I30 



NATURE 



[June 9, 1892 



In his private engineering practice at Belfast, he 

 carried out important work in hydraulic machinery for use 

 at home and in foreign countries. He invented the 

 inward flow vortex turbine, and even now there are men 

 in Ulster who are willing to talk at great length about his 

 troubles and successes with this turbine. There was no 

 practical man, however clever, who did not at first 

 ridicule the scientific young gentleman who proposed to 

 replace an eighty foot wheel by a tiny turbine, whose 

 wheel was less than a foot in diameter. He never in his 

 life could have had a happier moment than that in which, 

 surrounded by crowds of astonished rustics and practical 

 engineers, he saw this tiny wheel in its very first trial, 

 driving the machinery of a large mill. And now, 

 wherever turbines are to be found all over the world, they 

 are mostly " Thomson " turbines, made on the principles 

 so clearly thought out and described by him, albeit they 

 are known under many very different names. His notions 

 on such subjects as strength of materials and the effect of 

 initial strains in materials, although published forty-four 

 years ago, have only lately become the notions of 

 practical engineers. At that early date, his ideas on 

 many of the applications of science in engineering were 

 very clear and correct, and far in advance of his contem- 

 poraries. He is especially to be recognized for his services 

 in practical hydrodynamics, a subject in which there has 

 been a more misleading appearance of mathematical 

 theory than in any other branch of engineering. To one 

 of Thomson's pupils it is positively painful to take up any 

 authoritative treatise on hydraulic machinery, for he 

 knows that nearly every page of troublesome mathematical 

 reasoning is based on some absurd assumption, and that 

 James Thomson's few propositions are almost the only 

 ones on which the engineer can rely. James Thomson 

 seemed to fear the misuse by young engineers of the 

 recognized mathematical methods of attacking physical 

 problems. He, himself, when he used mathematical 

 expressions, used them merely to put before others the 

 results of his own method of reasoning. It expresses 

 only a part of the truth to say that he thought about 

 things geometrically rather than algebraically. He 

 refrained from publication until his proof was perfect, 

 and some of his pupils may feel sorry that they have not 

 more faithfully followed their master's example. A study 

 of his successive manuscript proofs of his law of flow of 

 fluids from similar orifices would probably enable us to 

 conceive of the habits of thought of the Greek geometers : 

 every word and phrase is carefully selected, and con- 

 sidered time after time with a view to perfect accuracy. 

 Such invention and such regard for perfection of detail 

 were surely never combined before. 



When any of his speculations has been once published 

 in an authoritative text-book, it will be noticed that it ap- 

 pears in all text-books published subsequently ; the melt- 

 ing point of ice, the triple point in water-stuff, the 

 continuity in the steam water isothermal, the tears of 

 strong wine, are a few examples. No doubt, as time 

 goes on, text-book writers will find that he discovered 

 other important things. He was such a very observant 

 man that he often put forward his most important pro- 

 positions when • explaining phenomena that seemed 

 utterly insignificant. Let the reader only think that what 

 occurs in a wash-basin, or in a little rivulet near the sea, 

 may be of great importance scientifically, and let him 

 read again some of Thomson's insignificant-looking 

 scattered papers, and he will find important propositions 

 published which will not, perhaps, for some years yet, 

 find their proper positions in the text-books. 



Of the history of thermodynamics during the event- 

 ful years 1849-50, who dares now to say anything ? Nor 

 can anyone now say anything about the great glacier dis- 

 pute. One thing is certain, however, that James 

 Thomson's discovery of the necessary lowering of the 

 melting-point of ice with pressure, published on January 



NO. 1 1 80, VOL. 46] 



2, 1849, settled for ever the theory of the flow of glaciers. 

 Joule's work was beginning to be known, but Thomson, 

 in his proof, like Lord Kelvin in the well-known paper 

 published on the same day, adopts Carnot's idea of the 

 conservation of heat. A change in one expression, not 

 essential to the proof itself, was all that was needed after 

 the first and second laws of thermodynamics had been 

 recognized. Of his various papers on hydrodynamics, 

 capillarity, heat, light, and the states of matter, pub- 

 lished since that time, we have not space to say more 

 than that each of them made a substantial addition to 

 our knowledge. His latest work, the Bakerian Lecture 

 this year of the Royal Society, on " The Grand Currents 

 of Atmospheric Circulation," is such a paper as we might 

 expect from a man who had given more than thirty-five 

 years of study to the subject, that subject being one which 

 was peculiarly his own. It is possible that the practical 

 engineer, judging from the title merely, may neglect to 

 read a paper which is one of phenomenal importance to 

 the engineer as well as to the physiographer. 



He was a man of singular purity of mind and simplicity 

 of character, very clear-sighted in all that pertained to 

 moral right and wrong, and conscientious to a degree. In 

 his presence one felt in a purer atmosphere, where mean 

 things seemed impossible. No Professor was ever so 

 willing to take trouble (not mere momentary trouble, but 

 trouble of days and nights) in the interests of a student, 

 but no Professor was ever so rigidly exact in giving cer- 

 tificates and testimonials. The present writer has talked 

 often with his old pupils about him, but never met one 

 of them, who, besides a great respect, had not also a 

 genuine and kindly and pleasurable love for his old 

 Professor, whose kindness and patience had beenunfaiHng, 

 and whose sympathy had many a time been extended 

 to him. How useless it is to speak of the good done to the 

 world by a man of his character. Every one of his 

 pupils, in however small or great a degree, is extending 

 the range of his influence. 



JEAN SERVAIS STAS. 



THE regret expressed in the obituary notice of Jean 

 Servais Stas, that we had not the exact words 

 of his famous discourse delivered before the King of the 

 Belgians, has attracted the attention of a correspondent, 

 who has very courteously sent us the text of the speech. 



It was delivered by J. S. Stas in his capacity of Pre- 

 sident of the Royal Academy of Sciences, and was 

 addressed to the King at the New Year's reception, 

 January i, 1891. We have much pleasure in laying a 

 translation of it before our readers : — 



" Sire, 



" The Royal Academy of Science, Literature, and 

 the Fine Arts expresses its sincere wishes for the happi- 

 ness of your Majesty, and the prosperity of your reign. 



" As the central organ of the intellectual movement of 

 the country, the Academy seeks to comprise within its 

 arms the most varied talents, and to remain always an 

 adequate and living expression of the entire activity of 

 the human mind. 



" This is both its duty and the reason for its existence. 



" In the sphere of Literature and Art its voice is almost 

 always safely guided by public opinion— a competent 

 judge of works accessible to all. 



" It is otherwise in the sphere of Science. 



" The physical, mathematical, and natural sciences, and 

 even the moral and political sciences, do not appeal in 

 the same degree to public opinion. If their conquests 

 radiate afar, if they incessantly modify the conditions of 

 social existence, they themselves develop in restricted 

 circles, and work out of sight and of knowledge of the 

 multitude. 



