66S SCIENCE PROGRESS 



matics who knows nothing about the psychology of his pupils is in a very unsatis- 

 factory position. It is unfortunate that progress in the technique of teaching 

 mathematics is so slow. But the number of people combining an interest and 

 competence in teaching and mathematical knowledge is very small. The book 

 under review is one of a few isolated attempts to draw a picture of the possi- 

 bilities in the technical development of mathematical teaching, when the 

 history of mathematics and the mathematical ideas themselves are presented 

 with due reference to the psychology of the learners. With an advance in 

 the technique at the disposal of researchers in psychological domains, and the 

 further development of the comprehensive modem hypothesis of the behaviour 

 of the mind, we may expect important results. The field when it is ripe for 

 scientific methods will be a most important one. In the meantime, the book 

 before us will doubtless be a stimulus towards some attempt at the develop- 

 ment of mathematical teaching on psychologically sound lines. 

 This edition contains a large amount of new material. 



D. M. Wrinch. 



Handbook o! Meteorology. By Jacques W. Redway. [Pp. 294.] (New 

 York: John Wiley & Sons ; London: Chapman & Hall, 192 1. Price 

 24s. net.) 

 This work is divided into two parts. In Part I the general facts of the meteor- 

 ology of North America are set out, together with sufi&cient theoretical physics 

 for a general understanding of the processes which give rise to everyday 

 weather ; Part II contains descriptions of instruments and observational 

 methods, the treatment of this subject being unusually thorough. In the 

 theoretical portions of the work there are good expositions of the formation and 

 importance of " lids " in the atmosphere, due to inversions of temperature, and 

 also of the part played by dust particles in cloud formation — the latter being 

 a field of inquiry in which the author has done original work. The causes of 

 precipitation are less clearly set out, and a correct idea of what has been 

 achieved in this subject is not conveyed. For instance, with reference to 

 unusually heavy falls of rain or "cloud bursts," after pointing out that the 

 atmosphere over any particular place probably never contains sufi&cient 

 water vapour to produce the rainfall observed on these occasions, it is 

 suggested that " a cloud-burst may be derived from the contents of a water- 

 spout carried inland for a long way and dumped upon the nearest mountain 

 crest which has a temperature low enough to chill it." There is, however, an 

 excellent chapter on cloud forms, abundantly illustrated by cloud photographs 

 taken by Dr. C. F. Brooks. 



As an introduction to meteorology for American students this handbook 

 should meet with success ; for English students it will be found wanting in 

 that the instruments described are often different from those in general use in 

 this country, while the remarks about weather prediction have little applica- 

 tion to the region of the British Isles. E. V. Newnham. 



Principles of Radio Communication. By J. H. Morecroft, Associate Profes- 

 sor of Electrical Engineering, Columbia University, assisted by A. 

 Pinto and W. A. Curry. [Pp. x + 935, with 788 diagrams and illus- 

 trations in the text.] (New York : John Wiley & Sons ; London : 

 Chapman & Hall, Ltd., 1921. Price 45s. net.) 

 An excellent general textbook of radio telegraphy and telephony containing 

 all the essential features of similar standard works, with much good additional 

 matter dealing with the modem phases of radio work. In accordance with 

 usual practice in books of this kind, the opening chapters deal with general 

 electrical considerations as far as they afEect the main subject, but they differ 

 from most such books in that the electron is considered as the viewpoint for 

 all purposes. The student is thus familiarised at once with modern thought 



