1 78 PETER GUTHRIE TAIT 



do. Meanwhile I think we may tell Macmillan that the illustrations will in the main 

 be diagrams and not wood engravings (i.e. sketches) 



You see [from an enclosed letter] the information he wants as to advertising. 

 I wish you would give me a hint or two of your likings and dislikes on such a 

 delicate point. If we can settle on the nature of, and constitution of, our Preface, 

 I think a sort of precis of it would do very well for Advertisement. I think also 

 that we might begin even now to point out as looming in the future our Great 

 work, which so far as I know will be unique ; of course I mean the Principia 

 Mathematica, whatever be the title it is to bear. We may gain considerable credit, 

 and perhaps profit, by the present undertaking ; but the other will go over Europe 

 like a statical charge. Don't you think it would be prudent to warn the profane 

 off such ground by a timely notice? 



Such as this 



In preparation, by the same authors, 

 A MATHEMATICAL TREATISE ON NATURAL PHILOSOPHY, 



containing the elements of the mathematical treatment of Elasticity, Capillarity, 

 Electricity, Heat etc., etc., or anything tending to such a purpose.... 



A fortnight later (Jan. 20, 1862) Tait detailed to his Belfast friend 

 more concerning the coming book. In reply to a demand for information 

 regarding Heats of Combination, Andrews had referred to the discrepancies 

 between his measurements and those made a little later by Favre and 

 Silbermann ; and Tait replied in his turn : 



My immediate occasion for information on Heat of Combination (for my lectures) 

 is over, but I am sure Thomson and myself will have particular pleasure in putting 

 you right with regard to Favre and Silbermann, etc. But as matters are at present 

 arranged that will be in our second volume. I will give you here a short index of 

 the proposed Vol. I, with which we are busily engaged. I may merely tell you 

 that I don't feel any alarm on the point you mentioned in your first letter Thom- 

 son has thought far longer, and far more deeply, about matter than I have. 



The major part of the writing will be done by me as Thomson feels a repugnance 

 to it which is not common. I have already sent him two chapters, and a general 

 abstract of a section; and he speaks of them in the very highest terms.... 



Here we are, Vol. I. 



Section I. Chap. I. Introductory. 



II. Matter, Motion, Mass, etc. 



III. Measures and Instruments of Precision. 



IV. Energy, Vis viva, Work, 

 v. Kinematics. 



VI. Experience (Experiment and Observation). 



