September 23, 1922] 



NA TURE 



411 



senses have appreciated in simple yet delightful 

 language which cannot fail to awaken in his reader 

 that intense enthusiasm and love for Nature which he 

 himself undoubtedly feels. 



In this book Mr. Collett guides us pleasantly through 

 the year, pointing out the sign-posts which mark the 

 progress of the weeks and months : the awakening of 

 the spring, the arrival of the birds on spring migration, 

 the intense bustle and activity of the early months of 

 the year, the quieter and more matured beauty of 

 summer, the renewed activity of autumn with its 

 preparation for the winter, and the calm peace of the 

 winter months with always the promise of spring and 

 life. 



The book is full of useful facts and details which 

 only the true field naturalist can acquire and observe. 

 We regret that there is no index by means of which 

 ready reference to these first-hand observations can 

 be made. 



Radio Receiving for Beginners. By Rliey T. Snodgrass 

 and Victor F. Camp. Pp. 99. (London : Mac- 

 millan and Co., Ltd., 1922.) 35. 6d. net. 

 This is a work professedly intended for those with very 

 limited knowledge of wireless matters, but the author, 

 in his endeavour to avoid technicalities in the intro- 

 ductory portion, has rather missed the opportunity of 

 presenting the elements of the subject in a sufficiently 

 tangible form for the reader, if really unacquainted 

 with the principles of wireless working, to pick up 

 readily the full meaning of the excellent chapters which 

 follow. In these, we are conducted progressively 

 through crystal reception, plain valve reception, 

 regenerative working, and single and double valve 

 amplification. A good typical arrangement of con- 

 nexions is given in each case, but it is understood that 

 many variations can prove equally satisfactory. All 

 this part of the book is thoroughly practical, and its 

 utility is not greatly interfered with by the fact that it 

 refers to American conditions alone. The general 

 hints and the chapter on aerial construction are full 

 of useful points, and explanatory notes on some of 

 the individual pieces of apparatus which make up the 

 complete equipment are contained at the end. The 

 author makes it amply clear that wireless reception 

 requires care, skill, and practice to get really good 

 results, and is a good deal more than buying a complete 

 outfit and " listening in " with a telephone. 



Applied Calculus : An Introductory Text-book. By 

 F. F. P. Bisacre. Pp. xvi + 446. (London: Blackie 

 and Son, Ltd., 1921.) 105 6d. net. 

 The adjective " applied " is used by Mr. Bisacre to 

 imply " the treatment of practical problems being 

 preceded by a fairly full discussion of the necessary 

 theory." We thus get a competent elementary account 

 of the differential and the integral calculus, followed 

 by applications to curves, maxima and minima, 

 electricity and magnetism, chemical dynamics and 

 thermodynamics. The chapter on electricity and 

 magnetism is too short, while that on thermodynamics 

 is quite long. An attempt is made to clear up the 

 mystery of limits, but the success would be more 

 certain if the example used for the purpose were not 

 the rather trivial one of finding the limiting value of 



NO. 2760, VOL. I IO] 



x 2 when x becomes equal to 10. It is doubtful whether 

 " epsilonology " is at all in place in such a book, and 

 the practical student will scarcely be impressed with its 

 value in view of the author's treatment. The tables 

 should have been more extensive ; as they stand their 

 usefulness is very limited. 



Interesting features of the book are photographs 

 and biographies of pioneers in the calculus and its 

 applications. The mottoes at the heads of the chapters 

 are often cleverly chosen, like " A snapper-up of un- 

 considered trifles " for the chapter on integration. 



S. B. 



The Care of the Adolescent Girl : A Book for Teachers, 



Parents, and Guardians. By Dr. Phyllis Blanchard. 



Pp. xxi + 201. (London : Kegan Paul and Co., Ltd., 



1921.) 75. 6d. net. 

 In her foreword to this book. Dr. Phyllis Blanchard 

 explains that its object is to help teachers, parents, and 

 guardians to provide adolescents with definite informa- 

 tion concerning their own nature and to point the way 

 to a proper utilisation of their energies. 



After introducing the views of various authorities, 

 Dr. Blanchard considers the instincts of the adolescent 

 girl and the resulting conflict and repressions, and later, 

 the pathological results of these repressions. The most 

 important chapter is that devoted to the sublimation of 

 the sex factor into other activities. 



It appears that the author considers the adolescent 

 conflict as entirely sexual in nature ; but its solution, 

 which may be described as an adjustment to the 

 perpetual mate, is not the only one in which the 

 guardian and teacher must assist. The adjustment to 

 society, the failure in which gives us the recluse, the 

 crank, and the social rebel, is practically ignored. An 

 adjustment to the conception of the infinite, failure in 

 which leads to the conflict found in nearly all agnostics 

 and materialists, is only dealt with as a method of 

 sublimation of the sex factor ; from this point of view 

 the author evolves a Christianity which, as Dr. Scharlieb 

 states in her preface, is scarcely to be recognised as 

 Christianity by those who have been brought up in any 

 of the orthodox schools. 



Hyperacoustics. By John L. Dunk. Division II. 



Successive Tonality. Pp. xi + 160. (London : J. M. 



Dent and Sons, Ltd, ; New York : E. P. Dutton 



and Co., 1921.) 55. net. 

 The first division of the author's work, " Simultaneous 

 Tonality," was published in 1916 and was shortly 

 afterwards reviewed in these columns (vol. 98, p. 306, 

 December 21, 1916). At least one-third of the present 

 volume is devoted to a " brief resume " of the earlier 

 book, and then the author passes on to the new aspect 

 of his subject, " Successive Tonality." The method 

 of treatment is similar to that adopted previously, 

 and there is little to add to the notice of the first 

 volume. The nomenclature is so complex that a 

 glossary, occupying six pages of the text, is provided 

 for the convenience of the reader. The author recog- . 

 nises the difficulty clearly : " The jargon of each 

 particular science is a real obstacle, not only to the 

 acquisition of knowledge, but to the sympathetic 

 understanding by workers in parallel fields, who, 

 occupied with their own formulae, tend to be repelled 



