Outlines of Geologic History with 
Especial Reference to North America 
Symposium Organized by 
BAILEY WILLIS 
Compilation Edited by 
ROLLIN D. SALISBURY 
(5 teats and all readers of geologic 
literature will welcome the publication, 
in book form, of an important series of 
essays and discussions on the subject of geologic 
correlation under the title, Outlines of Geologic 
History with Especial Reference to North America. 
They embody the present state of knowledge 
and opinion concerning many of the funda- 
mental problems of North American geology, 
and form an admirable supplement to earlier 
treatises and manuals. 
The value of the book is greatly enhanced 
by the fifteen paleogeographic maps by Bailey 
Willis which accompany the papers. 
cloth 
316 pages — 8vo $1.66 postpaid 
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Lectures on the Calculus of 
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By OSKAR BOLZA, Ph.D. 
Of the Department of Mathematics in the 
University of Chicago 
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