SotfCi's respectuKj yew JJooks, 'd<il 



It is unnecessary to refer in these days to the great importance of 

 Green's work in the theory of the potential. G-reen's theorem is 

 the great touchstone of transformation in mathematical physics ; 

 and the papers on the EeHexion and Kefraction of Light and on 

 Double Refraction are of the highest interest. 



Dif)U(mics of BotafioH, an eUm-ititar)! introduction to rlrjid di/namics. 

 B)f A. M. AVoRTiiiXGTON. Fourth Edition. Longmans, Green 

 .^-^ Co. 



This is an admirable little book and should be in the hands of all 

 teachers of dynamics. Elementary dynamics should certainly be 

 extended to take in some of the simpler theory of the motion of 

 real bodies. When a boy sees how much can be done in applying 

 simple dynamical reasoning to the familiar motion of a top he will 

 begin to have some regard for the subject. The one essential is 

 for the student to get a true idea as to the meaning of moment of 

 momentuQi, and to see clearly that its rate of change measures the 

 acting couple. The quaternion aspect of the subject is specially to 

 be commended, and might, we think, have been introduced more 

 explicitly into the discussion. Once this great theorem is grasped, 

 many of the problems of spinning tops and bicycle balancing are 

 solved by inspection, at least in a qualitative sense. As an intro- 

 duction to the study of the dynamics of extended rigid bodies, there 

 is, we venture to think, no better book in our language, if indeed 

 in any language. 



Lehi'bucJi der Physlk. Von 0. D. Chwolsox. Vol. I. Translated 

 from the Russian into German bv H. PHaum. Braunschweig : 

 1\ Yieweg und Sohn. 1902. 



This book by the well-known St Petersburg physicist is issued 

 with a short commendatory note by Professor Wiedemann, 

 with whom the idea originated to bring the book into wider cir- 

 culation by means of a German translation. This first volume is 

 divided into six parts, a brief introduction being followed by nine 

 chapters de\'otecl to Mechanik (practically our dynamics). Then 

 we have nine chapters on measuring-instruments and the way to 

 use them. The fourth part (of six chapters) considers the pro- 

 perties of gases, the fifth part, with ten chapters, the physical 

 properties of liquids, and finally the sixth part the doctrine of rigid 

 b jdies, including crystallization, elasticity, friction, and impact. In 

 all these sections the effects of change of temperature are freely 

 introduced, a sutlicient exposition of the principles of thermometry 

 in the introductory chapter making this possible. The mode of 

 treatment is essentially experimental, although the elementary 

 processes of differentiation and integration are used when 

 necessary. An unusual feature is the introduction into the 

 general chapter on wave-motion of a discussion of the principle of 



