Notices respecting New Boohs. 383 



Greece, United States of America, some parts of Asia, Algeria, 

 Tunis, and Egypt are also given. 



This work is an excellent model for wbat might be done with 

 advantage by geologists and architects in other countries : indeed 

 Dr. Karrer intimates that England in particular could produce, and 

 decidedly requires, such a Guide-book, having reference to the 

 local museums, quarries, and great buildings, whether public or 

 private works. 



The exquisitely neat and truthful reproductions of the many 

 architectural photographs used in illustrating this Guide-book 

 greatly enhance its value both for the general reader and the con- 

 noisseur of stone-work. A long list of corrections is supplied ; 

 and a very full and useful Index of things, places, and names 

 occupies the last fifty pages. 



Dynamics of Rotation. By A. M. Worthington, M.A., F.B.A.S. 



London : Longmans, 1892. 

 In the ordinary text-books of Elementary Mechanics and Dynamics 

 of a Particle the subject of rotational motion is, as a rule, treated 

 with extreme brevity, and is sometimes entirely neglected. Con- 

 sequently a student who has made himself quite conversant with 

 the principal facts relating to motion of translation often meets 

 with great difficulties on commencing a course of Rigid Dynamics, 

 arising mainly from his want of familiarity with the properties of 

 couples and the phenomena presented by a spinning body. In 

 addition to this the examples and problems in treatises on Rigid 

 Dynamics usually involve motion in three dimensions, and a know- 

 ledge of solid geometry is required for their solution. The aim of 

 the present book is to introduce the student a little more gradually 

 into the intricacies of the subject of rotation, by confining his 

 attention at first to problems involving motion about a single fixed 

 axis. The laws of such motion lead up to the definition of a 

 moment of inertia, and a considerable portion of the book is 

 devoted to the methods of finding moments of inertia and the 

 various theorems respecting them. The subject of oscillations 

 then comes in for a share of attention, after which the laws of 

 conservation of angular momentum and of the independence of 

 translation and rotation are enunciated and applied. The book 

 concludes with an interesting chapter on the phenomena of pre- 

 cession. The aim of the author has been throughout to treat the 

 subject from a physical rather than a mathematical standpoint ; 

 and wherever possible he has appealed to experiment to illustrate 

 and confirm the mathematical investigations. We learn from the 

 preface that the book is intended for those students of Engineering 

 or Physics who have not a sufficient knowledge of mathematics to 

 enable them to follow the works of mathematical writers on Rigid 

 Dynamics. Eor such it should prove useful, but it will be of some 

 service also to the mathematical reader, by giving him clearer ideas 

 as to the physical meaning of the equations which he uses. 



James L. Howard. 

 2D2 



