
































_ = C ._2s 
Marcu 10, 192 3] F 
si 
> 
some matter referring to the loss of power at altitudes 
in aero engines. Two methods have been proposed for 
getting rid of this difficulty, namely, the production of 
an artificial atmosphere by means of a blower in the 
carburettor intake, or using an oversize engine, which 
is kept throttled down at low altitude. In either case, 
the object is to design an engine which can develop 
[constant power up to a certain height. For altitudes 
up to 20,000 feet, the over-dimensioned engine appears 
to be considered the simpler solution. 
4 lazes and Labyrinths: A General Account of Their 
_ History and Developments. By W. H. Matthews. 
| Pp. xviii+254. (London: Longmans, Green and 
Co., 1922.) 18s. net. 
Mr. MATTHEWS, who does not pretend to be a trained 
heologist, tells us that his book originated in a 
question addressed to him by his little son as he played 
on the seashore, “ Father, who made mazes first of 
?” As his bibliography shows, he has studied the 
information summarised in a popular way. He begins 
with the two great labyrinths of antiquity, that at 
Egypt. In describing these, he depends on the safe 
ce of Sir A. Evans and Prof. Flinders Petrie. 
‘The former was based on a tradition of the complex 
¢ buildings forming the royal palace, the latter was 
possibly used for sepulchral purposes. Though, as 
ir James Frazer suggests, the dancing-places associated 
vith these ancient labyrinths may have been used in 
some magical way connected with sun worship, it is 
lifficult to connect them with modern mazes, like those 
at Hampton Court or Hatfield, adjuncts to garden 
anning, and intended for the amusement of visitors. 
Phe best part of the book is the collection from various 
ources of illustrations of various types of mazes. 
any of these have been destroyed in modern times, 
ind this book may serve a useful purpose in directing 
ittention to their interest, and may tend towards the 
preservation of those which survive to our day. 
The Outdoor Boy. Edited by Eric Wood. (The 
Modern Boy’s Library.) Pp. 280. (London: 
_ Cassell and Co., Ltd., n.d.) 5s. net. 
1 ROBABLY no class of the community takes a greater 
‘interest in the education of their sons than the readers 
of Nature. While the most suitable form of educa- 
tion will long remain the subject of debate, few will 
deny the importance of the out-of-doors side, both 
from the point of view of awakening a love for and an 
interest in Nature and preparing for the duties of 
citizenship. 
Ye book before us, one of a series edited by Mr. 
Wood, is divided between scout-craft and Nature- 
a , the idea being to convey to the boy in a clear 
and simple manner many of those things which he 
‘most wishes to know. The scout-craft section appears 
a 
ruida 
tion to many a boy who is unable to join an actual 
‘scout troop. The Nature-craft section consists of an 
excellent chapter on bird study and similar chapters 
packed with information about the insect world. 
Boys upon whom we have tried the test find it alto- 
gether admirable. 
NO. 2784, VOL. 111] 
NATURE 
literature of the subject, and he has collected much’ 
Knossos in Crete, and the second near Lake Moeris in 
to us most admirable and should be a mine of informa-* 
321 

A Text-book of Quantitative Chemical Analysis. By 
Dr. A. C. Cumming and Dr. S. A. Kay. Fourth 
edition. Pp. xv+432. (London: Gurney and 
Jackson; Edinburgh: Oliver and Boyd, 1922.) 
I5s. net. 
THE first edition of this book was published in 1913, 
and the appearance of the fourth edition less than ten 
years later shows that it has been found in practice 
a most useful guide to students. The present volume 
should provide a sound course of quantitative analysis 
for students in universities and technical schools. It 
is very practical, and gives many hints to students 
which will save the time of teachers. The reduction 
method with Devarda’s alloy might have been given 
for the estimation of nitrates, instead of the one with 
reduced iron, which is less satisfactory, In the descrip- 
tion of the Lunge nitrometer no mention is made of 
the important correction for the solubility of nitric 
oxide in the acid. The directions for the preparation 
of cupferron reagent on p. 410 will be found useful, 
as the price charged for this substance is almost 
prohibitive. 
Group Psychology and the Analysis of the Ego. By Dr. 
Sigm. Freud. Authorised translation by James 
Strachey. (The International Psycho-Analytical 
Library, No. 6.) Pp. v+134. (London: G. Allen 
and Unwin, Ltd., 
A coop and clear translation of Freud’s short essay on 
group psychology is given by Mr. Strachey. The work 
begins by a brief examination of the views of earlier 
writers, particularly of Le Bon and M*‘Dougall. 
Freud’s own method of approach to social psychology 
is naturally by way of an analysis of the motives of 
individual behaviour. He treats the group as a collec- 
tion of persons bound together by some form of love 
relationship, and to the formation of the group ascribes 
what to many will appear to be an overweighted im- 
portance to the leader. His discussions of the phe- 
nomena of “ identification,” and of the relations of 
“being in love and hypnosis,” are interesting in them- 
selves ; but his application of the results of his dis- 
cussions to the explanation of social behaviour is not 
convincing. 
1922.) 7S. 6d. net. 
Elementary Organic Chemistry. By W. H. Barrett. 
Pp. 256. (Oxford: Clarendon Press; London: 
Oxford University Press, 1922.) 4s. 6d. net. 
Durinc the last two or three years a number of ele- 
mentary books on organic chemistry have appeared, 
and it may be doubted whether any purpose is served 
by further multiplication of the same material treated 
in the same way. The present volume has no very 
new features, but it gives a very clear and interesting 
account of the fundamental facts and theories of 
organic chemistry suitable for students preparing for 
scholarships at the universities. It also provides a 
course suitable for those beginning the subject in the 
universities, and for medical students. Experiments 
are included. The section on stereochemistry is 
particularly good, and a chapter is devoted to general 
methods of synthesis and analysis. The very moderate 
price of the book and its undoubted merit should make 
it popular. 
