284 Reviews—Mineral Industry of the British Empire 
Mesopotamia is shown to be barren of minerals with the exception 
of petroleum. Coal is marked in several places, but an examination 
of the specimens from several of these localities indicates very 
strongly that the substance is an oil residue allied to “‘ manjak ”. 
In Armenia a great variety of minerals occur, but inaccessibility 
would be a serious factor from a commercial point of view. 
Chapter viii, part ii, the Persian-Mesopotamian Oilfields. This 
chapter will be read with great interest by oil technologists. As the 
oil is found for the most part in the gypsiferous series, the discussion 
of its age and origin is of great value. 
The Geology of M esopotanmia and ws Borderlands is concisely 
written, well illustrated with maps and sections, and provided with 
an excellent bibliography. In view of the prominence of 
Mesopotamia and Persia in the public eye, this publication is of great 
practical value. 
A. H Noste. 
THe Mryerat Inpustry or THE British Empire AND ForREIGN 
Countries. Imperial Mineral Resources Bureau Digests : 
Antimony, pp. 34, 1s. net ; Cobalt, pp. 22, 9d. net ; Aluminium 
and Bauxite, pp. 35, 9d. net; Zinc, pp. 112, 3s. 6d. net. 
Stationery Office, 1921. 
HE general plan of this valuable series has been already described 
in a review of the first ten parts in the GrotogicaL MAGAZINE 
for February of the present year. The four further publications 
listed above are drawn up on similar lines, the chief difference being 
in the much larger amount of space allotted to zinc, this, of course, 
being properly commensurate with its greater technical and industrial 
importance. Any such publications at the present time naturally 
form somewhat depressing reading, owing to the stagnation 
prevailing in almost all the mineral and metallurgical industries. 
Besides their value as a record of present resources and a forecast 
of future possibilities, they will always be most useful as a suminary 
compiled from reliable sources of the general trend of the mineral 
industries during the war period. The extensive bibliographies in 
each section will be greatly appreciated by all workers on economic 
mineralogy, 
THe RaptoLartan CHERTS OF THE Franciscan Group. By KE. F. 
Davis. Univ. Calif. Publ. Bull. Dept. Geol., vol. xi, No. 3, 
1918. pp. 235-432, 16 text-figs., 14 plates. 
HIS monograph on the Franciscan Cherts naturally divides 
itself into three parts: a descriptive and comparative study of 
the cherts of the Franciscan and the allied Monterey Group; a 
comparison with similar cherts in other regions, and finally a critical 
discussion of possible modes of origin. 
There are two horizons of Franciscan chert, one 530 feet thick 
