488 
domes of Louisiana. They show that the most 
recent work has confirmed the hypothesis that 
these salt-domes occur at the intersection of two 
rectangular series of fractures. The Calgary 
field, which created a fever of speculation in 
south-western Canada, is more than once quoted 
as illustrating that the predominance of light oils 
is a discouraging feature as an indication that 
the oils have travelled for some distance. They 
refer to the present investigations to check H6fer’s 
theory that the geothermal gradient rises most 
rapidly in oilfields, but they regard it, even if veri- 
fied, as a not very hopeful method of prospecting. 
The final chapter is on the oil market and future 
supply. All through the book may be recognised 
the tacit assumption that the days of an oilfield 
are short and that a period of declining oil pro- 
duction is not far distant. Then, say the authors, 
will be the day of the oil shales, of which there 
are large quantities, which can then be more 
profitably worked. They remind us, however, that 
there is not likely ever to be an absolute failure 
of oil for purposes for which it is indispensable. 
So soon as oil production begins to decline the 
price will rise, and its employment will be re- 
stricted to the purposes for which oil alone can 
serve. It will no longer be squandered on uses 
for which there are more enduring reserves of 
alternative materials. De WEG. 
OUR BOOKSHELF. 
Wisconsin Geological and Natural History Survey. 
Bulletin No, xxxvi.. The Physical Geography 
of Wisconsin. By Dr. Lawrence Martin. 
Pp. xxii+549. (Madison, Wis.: Published 
by the Stete, 1916.) 
Tue “Educational Series’? to which this work 
belongs is “primarily designed for use by teachers 
and in the schools ”’ (p. 486), and the cloth-bound 
volume of 549 pages, with abundant maps and 
illustrations, is “sent on receipt of 15 cents” 
(74d.) to those who are sufficiently keen to ask 
for it. Wisconsin, like Canada, places no bar to 
the spread of educational information collected by 
the State. 
Dr. Martin is careful to explain — technical 
terms as they arise, but he writes for the advanced 
teacher, who will’ appreciate the details shown 
in his well- selected. maps. The romantic history 
of Indian, French, and American Wisconsin 
is bound up with the geographical position. 
To this day (p. 12) the most valuable articles 
manufactured in the State are “the orcducts 
of the wood-working industry, which come 
from the soil.’ In many ways, even in the 
abundance of lakelets in the north (p. 388), we 
are reminded of Finland, where the soils depend 
also to a large extent on glacial transport. But 
Wisconsin has some 4o in. of annual rainfall, 
distributed under the extremes of a continental 
climate, and the wind-weathering that forms 
pinnacles and rock-tabies in the driftless areas 
does not imply continuous aridity. On the west we 
come across the broad sweep of the Mississippi, 
1 el below Prescott between isolated bluffs, 
2469, VoL. 98] 
NATURE 
[FEBRUARY 22, 1917 
which are in reality the extremities of divides cut 
through by the young and dominant stream. We 
are grateful to the author for the sympathetic 
record on p. 170 of Black Hawk’s heroic stand on 
the Mississippi bluffs in 1832. 
thus the humane, touch can never lie far from the 
geographer. GRENVILLE A. J. COLE. 
The North Staffordshire Field Club. Jubilee 
Volume, 1865-1915. Edited by S. A. H. 
Burne, J. T. Slobbs, and H. V. Thompson. 
(Published by J. and C. Mort, Stafford.) Price 
7s. 6d 
AN immense amount of good and useful scientific 
work has been accomplished during the last fifty 
years in the United Kingdom by local natural 
history and archeological societies. Not only 
have these bodies stimulated local research, but 
by affording means of publication they have been of 
inestimable service to science in placing on record 
accounts. of local discoveries, co-ordinating 
methods of study, and enabling the embryo 
student to try his prentice hand at authorship. 
The North Staffordshire Field Club is a typical 
society of the kind, and having attained its 
jubilee, it has just issued a commemorative volume, 
which consists of a sufficiently full record of the 
work performed by the members during the fifty 
years of its existence, compiled by the president, 
together with an account of the work done in the 
various sections by the respective chairmen. The 
work of the club is organised in sections, and is 
carried on by means of monthly excursions under 
approved leaders during the summer, ‘and the 
reading of papers and debate at evening meetings 
during the winter, and it must be admitted that 
the results of the fifty years’ work are an unquali- 
fied success. It is not permitted to everyone to 
live to see the full fruition of their pioneer work, 
but the fates have been kind enough to Mr. W. D: 
Spanton to permit him to live not only to see 
his offspring successful, but also to act as presi- 
dent on the fiftieth anniversary of the club he was 
instrumental in founding. 
Having now reached maturity, it behoves the 
club to consider itself more seriously and to ex- 
tend its work. For example, the histories of 
Roman and Saxon Staffordshire have still to be 
written. Botany and zoology include much more 
than the mere listing of finds, and the annual 
volumes would be better if shorn of the many 
platitudes which still add to their bulk, but not 
to their usefulness. 
Macmilian’s Graphic Geographies. 
Isles: By B.C." Wralliss Pp. 22. 
and Co., Ltd.) Price od. 
Tue beginner in geography is here provided with 
a combined atlas and text-book. The simply 
worded lessons, in which the human note is pre- 
dominant, are supplemented by four coloured, 
full-page, orographical maps and twenty-four 
further maps in black and white. The exercises 
at the end of the lessons, and the occasional test- 
papers, will supply the teacher with the material 
necessary to secure the active co-operation of the 
pupil throughout the course of instruction. 
The British 
(Macmillan 
The human, and ~ 
eer 
a 
