Rankine appears to have become specially interested in the problems connected with ship design, after he became Professor of Civil Engineering at Glasgow University in 1855. Conjointly with Mr Isaac Watts, late Chief Constructor of the Navy, and formerly a student of the first School of Naval Architecture; Mr F. K. Barnes, now Surveyor of Dockyards, and Chief Constructor of the Navy, and a distinguished student of the second school; and the late Mr J. R. Napier, a member of the famous Clyde shipbuilding firm, Prof. Rankine produced in 1866 “Shipbuilding: Theoretical and Practical.” This valuable treatise was edited, and for the most part written, by Prof. Rankine, and provides a complete system of information on all branches of shipbuilding and marine engineering, although subsequent progress in certain departments of naval science has made a new edition desirable. The work is also distinguished for its enunciation of several theories connected with the resistance and propulsion of vessels by Prof. Rankine, which have become the accepted basis of modern practice. Of these the mechanical theory of the action of propellers, and the stream-line theory of resistance, are the best known. His investigations and writings on the latter subject were most ably supplemented and confirmed by Mr Froude, whose beautifully-contrived model experiments, coupled with his discovery of the law by which such experiments can be made to afford reliable data for the resistance of full-sized vessels, have laid the profession under even a heavier load of indebtedness. This, however, was not the only work of investigation and experiment with which Mr Froude actively and inseparably identified himself. Taking up a subject which many authorities before him had studied and written upon with but little success—that of the phenomena of wave motion and the oscillation of ships in a seaway—he propounded and demonstrated at the Institution of Naval Architects in 1861, after much careful thought and experiment, a theory with respect to it which at that time was entirely new and striking, but which has since been firmly established as the sound one.