We have here an instructive instance of the failure of an examination to place rightly the most gifted man; that of Sylvester, in 1837, and Clerk Maxwell, in 1854, both of whom were second wranglers, are equally so. Examinations, however, seldom fail in justly rating candidates when originality is not a necessary qualification, but only a sound knowledge and liberal interpretation of the subjects laid down in the syllabus; a good memory and rapidity of writing will do the rest. Thomson committed the fatal mistake in the tripos examination of devoting too much time to a particular question in which he was deeply interested. It was a curious coincidence that the solution which Parkinson sent in to the same question was almost identical with that of his rival for mathematical honors. On being questioned about the matter by the Moderators, Parkinson said that he had read the solution some time before in the _Cambridge Mathematical Journal_; Thomson's explanation was that the solution given in the Journal was his! As he had not memorized the details, he was obliged of course to work the problem out _de novo_. Parkinson in later years wrote a treatise on elementary mechanics that has long since made way for others; Thomson, on the other hand, published in collaboration with Tait a _Treatise on Natural Philosophy_ for advanced students, which became at once the accepted standard. Throughout this treatise, the view is emphasized that physics deals with realities more than with theories, with mutual relations more than with their mathematical expression. Helmholtz thought so highly of this work that he translated it into German, saying in his preface: "William Thomson, one of the most penetrating and ingenious thinkers, deserves the thanks of the scientific world, in that he takes us into the workshop of his thoughts and unravels the guiding threads which have helped him to master and set in order the most resisting and confused material." And again: "Following the example given by Faraday, he avoids as far as possible hypotheses about unknown subjects, and endeavors to express by his mathematical treatment of problems simply the law of observable phenomena." We are not to think of Thomson, the undergraduate, as of one who gave himself up, mind and body, to his favorite studies; he knew how to combine, in some measure, the _dulce_ with the _utile_, for he was fond of music, and so proficient in the art that he was elected President of the Musical Society. He also took a practical interest in aquatic sports, and on the Cam he could ply his sculls with the best of the men. Indeed, he was fond of the water all through life, his _Lalla Rookh_ being well known on the Clyde and in the Solent. Expert in the navigation of his yacht, he liked to be out on the deep, caressed by wind and buffeted by wave, on which occasions he usually studied, pencil in hand, problems connected with navigation and hydrodynamics.