384: Tlic American Geohxjiat. Docomber, 1896 
gular forms and sharp serrated peaks. It is evident that at 
one stage of tlie ice-sheet these were nunataks rising above 
the level of the ice, wiiich is now approximately represented 
by the jjosition of the lateral moraines. 
From the above evidence it seems clear that in this part of 
Greenland, at least, the continental ice-cap once extended far 
beyond its present limits. Whether, in its extreme extension, 
it passed beyond the limits of the outer headlands into the 
broad waters of Baffin's ba}', I have not sufficient data to 
judge; nor from the limited area studied during the five weeks 
can any legitimate conclusions be drawn for other portions of 
the coast north or south of theUmanak region. 
REVIEW OF RECENT GEOLOGICAL 
LITERATURE. 
The Elements of Geology: A text-book for Colleges and for tlie General 
Reader. By Joseph Le Conte. Fourth Edition, revised and enlarged, 
with new plates and illustrations. (New York. D. Appleton and Co., 
1896.) The well-known author of this popular work has rendered geol- 
ogy, and especially American geology, a service by revising it and incor- 
porating in this edition some of the results of more recent investigations. 
It is to-day probably the best known of American geological text-books, 
and the improvements impressed on this edition will tend to keep it in 
the lecture rooais and libraries of most American geologists. 
The entire book is divided into three parts, viz: Dynamical Greiilogy, 
Structural Geology, and Historical Geology, in the order named, which 
is natural and logical. Under Dynamical Geology the treatment of vol- 
canoes, geysers and eai'thquakes is full, perhaps unreasonably full, for a 
text-book on geology, although these agents are among the most inter- 
esting and powerful of geological history. There is here, and in the 
discussion of the action of glaciers, a series of "graphic" illustrations, 
some of which, after the clear enunciation of the facts and the princi- 
ples involved, do not add to the clearness of the text, but are, instead, 
even embarrassing. For instance, after the paragraph on p. 47, on 
"Motion of Glaciers. " which is clear, simple and comprehensible, one 
might ask: what is the need of the "Graphic Illustration" of the same 
movement given on page 48, which involves the study of a diagram with 
its lettering and its lining, its ordinates and co-ordinates? To many 
readers it is an unpleasant obstacle, as it gives nothing new, and is 
more time-consuming and difficult of understanding than the simple 
summary statement of the paragraph that precedes it. In general, how- 
ever, the illustrations, though not of first-class execution and quality, 
axe important aids to the text. 
