May 13, 1922] 



NATURE 



607 



great practical and economic importance. It is 

 frequently stated that hydraulics is an empirical science 

 because water differs from the ideal fluid to such an 

 extent that the theoretical hydrodynamical investiga- 

 tions are not of much value to the hydraulic engineer. 

 While this in a measure is true and it is necessary to 

 resort to experiments to determine the exact form of 

 the formulae which express the flow of water along pipes 

 and the co-efficients to be used in them, nevertheless, 

 there are many problems connected with the flow of 

 water in mains which are capable of analytical treat- 

 ment, and the volume under notice has for its principal 

 aim the discussion of these problems. 



In chapter i the general hydraulic principles of 

 flow are discussed and empirical formulae such as 

 those of Chezy and Kutter are quoted, tables of co- 

 efficients to be used with them for clean pipes being 

 given. There is no attempt whatever to give 

 particulars of modern researches, and so far as this 

 chapter is concerned with loss of head by friction, 

 no experimental work done during the last thirty-five 

 years is considered worth mentioning. As regards 

 losses by bends and elbows recent researches have 

 been referred to, but no consideration is given to the 

 very important question of the change in the carrying 

 capacity of a pipe with time. The general principles 

 are, however, clearly discussed, and it may fairly be 

 said that this chapter is written as an introduction 

 to the chapters which follow, in which the problems of 

 the surge chamber and v/ater hammer in pipe lines are 

 \ery fully discussed. 



The two succeeding chapters deal very fully with 

 stresses in pipe lines, with the materials of construction, 

 and with the design of pipes. The last chapter of the 

 volume deals with the flow of oil along pipe lines. The 

 important effect of temperature on the viscosity is 

 emphasised and a curve is given showing how the 

 pressure drop per mile can be obtained when the 

 temperature is changing. 



There are four appendices in which certain special 

 theoretical problems are dealt with. In Appendix i 

 the general theory of pipe line flow is considered 

 from the theory of dimensions. In this connection 

 it is surprising to an English reader to find no reference 

 to Lord Raleigh, or to the work of Stanton and Pannell, 

 or Lees, and throughout the whole book there is very 

 little reference to much important work that has been 

 done in this country. To English readers also such 

 symbols as {pJ2) and {jis), meaning pounds per square 

 foot and cubic feet per second respectively, may 

 appear a little awkward, but the notation used through- 

 out the book is summarised at the commencement. 

 The work should prove of value to serious students of 

 the subject. F. C. L. 



NO. 2741, VOL. 109] 



Recollections of a Geologist. 



Memories of a Long Life. By the Rev. Canon T. G. 

 Bonney. Pp. iv-i-ii2-f-vii. (Cambridge: Metcalfe 

 and Co., Ltd., 1921.) 



A LIMITED edition of this little book has been 

 printed. It is meant primarily for Cambridge 

 readers, but will be perused with affectionate interest 

 by the many other friends of its author. It has also 

 some wider appeal as the unaffected and revealing life- 

 story of a last-century Don. Not many of us can 

 aspire to a retrospect so gratifying in its entirety; 

 and we congratulate the author on his enviable pos- 

 session. 



Beginning in 1837 with the hearing of minute guns 

 on the death of William IV., the " Memories " cover 

 a period of over eighty years (and are happily still con- 

 tinuing). Of the wide scientific achievements of their 

 narrator they tell little, but are vivid with incidents 

 and anecdotes of his boyhood, undergraduate days, 

 and later professional life in Cambridge and London, 

 with recollections of eminent men and abnormal 

 weather. In the parlance of relativity, the events for 

 the most part pertain to a particular system of reference 

 and would scarcely be recognisable as events in another 

 system ; but they combine, within their limits, into a 

 concordant and sharply individualised picture of a 

 career " crowded with culture." They exhibit a life of 

 continuous mental and bodily activity ; terms of strenu- 

 ous duty alternating with pleasant vacation tours in 

 the Alps and elsewhere, usually fruitful in scientific 

 results ; and in their long range they recall the changes, 

 both in material things and in mental outlook, that 

 have become apparent during their course. It is a 

 cheerful picture, in which we may occasionally catch 

 the trace of vigorous old controversies that, like the 

 little whirlwinds of hot weather, have now and again 

 raised temporary commotion within the sphere of their 

 impact without disturbing the broad serenity of the 

 plain. 



There is strong spice in the caustic remarks on the 

 unseemly behaviour and dress of some of the under- 

 graduates of to-day, and in the comments on the 

 motor-car and bicycle, the latter of which " shoots 

 out silently from hidden byeways, the rider never 

 dreaming of using his bell." But the good-nature 

 underlying it all is illuminated by the episode of a 

 happening, years and years ago, when the author, then 

 junior Dean, cleverly detected an undergraduate in a 

 prankish breach of order in Chapel, and brought him 

 before the Seniority with a stem demand on its im- 

 willing members that " if you do not send him down 

 you must appoint some one else to sit there in future, 



