The Late Professor Rankine.

Since the publication of our last number death has removed from among us one of the most eminent authorities on those subjects for the discussion of which this Magazine has been established. In the late Professor Rankine the world has lost a genius of no common order — one, indeed, who for originality of thought, power of reasoning, grasp of mind, and versatility of knowledge, has rarely been surpassed; and one to whom no question of pratical interest was too trivial, no theoretical investigation too abstruse.

Born at Edinburgh, in 1820, of a family of some note in Ayrshire, he early displayed those talents which were later to render him famous. When only sixteen years of age, and while still at college, he gained a gold medal by an essay on the undulatory theory of light, and two years later received an extra prize for another essay on methods of physical investigation. On quitting the University of Edinburgh he chose for himself the profession of a civil engineer, becoming a pupil of Sir John M'Neill, and, though not employed on any works of great note, appears to have gained a large and varied experience. He afterwards actively pursued this profession, both on his own account and in conjunction with the late Mr. John Thomson; but, in spite of his often heavy professional work, he never neglected those scientific investigations he had so early undertaken, and in 1854 received from the Royal Society of Edinburg, of which he had been elected a fellow in 1849, the Keith medal for his researches in thermo-dynamics. The next year he was appointed by the Crown, on the resignation of Mr. Lewis Gordon, Regius Professor of Civil Engineering and Mechanics in the University of Glasgow, an office which he held till his death. During the next seventeen years Professor Rankine rendered this hitherto obscure chair famous throughout the world, and made the humble Scottish University to which it was attached the envied rival, so far as scientific instruction was concerned, of far more pretentious schools of learning. During this short space of time his researches embraced nearly the whole range of mechanical science, and there is scarcely a subject which touched on which he will not long be cited as an authority. Settled permanently at Glasgow — the metropolis, as he himself was pleased proudly to term it, of shipbuilding and engineering — it is not strange that his studies should soon have been directed more closely to these branches of this profession than had hitherto been the case. It may merely have been accidental that Mr. James Robert Napier, bound by a heavy penalty to build a certain vessel to steam at a certain speed, should have applied to Professor Rankine for assistance; but, accidental or not, it is this circumstance which appears to have directed his attention to the theory of naval architecture, and once shown the track, he seems to have pursued it with avidity. Taking as his starting-point the data to be derived from a knowledge of the resistance offered to water in flowing through iron pipes at high velocities, and adapting these to an approximate calculation of the engine-power required by a ship of any given design, Professor Rankine eventually arrived as his theory of stream-lines — a theory which, with its rigid mathematical demonstration, is, with all its imperfections, far in advance of the elegant guesswork that enters into Mr. Scott Russell's wave-line system of construction. Afterwards. instigated by the experiments and investigations of Mr. Froude, he took up the not less difficult question of the rolling of ships among waves, and his treatment of it was scarcely less successful than that of the problem of resistance.

It was in the year 1861 that Mr. Froude laid before the Institution of Naval Architecture his theory of the rolling of ships, the most important advance that had been made in naval architecture for nearly three-quarters of a century. "This question," to employ the words of Mr. Scott Russell, "was one which had hitherto absolutely evaded the investigation of mathematicians and the devices of the naval architect," and it is consequently not surprising that many eminent scientific men should have found a difficulty in accepting Mr. Froude's views when they were first laid before the public. Professor Rankine, however, with his usual discernment, at once perceived their correctness, and at the next session of the Institution pointed out that the simplest method of arriving at the differential equation of the ship's motion was to assume the figure of the wave to be trochoidal, instead of adopting the curve of sines hypothesis, whivh Mr. Froude had taken as the basis of his theory. This assumption, as Mr. Froude stated when speaking on Professor Rankine's Paper, was one which evidently led to a complete and rigorous solution of the whole question. We could have no better proof of the grand intellectual powers with which Professor Rankine was endowed than the fact, while Mr. Froude's theory was based in great measure upon experiment, his acceptance and emendation of it were dictated purely by theoretical investigations. Each succeeding year, Professor Rankine contributed to the Transactions of the Institution of Naval Architects some paper of importance to the shipbuilder or marine engineer, but these form only a small portion of his contributions to scientific knowledge.

It would be impossible, however, within the limits of this notice to refer even briefly to the whole of the subjects upon which Professor Rankine brought his powers of mathematical reasoning to bear so successfully. He perhaps acquired most fame by his contributions to the theory of thermo-dynamics, and by his reducing this to rules, easy of comprehension and adapted to the practice of engineers. His Manual of the Steam Engine is, indeed, the only book in the language in which this subject is treated exhaustively and at the same time in such a manner as to be practically useful. In addition to this work and the numerous papers from his pen to be found in the Transactions of the different learned societies, and in the columns of the Engineer, Professor Rankine was the author of exhaustive treatises on Civil Engineering and Applied Mechanics, besides being the principal contributor to Shipbuilding Theoretical and Practical, a well-known book published under his editorship.

Had he no other claims to distinction, the thoroughness with which he treated every subject he took up would have sufficed to have his name remembered; but it is by his rigid application of mathematics to the most abstruse branches of physical science that Professor Rankine will be best known, and it is this quality which makes his loss so difficult to repair.

He had been ailing for many months previous to his death, and though he had recovered sufficiently to take part in the meeting of the British Association at Brighton, last August, those who saw him there could not help observing that he was no longer his old self. Another serious attack of illness prostrated him again in October, but he once more seemed to regain his health, and his condition excited no great alarm until a few days before Christmas, when he rapidly lost power of speech and the sensibility of the right side. He never rallied, and his death occurred on Christmas Eve.

Naval Science Vol. II (1873), pp 259-260.

Transcribed by Lars Bruzelius

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Copyright © 1996 Lars Bruzelius.