Reviews — The Mineral Resources of Great Britain. 231 



in some localities the dips are as high as 60°, though over a 

 considerable area the beds are nearly flat. The coal is of anthracitic 

 character, averaging about 79 per cent of fixed carbon, 10 per cent 

 of volatile matter, and 6 per cent of ash, with a calorific, power of 

 about 13,770 B.T.U. It is of good quality, well suited for 

 industrial uses, although possessing poor coking properties. 

 A highly conservative estimate gives a workable quantity of 

 152,900,000 tons, allowing an abundant margin for all contingencies 

 in working. 



A brief account is also given of the tungsten ores of Huaura, and 

 of a newly discovered region in the neighbourhood of Tarica, as well 

 as of the copper deposits of Magistral. 



R. H. R. 



III. — Special Reports on the Mineral Resources of Great Britain. 

 Vol. VII : Lignites, Jets, Kihmeridge Oil-shale, Mineral Oil, 

 Cannel Coals, Natural Gas. Part I: England and Wales. 

 By A. Strahan. Mem. Geol. Survey, pp. 69, with 1 plate and 

 3 text-figures. 1918. Price 2s. 6d. 



DURING the last four years there has been a vast amount of 

 irresponsible talking and writing about the possibility of the 

 discovery of workable sources of oil and other natural fuels, other 

 than coal, in the British Isles. It is, therefore, highly satisfactory to 

 find that the Geological Survey has collated all known information 

 on the subject, examining the records of past operations so far as 

 available, and in the case of present explorations, carrying out 

 independent investigations on the spot. The scope of the Memoir 

 is sufficiently indicated by its title. The most important sections 

 deal with the lignites of Bovey Tracey, the explorations made in 

 them by Germans and others, and the uses to which they have been 

 put; the distribution of Kimmeridge Oil-shale throughout the 

 country; the principal known occurrences of mineral oil, cannel 

 coal, and natural gas. It may be said at once in general terms that 

 a careful perusal of this volume does not lend any notable amount of 

 support to the highly optimistic views set forth in the daily papers 

 during the last year or two. 



A very full description is given of the well-known lignite and 

 clay deposits of Bovey Tracey, and of the somewhat obscure 

 operations of the German company, which mysteriously vanished 

 two days before the declaration of war. It appears that the 

 products of their industry were not of satisfactory quality, owing to 

 the fact that the lignite consists mostly of highly resinous Sequoia 

 wood, which seems to be unsuitable for the manufacture of paraffin 

 wax and similar materials; the chief product of distillation being 

 an evil-smelling yellow tar, a wholly unsaleable substance. 

 Detailed sections are given of several borings put down in this area ; 

 these show the presence of a large amount of lignite, which is 

 apparently only of poor quality and much mixed with clay. It is 

 also shown that lignite has a wide distribution in Tertiary, 

 Cretaceous, and Jurassic rocks, but nowhere in workable quantities. 

 A brief account is given of the almost extinct Whitby jet industry. 



