately upon certain typical cases in which the element of breadth remains constant while the depth is some defined function of the length. In the paper referred to, formulae are given immediately applicable to lakes of uniform breadth, whose longitudinal sections include concave and convex parabolas, quartic curves, and rectilinear shapes.