Reviews—The Mineral Resources of Great Britain. 85 
reasonable and common-sense attitude adopted in controversial 
questions. Many current subjects are discussed in an impartial 
manner, the arguments on both sides being fairly stated. As an 
example we may perhaps quote the temperate summary given on 
pp. 416-22 of the difficult problem of the classification of the igneous 
rocks, a subject which has of late attracted much attention on bot! 
aides of the Atlantic, and is admittedly as yet far from settled. 
The petrologist, mineralogist, and economic geologist will find in this 
book a mine of information on many little-known points of interest, 
together with voluminous references to original memoirs. By a 
rough computation the index contains nearly 7,000 headings, and 
there are few workers in any branch of geology who will not here find 
some new and valuable information often culled from the most 
recondite sources. 
SpecraL REPORTS ON THE MINERAL RESOURCES OF Great BRITAIN 
Vol. VIL: Mineral Oil, Kimmeridge Oil-shale, Lignites, Jets, 
Cannel Coals, Natural Gas, England and Wales. Second 
edition. pp.iv-+125, with a plate and 7 text-figures. 1920 
Price 5s. net. 
HE second edition of this interesting and useful memoir has been 
enlarged and amplified by an account of the explorations lately 
going on for oil in Great Britain, brought up to the date of going to 
press. We note, however, with regret that this date is as far back 
as June, 1919. A map is given showing the position of the borings 
in the Chesterfield-Mansfield district, and their relation to the 
geological structure, together with a general section of the Car- 
boniferous strata of Derbyshire, and a diagram showing the lie of 
the rocks along a line from Ashover past the Hardstoft boring. 
From this it is clear that the small accumulation of oil there was due 
to a roll in the strata combined with specially favourable local 
conditions. The total production up to October, 1919, was 849 
barrels—a quantity which is of no practical significance as a com: 
mercial proposition, taking into account the cost of a 3,000 feet bore 
A short account is also given of the work undertaken for the 
establishment of a Kimmeridge oil-shale industry in Norfolk, with 
a description of the strata encountered in various borings and shafts. 
Fossils have been recognized belonging to both Lower and Upper 
Kimmeridgian zones, and some horizons are richly fossiliferous. 
An investigation of the cannel and other oil-yielding rocks has 
shown that cannels are of strictly local development, and the best 
seams are nearly exhausted. This does not seem to show any promise 
of being a future source of commercial oil-supply. Oe 
ivi, Jel, 188 
