The mathematical difficulties of the theory of rotation arise chiefly from the want of geometrical illustrations and sensible images, by which we might fix the results of analysis in our minds.

On a Dynamical Top, for exhibiting the phenomena of the motion of a system of invariable form about a fixed point, with some suggestions as to the Earth’s motion, read before the Royal Society of Edinburgh (20 April 1857); published in Transactions of the Royal Society of Edinburgh, Vol. XXI, Part IV (1857).