586 
NATURE 
[JuLy 29, 1915 


while the description of genus and species on 
p- 351 gives the authoritative spelling in the name 
Theodoxus lutetianus. 
(7) The numerous new species described in Mr. 
E. A. Smith’s treatise are illustrated in two excel- 
lent plates. Mr. Smith’s mastery of the subject 
almost forbids criticism, but may still excuse 
inquiry in regard to his use of the generic names 
Rissoia and Panope. In the ‘ Discovery”’ 
Gastropoda, 1907, he transferred without explana- 
tion his Rissoa adarensis to Rissoia. Under 
Rissoia adarensis (Smith) he now adds a note: 
“A synonym of Rissoa is Apanthausa, Gistel 
(‘ Naturgesch. Thierreichs,’ 1848, p. x),” without 
explaining what is the relationship of Apanthausa 
to Rissoia. In 1850, Gistel in the ‘‘ Handbuch 
der Naturgeschichte,” p. 554, declares that Rissoa 
must be changed (though he does not say why) 
into his Anatasia, the date of which is given 
by Scudder as 1848. Neither Gistel in 1850 nor 
Scudder later on makes any mertion of Apan- 
thausa. <A further perplexity is caused by Mr. 
Smith’s change of Panopaea zelandica, Quoy and 
Gaimard, into Panope zelandica, without any 
reference to show that Panope, as the name of 
a molluscan genus, antedates its use in 1813 by 
Leach for a genus of Crustacea. Les “ Panopes,”’ 
Lamarck, Ann. du Mus. Paris, vol. x., p. 394, 
1807, is a French term. 
T. R. R. Sressine. 

CHIEFLY MONGIAN GEOMETRY. 
(1) Descriptive Geometry for 
Engineering Science and Architecture. A Care- 
fully Graded Course of Instruction. By Prof. 
H. F. Armstrong. Pp. vi+125. (New York: 
J. Wiley and Sons, Inc.; London: Chapman 
and Hall, Ltd., 1915.) Price 8s. 6d. net. 
(2) Geometry of Building Construction: Second 
Year Course. By F. E. Drury. Pp. xii+226. 
(London: G. Routledge and Sons, Ltd., 1915.) 
Brice as met 
(3) Practical Science and Mathematics. By E. J. 
Edwards and M. J. Tickle. Pp. viii+175. 
(London: G. Routledge and Sons, Ltd., 1915.) 
Price 1s. 6d. net. 
Students in 
(1) HE geometry of Monge, in which three- 
dimensional bodies are represented by 
plan and elevation, is one of the most educative 
branches of mathematics; and yet it is taught 
in this country only as a technical subject for 
engineering and architectural purposes. The 
secondary school is unaware of its existence. 
Hence the pleasure with which we find a Canadian 
writer on the subject reckoning that his book will 
be used in high schools. Let us hope that the good 
NO. 2387, VOL. 95] 


| traditions of Canada will be adopted by England. 
The book covers the usual ground. The problems 
are based on the usual conventional figures. The 
book is beautifully got up, the text and figures 
both being admirable. 
(2) This book is also on Mongian geometry. 
In place, however, of the conventional subjects, it 
treats real problems of building construction 
throughout. It is, in fact, intended as a builder’s 
text-book. Just on that account it forms a suit- 
able book for any student of Mongian geometry. 
The propositions of the subject presented in the 
abstract are too difficuit.for the majority of 
students. The treatment of the propositions as 
inductions from concrete problems makes them 
much easier to grasp and to retain. This distinc- 
tion is realised by the author and forms the basis 
of the book, as indeed it does of the whole series. 
The book is certain to have a wide sphere of 
usefulness. 
(3) This book also belongs to the excellent series 
edited by Mr. Udny Yule. It is concise and clear, 
the style simple and direct. The inductive method 
is wisely followed, a number of particular 
cases being followed by a generalised statement. 
It is a useful book, and avoids confusing the 
mind by excess of abstract reasoning. There is 
a generous use of graphs, and the only fault 
we find is the failure to emphasise the fact that 
the “algebraic law of the relation between 
two quantities’ y=ax+b is only one among 
many possibilities. 


ELECTRICAL ENGINEERING 
TEXT-BOOKS. 
(1) A Treatise on the Theory of Alternating 
Currents. By Dr. A. Russell. Vol i. Second 
Edition. Pp. xiv+534. (Cambridge: At the 
University Press, 1914.) Price 15s. net. 
(2) Electrical Engineering. By Dr. T. C. Baillie. 
Vol. i. Introductory. Pp. vii+236. (Cam- 
bridge: At the University Press, 1915). Price 
5s. net. 
(3) Electrical Instruments in Theory and Practice. 
By W. H. F. Murdoch and U. A. Oschwald. 
Pp. viii+366. (London: Whittaker and Co., 
1g15.) Price 1os. 6d. net. 
(4) Alternating-Current Electricity and its Applica- 
tions to Industry. First Course. By W. H. 
Timbie and Prof. H. H. Higbie. Pp. x+534. 
(New York: J. Wiley and Sons, Inc. ; London: 
Chapman and Hall, Ltd., 1915.) Price 
8s. 6d. net. 
(1) NEW edition of Dr. Russell’s book will 
be welcomed both by physicists and 
electrical engineers, particularly by those who 
