396 



NATURE 



[February 4, 1909 



quite a paucity of investig'ation into its features and 

 effects. Most text-books on hydraulics content them- 

 selves with merely a passing reference, and make no 

 attempt to elucidate any of the interesting and practical 

 problems suggested by the subject. This omission 

 Mr. Gibson has sought to make good by the publica- 

 tion of the results of a series of useful experiments 

 which he has carried out in the engineering labora- 

 tories of Manchester University. 



The experiments were made with the object of deter- 

 mining the actual rise and fall of pressure in a pipe 

 line due to the gradual, or sudden, closing, or opening, 

 of a valve. For this purpose a cast-iron pressure main 

 was used, of 3J inches diameter, 560 feet in length, 

 conveying water from an elevated tank, 107 feet above 

 the laboratory floor. The results of four series of ex- 

 periments are graphically represented, and these and 

 other observations are tabulated in comparison with 

 theoretical values obtained from a formula the con- 

 struction of which is fully explained. 



Mr. Gibson takes his subject-matter a step further, 

 and includes a very useful little chapter dealing with 

 the application of the principles established to the 

 theory of turbine regulation. Altogether, this small 

 volume is an exceedingly welcome recruit to the ranks 

 of original experimental research literature in a branch 

 of natural science which itself is of the greatest prac- 

 tical value to mankind. 



Valve-gears for Steam Engines. By Prof. Cecil H. 

 Peabody. Second edition, revised. Pp. vi+142. 

 (New York : John Wiley and Sons ; London : 

 Chapman and Hall, Ltd., 1906.) Price los. bd. 

 net. 



This book is intended to give engineering students 

 instruction in the theory and practice of designing 

 valve-gears for steam engines. Prof. Peabody has 

 dealt with the subject in his usual able manner, and 

 his methods are most lucid. The volume is divided 

 into six chapters, with a good appendix. Graphical 

 methods are used throughout, and the plates at the 

 end of the book are remarkably clear. 



The Stephenson link motion is dealt with in 

 chapter iii. This gear has been so long in use that 

 finality might be expected in locomotive practice as 

 regards the correct lead of the valve in full gear; 

 yet this is not the case. The late Mr. William 

 Stroudley was a strong advocate of no lead in full 

 gear, and he obtained remarkable results from his 

 locomotives; others, again, follow the reverse prac- 

 tice. 



Chapter iv. deals with the verv interesting subject 

 of_ radial valve-gears, of which, of course, the 

 Walschaert is best for locomotive purposes, and is 

 now being largely used in America in preference to 

 the Stephenson gear. Continental practice having 

 long adopted this course. 



This is a revised second edition of the book, and 

 the few changes that have been made have been in 

 the right direction. We can truly recommend the 

 work to all draughtsmen and engineers who have to 

 deal with the interesting and intricate questions 

 which arise when designing valve-gear. 



Tlte Btdl of the Kraal and the Heavenly Maidens, 

 a Tale of Black Children. By Dudley "Kidd. Pp. 

 .\ii+302. (London : A. and C. Black, 1908.) 

 Price 6s. 



Mr. Kidd in his earlier works, " The Essential 

 Kafir" and "Savage Childhood," exhibited an 

 intimate knowledge of the social life of the Bantu 

 race. The present book is more popular, being in- 

 tended to describe a series of typical incidents in the 

 life of a little boy. Mahlek'a, the " Bull of the 

 NO. 2049, VOL. 79] 



Kraal," is the son of the Great Wife of the tribal 

 chief, and his heir-apparent. In sketches of this 

 kind, the work of a sympathetic observer of a semi- 

 savage people, there is the risk, on the one hand, of 

 assuming that any foreigner can fathom the deeper 

 recesses of the native mind. On the other, there is 

 the danger of dwelling on their virtues and ignoring 

 the darker side of the native character. Mr. Kidd 

 seems hardly to have avoided both these pitfalls. He 

 sometimes reads into the mind of the Bantu child 

 ideas foreign to it, and his account of the simple life 

 in the kraal neglects the treachery and ruthless 

 ferocity of the Zulu, which it is never safe for the 

 white man to forget. 



With these reservations, his story of this little Zulu 

 boy is both amusing and instructive. The careful 

 account of the games of children will be of value 

 for the comparative study of the subject. The folk- 

 talcs collected by Mr. Douglas Wood in south-eastern 

 Rhodesia are, on the whole, disappointing, and con- 

 tain little new incident. More valuable than these 

 are the scraps of folk-lore which the author loses 

 no opportunity of retailing. Particularly interesting 

 are the illustrations of sympathetic magic. Thus, 

 when a child's hair is cut it is buried in damp soil to 

 make it continue growing; rain-medicine is made out 

 of porpoise flesh, and so on. 



The value of the book is much increased by the 

 drawings of kraal life by Miss A. M. Goodall, which 

 are artistic and well selected. 



Fruit Trees and their Enemies, with a Spraying 

 Calendar. By .Spencer \J . Pickering, F.R.S., and 

 Fred. V. Theobald. Pp. 113. (London : Simpkin, 

 Marshall, Hamilton, Kent and Co., Ltd.) Price 

 IS. 6d. net. 

 This little book is written for the guidance of fruit- 

 giowers, perhaps the most intelligent and enterprising 

 of all those who live by the cultivation of the soil. 

 Although spraying has only come into use in England 

 during the last few years, it has been taken up with 

 great enthusiasm; unfortunately, however, the prac- 

 tical man has been in many cases without adequate 

 scientific guidance, and has been left to the mercv 

 of the enterprising advertiser. 



The various insect and fungoid pests are described, 

 and brief notes on their life-history are given. Their 

 effect on the fruit or tree is then stated, so that the 

 practical man may have no difficulty in recognising 

 with what he has to deal: finally, recipes are given 

 for making up the appropriate wash. The instructions 

 are clear, and the practical man should have no diffi- 

 culty in following them. Some of the washes will be 

 new to many growers ; they have, however, been tested 

 by the authors, and found to work satisfactorily. Re- 

 gard is also had to the cost of the operation, as is 

 right in dealing with problems into which financial 

 considerations enter to a large extent. We note that 

 the authors direct attention to the failure sometimes 

 following on fumig-ation with prussic acid ; the proper 

 conditions to ensure success still remain to be dis- 

 covered. 



All who are interested in fruit cultivation will find 

 this book useful. 



Die Fauna Siiduiest-Australiens. Ergehnisse der Ham- 

 burger siidutest-auslralischen Forschungsreise, 1905. 

 Edited by Prof. Dr. W. Michaelsen and Dr. R. 

 Hartmeyer. Vol. ii., sections 1-4. (Jena : Gustav 

 Fischer, 1907-8.) Price 12 marks. 

 A FURTHER instalment of reports on the fauna of 

 south-western .Xustralia, from materials collected by 

 the expedition dispatched from the Hamburg 

 Museum in 1905, has been issued, and contains four 



