226 PETER GUTHRIE TAIT 



expounding other people's discoveries as if they were his own. Boyle, no 

 doubt, was an Englishman ; but it cannot be claimed that Marriotte preceded 

 him. There is no Chauvinism here on Tait's part. On the other hand it was 

 Tait, who, accepting the statement of Gay-Lussac, secured for "le Citoyen 

 Charles " the recognition of his rights in relation to the law of gases, named 

 after Dalton in this country and after Gay-Lussac on the Continent. It was 

 Tait more than any other individual writer who popularised Carnot's Cycle 

 of Operations and the Perfect Engine, which are expounded not only in his 

 purely scientific works but also in The Unseen Universe. Again, Tait, by 

 translating Helmholtz's paper on Vortex Motion, gave a new direction to 

 hydrodynamical study in this country. No doubt he felt warmly any attempt, 

 conscious or unconscious, to credit to others discoveries made by any of 

 his own countrymen, and in this he was not peculiar ; but I know of no case 

 in which he claimed for a fellow countryman anything which could be 

 demonstrably associated with the name of another at an earlier date. He 

 used to say that, if laws are to be named after their first discoverers, then 

 Ohm's Law should be called after Fourier, and Doppler's Principle after 

 Romer. In these instances there is nothing Chauvinistic. 



There are now many books on Thermodynamics of various standards, 

 each having its own merit. But as an account of the fundamental principles 

 in their historic setting Tait's Sketch cannot be surpassed. The promi- 

 nence given to Carnot's Principle, the simplicity and directness of the 

 mathematical methods introduced into the third chapter, the beautiful illus- 

 trations of the transformation of energy given in the second chapter, and the 

 clear account of the manner in which Thomson seized hold of the original 

 conception of absolute temperature, all give the book a character peculiarly 

 its own. Abbe" Moigno, the well-known mathematician and editor of Les 

 Mondes, saw at once the value of the work, and with the help of M. Alfred 

 Le Cyre, published a French translation in 1870. The preface opens with 

 these sentences : 



" Lorsque je lus pour la premiere fois 1'Esquisse historique de la the'orie dynamique 

 de la chaleur, trois choses me frapperent vivement : i, 1'auteur resume rapidement et 

 completement les travaux accomplis dans cette branche aujourd'hui si tendue de la 

 physique mathematique ; 2, il rend parfaitement & chacun la justice qui lui est due ; 3, 

 il etablit en quelques pages tres-nettes et tres-ele"gantes synthetiquement d'abord, analy- 

 tiquement ensuite, les lois fondamentales de la dynamique de la chaleur." 



The next work by Tait which calls for notice is his Recent Advances in 

 Physical Science (Macmillan & Co., 1876, 2nd Edition, 1876), the published 



