REVIEWS 165 



beginner, it is as disastrous to assume his complete ignorance of allied studies as 

 it is to commence at too high a level. This is particularly the case with such a 

 wide and embracing subject as Physics. 



Dr. Lownds's little book is quite a successful attempt as an introduction to the 

 study of elementary physical principles, dealing as it does with the prominent 

 facts of Heat — e.(^. thermometry, expansion, and change of state, and the general 

 introduction necessary for a qualitative acquaintanceship with these subjects. 

 The distinction between mass and weight might well have been omitted from 

 this elementary book. As an introductory first-year course the matter dealt with 

 here should be very suitable, and the use of this book would make unnecessary 

 a separate practical manual. 



Gregory and Hadley's book should serve readily as a continuation second- 

 year course. With the knowledge of general principles already gained, this 

 other volume, which deals more cursorily (perhaps too cursorily in places) with 

 the larger field of Heat, Light, Sound, Magnetism and Electricity, should prove 

 straightforward work. The section on light, which would be the first new subject 

 of the second-year course, is the best portion of the book, and the figures here are 

 particularly clear and instructive. The last part, dealing with electricity, could 

 have been, with advantage, entirely omitted and the space taken up with a little 

 more detail in the other branches. 



With this qualification, then, these two volumes should prove excellent company 

 as a two-years' course in elementary physics. Both are quite non-mathematical. 



J. C. Nixon. 



Physical Science in the Time of Nero, being a Translation of the Cluaestiones 

 Naturales of Seneca. By John Clarke, M.A. With Notes on the 

 Treatise by SiR Archibald Geikie, K.C.B., D.C.L., Sc.D., LL.D., 

 P.R.S. [Pp. liv -r 368.] (London : Macmillan & Co., 1910. Price lo^'. net.) 



The progress of science is at the present day so rapid that few have time to pay 

 much attention to the advancement in the past even of that particular branch 

 which specially interests them. Yet a knowledge of the lines along which any 

 science has advanced is likely to lead to some idea of the direction of the 

 continuation of those lines in the future ; furthermore, recognition of the causes 

 of the errors into which our predecessors have fallen may give us indication of 

 the pitfalls which we ourselves must avoid. 



The neglect of past history will be minimised if the specialist in research has 

 his task in studying it rendered easier, for few are able to advance their own 

 science in a conspicuous degree, and at the same time by study of original 

 authorities to summarise its progress in the past. There are, however, such men : 

 prominent among them is the President of the Royal Society, to whom the present 

 translation of Seneca's treatise owes its inception, to whom also the translator 

 is indebted for critical and explanatory notes. 



Seneca's work under notice is not a critical summary of Physical Science as 

 known at the time of its publication. " It was not his aim to compose a systematic 

 treatise on Natural Philosophy, but rather to take up some special subjects, and 

 deal with them in the light of what had already been written upon them, and of 

 what his own reflections suggested." The subjects dealt with appertain mainly 

 to the studies now known as Astronomy, Meteorology, and Physical Geography. 

 The book is incomplete ; but with all its imperfections it is of great value ; for, 



