; 
} 
; 
DECEMBER 25, 1913 | 
NATURE 
475 
advising as to water supply or in carrying out 
works for storage and distribution for domestic 
use or for power purposes. The subjects dealt 
with are the storage and flow of underground 
water in porous soils, and the chemical properties 
of this water, but nothing is said as to how this 
underground water can be made serviceable. 
The chapters into which the book is divided 
relate to:—the source and flow of underground 
water; springs and wells; the chemical, bacterio- 
logical, and microscopical examination of under- 
ground water, together with rules and tables 
relating to water, and a bibliography of books 
bearing on the subjects dealt with. 
The author does not attach much importance to 
the quality of water so far as what is generally 
termed “hardness” is concerned, due to the pres- 
ence of lime, on the ground that the quantity 
contained in the water is so small “that it would 
be necessary to drink gallons of such water at 
a time in order to get enough to have any effect 
upon the system.’’ Whatever may be the case in 
America, the country where the author’s experi- 
ence has been obtained, here it is generally recog- 
nised that water containing lime is very injurious 
to any constitutions subject to complaints such as 
gout or rheumatism. Such water when boiled 
leaves a solid deposit on the bottom of the vessel 
in which it is contained. The effect on domestic 
boilers is very deleterious, and necessitates fre- 
quent scaling to remove the encrustation that 
takes place on the surface in contact with the 
water. The encrustation also of boilers used for 
producing steam for power purposes is a very 
serious objection to the use of hard water when 
it can be avoided. 
Outlines of Mineralogy for Geological Students. 
By Prof. G. A. J. Cole. Pp. viii+ 330. 
(London: Longmans, Green and Co., 1913.) 
Price 5s. net. 
As its name implies, this book is “primarily 
intended for those who are interested in geology, 
and find themselves in need of an introduction to 
the classificatory details of the larger works of 
reference.” Within the limits of 330 pages of 
fairly large type Prof. Cole has produced a text- 
book which, so far as it goes, is trustworthy, 
interestingly expressed, and based upon the now 
firmly consolidated modern ideas of crystal struc- 
ture and symmetry. It has the further recom- 
mendation that it indicates, by footnote references, 
those larger works or original memoirs from 
which further detailed information may be ob- 
tained as regards both theoretical elaborations 
and experimental processes and measurements. 
Moreover, the greater number of these references 
are to works of very recent date, and it is obvious 
that the author has followed the rapid recent 
developments of the crystallographical part of his 
subject with care and keenness. Hence this 
book will form a safe and inspiring guide to 
students embarking on the study of mineralogy 
for the purpose of eventually utilising their know- 
ledge in the field; and although such an object | 
NO. 2304, VOL. 92] 
is not specifically indicated by the author, the 
use of the book can scarcely fail to produce the 
good effect of interesting the. would-be mining 
engineer in the pure science of the subject, and 
possibly of inspiring some original work. 
As regards the half of. the book devoted to 
descriptive mineralogy, a point of special excel- 
lence is the manner in which the phenomena of 
isomorphism and of the periodicity and family 
resemblance in the relations of the chemical 
elements are maintained prominently in view 
throughout. Also the especially able treatment of 
the silicates, so important to the geologist, which 
one would naturally expect from Prof. Cole, is a 
commendable feature of the book. While the 
letterpress is thus of general excellence so far as 
its very limited outlook is concerned, it is to be 
regretted that such illustrations as are new (many 
of the figures being older ones borrowed from 
H. Bauerman’s “Systematic Mineralogy ” issued 
by the same publishers) could not have been of a 
higher character; while perhaps adequate for 
their purpose, they are by no means worthy of so 
well written a book. 
The Elements of Descriptive Astronomy. By 
E. O. Tancock. Pp. 110+xv plates. (Oxford: 
Clarendon Press, 1913.) Price 2s. 6d. net. 
Tuis little book may profitably be placed in the 
hands of boys beginning to take an intelligent 
interest in the heavens. Facts are given mostly 
with accuracy, and stated clearly in simple 
phrasing. There are many half-tone reproductions 
of interesting celestial photographs, and the text 
is helped by numerous instructive line diagrams. 
We may mention No. 13, which excellently ex- 
plains the different noonday altitudes of the sun 
at summer and winter solstices. Efforts are made 
throughout to lead the reader to observe and 
think. <A feature of the book consists in a small 
collection of quotations of an astronomial character 
for the reader to explain. There are some 
blemishes which may perhaps be remedied in 
another edition. Thus the bulk of Saturn is 
incorrectly “deduced,” and its aplatissement is 
much greater than that of Jupiter; also, eight 
significant figures are misleading when employed 
in expressing the distance from the earth to the 
nearest fixed star; and Praesepe might be 
mentioned as suitable for observation with a small 
telescope. Fre BG, 
A National System of Education. By J. H. 
Whitehouse, M.P. Pp. 92. (Cambridge Uni- 
versity Press, 1913.) Price 2s. 6d. net. 
Tuts book is welcome as an indication that our 
legislators are becoming not only more interested 
in national education, but also better informed as 
to English educational needs and shortcomings. 
These brief chapters on all grades of education, 
and on many problems which demand an early 
solution, will serve admirably to instruct ordinary 
citizens as to the duty of the State towards 
education. 
