REVIEWS 375 
Practical Field Geology. By J.H. FARRELL. New York: McGraw- 
El BeolksCo., 1902, Pp, 273--xi; figs. 66; tables 4. $2./50. 
The title of this handbook is in a sense misleading. Instead of 
being an exposition of approved methods with practical pointers and 
helpful short cuts for the use of the general geologist in the field, the word 
practical is here construed as synonymous with mining, and the book 
is avowedly limited to a treatment of the field methods employed by 
mining geologists, engineers, and prospectors. Within the field of mining 
its scope is further limited by the omission of coal and iron from con- 
sideration. And in value coal and iron are the greatest of our mining 
products. 
But within its own chosen field the book can be recommended as 
a useful guide. In the first five chapters the methods of topographic 
mapping and some of the simpler phases and problems of geologic map- 
ping are well described and presented so as to be available for use by 
those who have not had the advantages of elaborate training along 
geological lines. Then come very readable and instructive chapters 
on the interpretation of geologic data, general suggestions for geologic 
work, geological measurements, application of descriptive geometry 
to mining problems, application of geological theory, rock classification, 
geological prospecting, and prospecting by drilling. These discussions 
should be of value to those entering the field of economic geology without 
specialized training in that line. 
Following the main part of the book is a guide to the “sight recogni- 
tion”’ of 120 common or important minerals, by A. J. Moses. 
1 Be 
The Coal Fields of King County. By GEORGE WATKINS EVANS. 
Bull. No. 3, Washington Geol. Surv. Pp. 247; figs. 59; 
pls. 23. Olympia, 1912. 
Washington is the only state on the Pacific coast which produces 
coal in any quantity and most of this comes from the region between 
Puget Sound and the main range of the Cascades, principally from King 
and Pierce counties. The coal beds of these two counties belong to 
the Puget formation whose age has been determined as Eocene. In 
character this coal ranges from lignitic bituminous in the less disturbed 
western part of King County to a bituminous coal in the eastern portion 
where crustal movements and igneous activity have been more severe. 
It is a coal that is suited to a great many purposes, though it is not the 
