REVIEWS. 207 


















Though these views are so entirely novel, and even startling, and 
opposed in respect to the origin of granite to the results obtained by the 
Survey among the vast masses of granite in Canada West, it is 
nevertheless a philosophical essay which commands our respect from its 
solidity, and the evident familiarity and experience of the author with his 
subject. Whe ther the principles laid down are true or not in the general 
application for them cla imed, this essay has RSE on opened a new 
to geological investigation 
THE VOLCANOES OF THE HAWAIIAN ISLANDS. *— This work is filled with 
numerous observations, many of great value, made by the author during 
his travels among these islands. The whole group is treated one by one 
in detail. 
rom Mr. Coan, and others resident among the Sandwich Islands, the 
author gathered many interesting facts with regard to the various erup- 
tions of the volcanoes of Hawaii, and the physical geography of other 
members of the group. 
The maps of the Kauai and main 1 groups are E A and the crater of 
Kila 
by 
p 
One fact of pebcrad intent is, that while the ieaiai lines of vol- 
canoes run east and west, the major axis of their oval craters are invari- 
and south, and, by comparison with the craters of eighteen 
other lines of v olcanoes, it is found that they are generally at right angles 
ce the axes of elevation of the different mountain chains to which they 
long. 
Mr. Brigham pines to the mechanical theory of the origin of vol- 
canoes,— ‘the earth’s crust contracts unequally owing to its various 
ition, Structure, and form, causing certain portions to fall below 
ral 
level era rents at the boundaries, and forcing up molten 
matter to the su 
EOLOG 
sistant, Mr. O. H. St. John, has extended over the counties to 
West of the Des Moines River, ae resulted in the discovery of 
two series of the Carboniferous rocks. The upper series of beds lie to 
the south- ing 
and Seventy Ava feet. y coal-bed, twenty inches in thickness, was 
along the aey of the Nodaways through the counties of Adam 
» d Page. The upper series, comprising nearly all the workable 
s in the rigs found to the north-east of the Des Moines ae | 
t miners in the south-western counties may expect to find pro- 


on the Voleanoes of the Ha f their various E T per 
righam, A.M. Memoirs of the ites Society of pss: History. Vo: 
With five plates 
and Second Amina Report Ba Sah ss. By the State Geologist and the —"" an 
on the Geologi cal Survey of the State of Iowa. Svo, 284 pp. Des Moines, 

