164 
NATURE 
Brunoniacez, members of the sympetalous series 
Campanulate. The former is a small but im- 
portant Australian family with about 300 species; 
the latter is a monotypic group, restricted to a 
single species, Brunonia australis, a small peren- 
nial herb of somewhat daisy-like habit, widely 
distributed in Australia. It is interesting to note 
that the wealth of Australian material preserved 
in the great herbaria at the British Museum and 
Kew have supplied a large proportion of the 
material on which Dr. Krause’s monographs are 
based. A. B. R. 
OUR BOOKSHELF. 
Le Monde Polaire. By Otto Nordenskjéld. 
Traduit du Suédois par G. Parmentier and 
M. Zimmermann. Préface du Dr. J. Charcot. 
Pp. xi+324+xx plates. (Paris: Librairie 
Armand Colin, 1913.) Price, 5 francs. 
Here is a handbook to the Polar regions, 
dealing, not with the exploration (of such there 
are plenty), but with the physical conditions of 
the regions, for which there was a vacant place. 
It is well for readers outside Scandinavia that it 
has been translated from the original Swedish into 
French: it might well be so into English. In a 
sense it treats the two polar regions as one, for 
it is comparative throughout, and for that reason 
the chapters are not arranged in a topographical 
sequence. Thus we have: successive chapters 
devoted to Greenland, Iceland, and Spitsbergen; 
the next chapter deals with the Antarctic lands. 
The writer ranges widely enough to include among 
“sub-antarctic ” lands Patagonia and Tierra del 
Fuego, the Falkland and other islands, and New 
Zealand, so far as that Dominion can be con- 
sidered to lie under such conditions; correspond- 
ingly we find chapters on Arctic America (including 
Labrador), on Siberia, and on_ north-western 
Europe. Numerous photographs and _ sketch- 
maps accompany the text, and the French trans- 
lation, which is prefaced by an introduction by 
Dr. J. Charcot, appears to have been excellently 
carried out by MM. G. Parmentier and M. 
Zimmermann. Dr. Nordenskidld’s chapters deal 
with the relief of land, ice conditions and effects, 
plant and animal distribution, climatic conditions 
and human life, and, where appropriate, with 
economic products. 
Coast Erosion and _ Protection. By EouRs 
Matthews. Pp. xiv+147+33 plates. (London: 
C. Griffin and Co., Ltd., 1913.) Price ros. 6d. 
net. 
Tue author of this book writes with a practical 
knowledge of the subject with which he deals. 
He holds the position of Borough Engineer of 
Bridlington, and has constructed sea_ walls, 
promenades, and sea defence works of considerable 
magnitude, which are good examples of what such 
work should be. 
The book follows much the same lines as that 
NO. 2293, VOL. 92] 
[OcToBER 9, 1913 
on the Destruction, Littoral Drift, and Protection 
of the Sea Coast, published by Messrs. Longman 
and Co. in 1902, but it does not treat the question 
of Littoral Drift with the same detail. As that 
book is now out of print, and the author of the 
present book has had the advantage of the large 
body of evidence laid before the Royal Commission 
on Coast Erosion, this work will be a valuable 
aid to engineers called upon to take charge of 
sea defence works. 
The text is very fully illustrated with numerous 
plates showing the effect of waves on sea walls 
and cliffs in course of erosion, and illustrations of 
sea walls, groynes, and other sea defence works. 
As these latter are clearly,drawn, and have the 
dimensions of the several parts marked on, they 
cannot fail to be of great practical use. 
The book is divided into twelve chapters, the 
‘subjects dealt with being: wave action; erosion 
and accretion of the shore; types and designs of 
sea walls; groynes; reinforced concrete; and the 
action of sea water on cement and concrete. 
In his account of the erosion of the Yorkshire 
coast, the author repeats the old fallacy of the 
material eroded from those cliffs being carried 
southward by the tides and being deposited on the 
Lincolnshire shore, and also as being carried up 
the Humber. This subject was fully dealt with 
in a paper on the source of warp in the Humber, 
read before the Geological Section of the Glasgow 
meeting of the British Association in 1go1, in 
which it was shown that it is practically impos- 
sible for this eroded material to be carried so far 
southward; and samples of water taken on several 
occasions of the water entering the Humber on 
the flood tide give no indication of alluvial matter 
being carried into tkat river. 
I Fenomeni Magnetici Nelle Varie Teorie Elettro- 
Magnetiche. Note Storico-Critiche. By Silvio 
Magrini. Pp. 165. (Bologna: Nicola Zani- 
chelli, 1912.) 
TuE scope of this interesting little volume, by 
an Italian author, is novel to English readers; 
at least, the present writer cannot recollect any 
other book devoted entirely to the history of the 
theory of magnetism. Oersted’s fundamental 
discovery that an electric current gives rise to a 
magnetic field in surrounding space was impor- 
tant, not only as the starting point of electro- 
magnetism, but also because, in the hands of 
Ampere, it became the basis of a theory designed _ 
to explain the physical nature of magnetism. 
Beginning at this point, the author passes in 
review the work of Poisson; Faraday’s conception 
of lines of force, with its necessary recognition of 
the part played by the medium; the successful 
development of this idea in mathematical form by 
Maxwell; the theories of Weber and Ewing; the 
experimental work of Curie on diamagnetic and 
feebly magnetic substances; and finally, the 
modern electronic theory of magnetism as extended 
by Langevin, Weiss, Gans, and others. The 
various stages in the historical development: are 
