MAXWELL'S REVIEW OF "THERMODYNAMICS" 221 



"Prof. Tait has not adopted either of these methods. He serves up his strong 

 meat for grown men at the beginning of the book, without thinking it necessary to 

 employ the language either of the nursery or of the school ; while for younger 

 students he has carefully boiled down the mathematical elements into the most 

 concentrated form, and has placed the result at the end as a bonne boucJu, so that 

 the beginner may take it in all at once and ruminate upon it at his leisure. 



"A considerable part of the book is devoted to the history of thermodynamics, 

 and here it is evident that with Prof. Tait the names of the founders of his science 

 call up the ideas, not so much of the scientific documents they have left behind 

 them in our libraries, as of the men themselves, whether he recommends them to 

 our reverence as masters in science, or bids us beware of them as tainted with 

 error. There is no need of a garnish of anecdotes to enliven the dryness of science, 

 for science has enough to do to restrain the strong human nature of the author, 

 who is at no pains to conceal his own idiosyncrasies, or to smooth down the 

 obtrusive antinomies of a vigorous mind into the featureless consistency of a con- 

 ventional philosopher." 



The succeeding paragraphs contained a masterly account of the scientific 

 methods of Rankine, Clausius, and Thomson. 



In this bonne bouche of a third chapter, as Maxwell humorously 

 called it, Tait gives an extremely compact and instructive sketch of the 

 mathematical elements of the subject. Beginning with Watt's energy diagram 

 he developes Carnot's cycle in its modern form, and then, possibly following 

 Maxwell's advice quoted above, discusses with great clearness Thomson's 

 scale of absolute temperature. With this in hand and with the further 

 assumption based on experiment that Carnot's function is inversely as the 

 absolute temperature, Tait is able to present Thomson's original treatment 



in a simplified form. When, however, Tait explicitly referred to , -j- as 



" Thomson's expression for the amount of heat dissipated during the cycle " 

 Clausius found cause of complaint, claiming the above integral as his. In 

 the preface to the second edition Tait showed very clearly that Thomson 

 had the whole thing formulated as early as 1851 ; but not until he and Joule 

 had experimental evidence of the value of Carnot's function would Thomson 

 use any other than the unintegrated form with the symbol p for Carnot's 

 function. 



In a postcard of date Feb. 12, 1872, Maxwell remarked: 



"As for C., though I imbibed my Acs from other sources, I know that he is 

 a prime source, and have in my work for Longman been unconsciously acted on 

 by the motive not to speak about what I don't know. In my spare moments 

 I mean to take such draughts of Clausiustical Ergon as to place me in that state 



