395 



NA TURE 



[February 3, 1910 



ferable to have substituted the description of a stickle- 

 back for that of a pike in the fauna of the pond as 

 being more characteristic. We should think it rather 

 doubtful whether most children (or grown-ups) would 

 identify the frontispiece of the first of these two books 

 as a hedge, nor should we wish the statement on p. 

 32 of the same book, that the "sap escapes and takes 

 the form of curiously moss-like growths," to be taken 

 as scientifically accurate by the student of natural 

 history. 



(4) Who could describe the butterflies to our children 

 better than the Rev. Theodore Wood, who has done 

 so much to popularise natural history among the 

 young? We should expect that he would do it ex- 

 cellently, and are not disappointed in this little book, 

 which is one of the best of the series. With the ex- 

 ception of one or two of the caterpillars, the illustra- 

 tions are e.xcellent, as is essential in a book of this 

 nature, where a good coloured figure is so important ; 

 for no child could identify a butterfly correctly and 

 with ease from the best of written descriptions. 



(5) In describing the eggs of birds to the children 

 it is an e.xcellent idea to associate the nests with 

 the eggs. Children do not dissociate the two to the 

 extent that many older persons in the past have been 

 accustomed to do. To a child as yet unspoilt by the 

 collecting fever characteristic of youth, the nest is as 

 important as the eggs it contains, and this small 

 book will serve as an excellent guide to those budding 

 observers to whom the finding of a nest is an object of 

 interest and pleasure. 



(6) .Strictly speaking, this book, which is a collec- 

 tion of tales of the backwoods of Canada, does not 

 come within our province; nevertheless, the author is 

 so keen an observer of nature, and so well known as 

 an ardent follower of the "call of the wild," that some 

 of his tales are full of life and interest, and form 

 excellent " light reading." 



C. Gordon Hewitt. 



OUR BOOK SHELF. 

 Recent Advances in Physical and Inorganic Chemistry. 

 By Dr. A. W. Stewart. With an Introduction 

 by Sir Wm. Ramsay, K.C.B., F.R.S. Pp. .xiv + 267. 

 (London : Longmans, Green and Co., 1909.) Price 

 75. 6d. net. 



The present volume is a companion to the author's 

 book entitled "Recent Advances in Physical 

 Chemistry." The issue of two surh books by the 

 same author affords a fair gauge alike of their merits 

 and of their demerits. At the present time, no one writer 

 can possibly be a master of organic, of inuiiranic, and 

 of physical chemistry, and the criticisms that arc offered 

 by the author cannot, therefore, be regarded as having 

 more than a superficial value. On the other hand, 

 the production of a second volume so soon after the 

 publication of the first may be taken as evidence of 

 a considerable popular demand, and shows at least 

 that a book of this type was called for by a wide 

 circle of readers. In the circumstances, it is to be 

 regretted that the publishers did not follow out the 

 plan they have adopted in their excellent "Text- 

 books of Physical Chemistry " and in their " Mono- 

 graphs on Biochemistry " of securing a series of 

 articles by authors who have themselves worked on the 

 subjects which they discuss. A volume compiled on 

 NO. 2IOI, VOL. 82] 



these lines would have been of real value and 

 undoubted usefulness. 



In the present instance the author has rendered a 

 service to the student who is working for an honours- 

 degree by presenting in a compact form the main- 

 results of certain lines of research which have been, 

 carried on in recent years, and may from time- 

 to time form the subject of examination ques- 

 tions. These investigations can only be mastered by 

 a toilsome perusal of the original hterature, and every 

 attempt to reduce the labour involved in this task is- 

 sure of a welcome alike from the student and from- 

 the teacher. The danger of all such attempts is that 

 the reader may acquire the indolent habit of obtaining" 

 his information in this easy way from second-hand 

 sources, and so lose the stimulus and the opportunity 

 of independent judgment which come from a perusal 

 of the original text. On the whole, however, if the- 

 work is adequately carried out, the balance of advan- 

 tage is in favour of the method of summarised presen- 

 tation, and as the bulk of chemical literature becomes 

 more and more unwieldy, the production of these 

 summaries will become increasingly important. On 

 these lines. Dr. Stewart's volume may be sure of a 

 welcome and a considerable circulation. 



(i) The Elements of Mechanics of Materials. A Text- 

 book for Students in Engineering Courses. By 

 C. E. Houghton. Pp. viii + 186. (London: Con- 

 stable and Co., Ltd., 1909.) Price 7*'. 6d. net. 

 (2) Experimental Mechanics for Schools. By F. 

 Charles and W. H. Hewitt. Pp. vii + 288. 

 (London : G. Bell and Sons, 1909.) Price 3s. 6d. 

 (i) In this elementary text-book the engineer- 

 ing student is provided with a clear and concise 

 account of the practical applications of mechanical 

 principles to the design of simple machine parts and' 

 common structures. The first two chapters deal with- 

 the properties of materials as disclosed in the experi- 

 mental laboratory, and with the strengths of tie-rods, 

 cylinders, and riveted joints. Succeeding chapters- 

 relate to the strength and stiffness of beams, shafts,. 

 struts, and composite structures, including reinforced 

 beams and columns ; there is also an investigation 

 of the effect of combined stresses. The most valuable- 

 parts of the book are the excellent collections of review 

 questions and illustrative problems with which each 

 chapter closes. These are very suggestive, well 

 graduated, and eminently practical, and will be 

 greatly appreciated by students and teachers alike. 

 The author writes for those students who have only 

 time for a very cursory study of the theory of elas- 

 ticity, so that the limitations of the various formulas 

 are scarcely considered. The book will serve a very 

 useful purpose, and will afford great assistance ir» 

 some parts of practical design. 



(2) Messrs. Charles and Hewitt describe or suggest 

 a large number of simple experiments illustrating the 

 principles of mechanics, and give extensive sets of 

 examples in which these principles are enforced and 

 applied. They constitute a mine from which 

 teachers may select such details as are suitable for 

 their own particular circumstances. The earlier 

 experiments are statical, and deal with forces at a 

 point, parallel forces, and friction, and illustrate the 

 principle of the parallelogram and of the lever. A 

 boy easily understands the action of a force because 

 he employs his muscles every day to exert forces. 

 The actions of couples remain more or less of an 

 abstraction, for he seldom applies them. The authors 

 have overlooked the need there is in the laboratory for 

 the frequent muscular application of torques, 

 measured bv angular displacements in a simple torque 

 meter placed between the hand and the apparatus. 



