480 Reports & Proceedings—British Association. 
enamelling iron ware. Fluorite of optical quality is rare and of 
considerable value. 
This pamphlet gives a résumé of the production of fluorspar in 
the different countries of the world: it is chiefly mined in England 
and in the United States, lesser quantities coming from Canada, 
South Africa, New South Wales, France, Austria, and Germany. 
Jn 1918 the output of fluorspar in the United States was no less 
than 235,551 tons, valued at over a million dollars, while in the same 
year Hngland produced 53,498 tons, chiefly from Derbyshire. 
There are also important deposits in Durham, Cumberland, and 
Northumberland. 
Fretp Mapping ror THE OiL Gronocist.. By C. A. Warner. 
pp. x +145, with 40 figures. New York: Wiley. 1921. 
Price 18s. 6d. net. 
HIS small but expensive book deals with the methods of field 
mapping as applied specially to oil geology; nevertheless. 
much of it is of general application. A useful account is given of 
the different kinds of maps employed as a basis of field work, and 
full descriptions of plane tables and other instruments are set out, 
with instructions for their use. The author rightly lays stress on the 
value of underground contour or subsurface maps, a part of the 
subject usually neglected in English textbooks, although of immense 
importance in mining and oil geology. Nearly half the book is 
occupied by tables of various kinds, partly mathematical, partly 
the geological formations of the oil-bearing regions of the United 
States. 
REPORTS AND PROCEEDINGS. 
British ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE 
Edinburgh Meeting, 1921. 
Titles of papers read in Section C, Geology :— 
Dr. J. 8. Flett, F.R.S.—Presidential Address on Experimental 
Geology. 
Professor T. J. Jehu—The Geology of the Edinburgh District. 
Professor Baron G. J. de Geer.—An Exact Time Correlation 
between the Glaciations of North America and Europe. 
Professor W. H. Lang, F.R.S.—The Flora of the Rhynie Chert 
Bed. 
Professor L. W. Collet.—Alpine Tectonics. 
Mr. H. M. Cadell. — Evidence from recent Bores in the 
Carboniferous Rocks of Scotland. 
Mr. T. M. Finlay.—New Fish Zones in the Old Red Sandstone of 
Shetland. 
Mr. F. Dixey—The Magnesian Group of Igneous Rocks. 
Mr. H. H. Read.—The Contaminated Magmas of Aberdeenshire. 
