96 THE LIFE OF JAMES D. FORBES. [CHAP. 



want a fit text-book I mean for theoretical mechanics. 

 Notwithstanding the number of works on the subject, 

 without, I hope, being fastidious, which my qualifications 

 do not entitle me to be, I have found no work to my 

 mind. ... In writing on a subject so vitally important, 

 I need not assure you that compliment is wholly foreign 

 to my thoughts, when I state that your Mechanics has 

 appeared to me far the best book I have met with for 

 teaching from, both from its admirable arrangement, 

 which I have hitherto almost strictly followed in writing 

 my lectures, its mixture of geometry and analysis, its 

 subdivision into clear propositions and illustrations. But 

 for my purpose it is too long : it is, on the whole, rather 

 too difficult. 



' What I want you to be prevailed upon to do is to 

 publish a sort of abridgment of the work requiring a 

 grade less mathematics, and introducing into the dyna- 

 mical part problems from your new Introduction to 

 Dynamics, which, by the way, I mean to teach at a 

 separate hour to more advanced students. I would have 

 nothing farther than the very elements of the calculus, 

 and that part printed in a smaller type. . . . Your 

 labours are most properly devoted to your own noble 

 institutions; nor would I venture to ask you to do 

 anything which would employ much time. Such a text- 

 book as I want would be almost composed by the easy 

 art of clipping from your own writings, and if you would 

 add a short system of Hydrodynamics, it would be an 

 important addition. The whole should not exceed 300 

 pages octavo, as I can hardly devote three months of 

 my course to it/ 



One cannot but wonder at the boldness with which 

 this youth of three-and- twenty approaches the great 

 Cambridge Don, one of the chief scientific celebrities of 

 the time, to lay upon him so exacting a demand. It is 

 still more surprising to find the Master of Trinity 

 quietly submitting, and setting himself to execute the 

 imposition. 



From time to time, during the preparation of his 



