66 Notices respecting New Books. 



We have thus noticed with some degree of particularity what we are 

 compelled to think weak points in Mr. Main's book, we may there- 

 fore with the more freedom express our sense of its many and great 

 merits. The mathematical part is executed with great elegance, and 

 with sufficient, though not too great fulness. This, together with 

 the clearness and brevity of statement exhibited in nearly every page, 

 renders it an admirable text-book, while Mr. Main's eminence as a 

 practical astronomer is sufficient guarantee that the book does 

 really " embody the practice and the theories of the present time." 

 We sincerely congratulate the Students in the Universities that 

 they have here (what they have so long wanted) a thoroughly good 

 text-book on this important and difficult subject. 



The First Principles of Natural Philosophy. By William Thynne 



Lynn, B.A., &c. Foolscap 8vo. pp. 100. London: Van Voorst, 



1863. 



There can be little doubt that the chief value of the study of 

 Physical Science, considered as an agent of general mental cul- 

 ture, is that it affords in a special degree the means of educating 

 the judgment, or the faculty of drawing correct general conclusions 

 from the particular facts of experience. It possesses this value, 

 however, only in so far as it is caused to be an exercise in the expe- 

 rimental method of inquiry, by which alone physical truths can be 

 discovered. In order that physical science may produce its full edu- 

 cational effect, the methods of studying it must be made to repro- 

 duce, as nearly as possible, the essential steps of the process of scien- 

 tific investigation. The physical facts should first be placed clearly 

 before the student ; he should then be made to see their mutual con- 

 nexion and dependence, and whatever regularities they present; 

 and thence he should be led up to the general law by which they 

 are governed. Afterwards should follow the converse process of 

 developing the consequences of the law thus arrived at, and apply- 

 ing the general expression to particular cases. To make the study 

 of Natural Philosophy consist of this latter part only, is to deprive it 

 of all that gives it any distinctive value as a study, and to reduce it 

 to a set of mathematical exercises, the solution of which, however 

 improving, can never impart any other discipline to the mind than 

 that which might be obtained from the solution of any other set of 

 problems involving the same mathematical operations. 



Nevertheless, as Natural Philosophy is, and doubtless will con- 

 tinue to be, thus taught, as merely a branch of Applied Mathematics, 

 teachers and students must be supplied with books wherein it is so 

 treated. Of books of this class, the one before us is a very favour- 

 able specimen. The author has confined himself to the most 

 fundamental points — the first principles — of the subjects treated 

 by him, and these he has succeeded in expounding, for the most 

 part very clearly, within very narrow limits. The work is di- 

 vided into five sections, respectively devoted to Statics, Dynamics, 

 Hydrostatics and Hydrodynamics, Pneumatics, and Optics, and it is 

 shown how the most important phenomena included under each of 



