682 SCIENCE PROGRESS 



exercises are grouped according to their difficulty, some are as direct as possible 

 and bear on main principles, others are similar to those carried out in the most 

 elementary experiments, and others bear on more advanced practical methods and 

 recent work. There are also a number suitable for more advanced students. The 

 collection is very complete, and the questions are concrete and real. Frequently 

 they suggest to the intelligent student methods of practical work which are not 

 referred to in the average text-book. Short preparatory paragraphs on theory 

 and a number of worked examples precede each section of the book. 



(b) This excellent little book ought to be in the hands of every teacher. While 

 the simple principles are introduced and treated in a logical and consistent manner, 

 the problems are not of that abstract and remote type so common to the general 

 class book of Mechanics. There is no reason why the graphical methods which 

 the engineer uses to solve his problems should not be used by even a beginner. 

 This book shows how such methods can be applied in a simple way to those 

 questions which every experience of our daily life raises. When a student sees 

 how graphical methods can be applied with ease to the roof of the house in which 

 he lives, the bicycle on which he rides, and the bridge over which he walks, he 

 forms a much more correct idea of the utility of Mechanics than he does after the 

 usual school course in which he slips down " perfectly smooth " planes or drowns 

 in " perfect " liquids. 



This second part extends the application of the principles discussed in Part I. 

 Frameworks are treated by graphical and analytical methods, Bow's notation 

 being introduced and explained. This leads to a short account of chains and 

 suspension bridges. The treatment of couples is illustrated by bending moments 

 and shears. Nothing indicates the tone of the book better than the fact that 

 such an everyday occurrence as the jamming of a drawer is used to exemplify 

 the laws of friction. Last, but not least, the student realises that the world 

 has three dimensions, and he is no longer compelled to live " in the plane 

 of the paper " following innumerable " uniformly accelerated " bodies along their 

 interminable straight paths. 



(c) This book is substantially Parts I, II, and III of the Class Book of Physics, 

 by the same authors, with many of the sections extended and a number of additions. 

 It is written to supply the need for a single text-book on Mechanics and Heat 

 suitable to the standard required in certain public examinations in which these 

 two subjects are taken together. 



The book is up to the standard already attained by previous works of the 

 authors, and is adequate for the purpose referred to. The text is clearly written 

 and covers considerable ground, while the examples are representative and well 

 chosen. It seems a pity that a more complete account of curvilinear motion is not 

 introduced into Chapter VIII ; graphical methods can be applied with such ease 

 to curvilinear motion that the omission of a full treatment of it from the average 

 elementary text-book forms a serious defect. Many a boy can solve the most 

 intricate puzzles on " falling bodies " and yet be perfectly ignorant on the subject 

 of walking round a street corner. 



J. Rice. 



The Mathematical Analysis of Electrical and Optical Wave-Motion on the 

 Basis of Maxwell's Equations. By H. Bateman, M.A., Ph.D. [Pp. vi + 

 159.] (Cambridge : at the University Press. Price 7s. bd. net.) 



Thk average student who graduates in Physics has, as a rule, sufficient mathe- 

 matical equipment to follow the deduction of the equations of the electromagnetic 



