32 
NATURE 
[Marcu II, 1915 

Mr.  Wallis’s “Geographical Exercise 
consist of blank maps (sometimes with 
(3) 
Books ” 
contour lines), and on the page facing each map 
a series of questions or directions as to filling it 
up and writing notes or exercises on the results 
obtained and the conditions revealed. Both maps 
and letterpress appear to be very judiciously 
chosen or compiled, and in the hands of a pupil 
of moderate capacity in draughtsmanship the 
finished product should possess a permanent 
value. 
(4) Messrs. Bacon’s ‘‘Sixpenny Contour Atlas ” 
is very good, considering its price. It contains 
thirty-two coloured maps, showing the elevation 
of the land according to a recognised method, 
and dealing with the world and its 
divisions, in addition to which there are a few 
various 
maps of a special area, varying according to the 
pupil’s requirements—e.g., the edition 
notice is that for south-east England, and con- 
tains special maps of that district, while editions 
for south Scotland, south Wales, and others are 
promised. 
(5) The same firm’s publication, “ The Map and 
its Story,” does not maintain the standard of 
the work previously noticed, so far as concerns its 
coloured maps illustrating climate, 
etc. Some of the printing (e.g 
«fey 
vegetation, 
of the natural 
resources shown in red lettering) is bad, and some 
of the distribution weak. But the 
distinctive feature of the work, the letterpress 
accompanying the maps, explains them very 
clearly, and ought to fulfil the purpose of guiding 
students as to what they should look for and 
find, not only on these, but on other maps. 
colouring 
OUR BOOKSHELF. 
Huxley Memorial Lectures to the University of 
Birmingham. ith an Introduction by Sir 
Oliver Lodge. Ppa LoA. (Birmingham : 
Cornish Brothers, Ltd., 1914.) Price 5s. net. 

OF the nine memorial lectures which have been 
delivered, the present volume contains only five. 
That by Prof. Joly on pleochroic halos does not 
even mention Huxley’s name. Sir Oliver Lodge 
leads off with Huxley’s own defence against the 
charge of materialism. “There is a third thing 
in the universe which . I cannot see to be 
matter or force, or any conceivable modification 
of either.” This was consciousness. Sir 
Michael Foster found in Huxley the “conviction 
that what began as a search into things physical 
has become a search into things spiritual.” Prof. 
Poulton points out that Huxley “never com- 
mitted himself to a full belief in natural selection, 
and even contemplated the possibility of its 
NO. 2367, VOL. 95] 
under | 


ultimate disappearance.’’ We come, in the re- 
markable paper by Prof. Percy Gardner, to the 
pith of the matter, ‘‘in regard to which words 
from Birmingham are greatly valued, the study 
of the subconscious side of man.” 
Prof. Bergson’s lecture on life and conscious- 
ness traverses a field antipodal to that of 
Huxley. Consciousness is ‘‘the mind.” It “and 
matter are antagonistic forces.” It is at once a 
“creative force,’ a “vital impulse,” and a 
‘spiritual force.” Life is ‘nothing but conscious- 
ness using matter for its purposes.” It “cuts it 
up in order to bring about a greater precision.” 
“The evolution of life . suggests to us the 
image of a current of consciousness which flows 
down into matter as into a tunnel.” The final 
conclusion is ‘‘that with man consciousness has 
finally left the tunnel” to “pursue its path beyond 
this earthly life.” 
| Dew-Ponds—History, Observation, and Experi- 
ment. By E. A. Martin. Pp. 208. (London: 
T. Werner Laurie, Ltd., n.d.) Price 6s. net. 
A pIFFICULT problem has been attacked by Mr. 
E. A. Martin in this book. He defines a dew-pond 
as ‘one situated on the higher grounds, generally 
on the chalk downs of the south of England, which 
retains by some means or other a supply of water 
throughout all but the most prolonged droughts. 
| whilst those ponds situated on the lower lands 
have consistently dried up.”” With the aid of con- 
tinuous observation, and a grant from the Royal 
Society for experimental purposes, he has been 
able to throw much light on these curious ponds. 
He shows that ‘‘dew-pond” is a misnomer, for 
dew is quite insufficient to make up for loss by 
evaporation; and he inclines to the use of the 
term ‘‘mist-pond”’’ as better explaining their 
origin. However, ‘“dew-pond” is in common use, 
and when farmers speak of dew they include the 
condensation of mist and cloud also. 
The author suggests that the small crystals of 
sodium chloride, found in sea air, have acted “as 
nuclei of condensation when the night-mists form 
on the downs, and as the mists blow up in the 
early morning from the sea they pass across the 
pond-depressions and are deposited in quantities 
there.” Certainly it is to the morning mists 
drifting in from the sea that the replenishment of 
these ponds is mainly due. We would direct par- 
ticular attention to some of the observations, in 
which are given actual measurements of the 
amount thus deposited. It is noticeable also what 
a large part is played by rushes or other vegeta- 
tion in increasing the deposition. However, 
aspect, slope of ground, and other things all play 
their part, and great care is needed in the selection 
of a site. 
We recommend this book to the notice of en- 
gineers and others who have to do with hilly 
regions where rain is deficient, but where heavy 
mists are common, as, for instance, the Pacific 
slopes of the Andes. 
