JULY 9, 1897.] 
back to the Archean we find that even then 
the world was an old world. Nor are there any 
Visible signs that the world was then any nearer 
the beginning than it is to-day. Geology has 
thus far found nothing to tell us about the begin- 
ning of mundane things, and our notions of a 
primordial state of the world must come 
wholly from outside the domain of geology. 
With the close of the paleeozoic came a long 
age of quiescence in voleanic action. No traces 
of it have been discovered in any part of the 
Mesozoic of Britain, and only trifling ones in 
the Mesozoic of all Europe. But though the 
fact is a wide one, it is not world-wide. The 
eruptive masses of our own Appalachians, New 
England and Nova Scotia are Jura-Trias, and 
the vast fields of the Deccan in India are as- 
signed to the Cretaceous. That they should have 
slumbered so long in Europe is remarkable, 
but still more so is the fact that their fires 
should have been awakened again with full 
energy in the Cenozoic and often in the same 
old places. 
The description of the Tertiary eruptions of 
Britain is the theme of the greater part of the 
second volume. It is of especial interest to 
American geologists whose labors haye been 
most largely in the far West, where the main 
eruptive masses are distributed all the way from 
early Eocene down to a time which is surely 
post-Glacial. The chapters on these rocks are 
a veritable mine of information. Remarkable 
indeed are the two chapters on the Tertiary 
dykes not only on account of the extraordinary 
development of these features in the island 
of Great Britain, but equally so on account of 
the thorough manner in which they have been 
worked up in the field and in the laboratory. 
Of course, it represents the labor of many in- 
vestigators for several generations, but among 
them we know that our author is preeminent. 
He draws an interesting inference from them. 
While accepting the physicist’s view of the 
general solidity of the earth as a whole, he 
concludes that during the Tertiary volcanic 
period not less than 40,000 square miles of 
Britain were underlaid by one or more reser- 
voirs of liquid lava. ‘This state of affairs he 
puts into relation with a discussion as a pure 
mechanical problem by Hopkins, in 1835, where 
SCIENCE. 
67 
just such conditions were assumed. The in- 
ferred result was the formation of fissures sim- 
ilar in form and grouping to those which field 
observation discloses. 
The chapters on basaltic plateaus constitute 
the most conspicuous subject connected with 
the Tertiary eruptions. Assuredly the grandest 
results of volcanic action the world over are the 
plateau eruptions. Great piles like Shasta and 
/Atna, however imposing, are after all secondary 
in importance. The plateau eruptions of Great 
Britain, their extension into the far North to 
the Faroe Islands, and their possible connection 
with those of Iceland, area grand theme and 
the descriptions of them are worthy of the 
subject. In the author’s mind these plateau 
eruptions often take the form of the so-called 
fissure type as distinguished from the central- 
ized vent, and the dykes as described in preced- 
ing chapters are regarded as the relies of fis- 
sures supplying the lavas of plateaus which 
have been swept away by secular erosion. In 
view of the great importance attached to the 
massive eruptions from fissures he introduces 
an interesting sketch of the lava fields of Ice- 
land, which are believed to furnish the most 
impressive examples of recent occurrence. 
American geologists will take a lively interest 
in the chapters which follow, describing the in- 
trusive Tertiary rocks, especially the olivin-gab- 
bros and the eruptive granites. We have them 
in this country and they have awakened warm 
discussions as to their real nature. Their true 
eruptive character is now beyond dispute, and 
their occurrence in Tertiary time is an impor- 
tant consideration in establishing the practical 
identity of volcanic action in the most ancient 
and most recent ages. The British examples 
are certainly admirable ones and are described 
with the author’s usual precision and clearness. 
It seems like trifling with a serious subject to 
merely notice in this fragmentary way a few 
points in this great work, which abounds in an 
unspeakable wealth of instructive and interest- 
ing material, all wrought out and delineated 
with a master hand. The arrangement is ad- 
mirable. Everything is in logical order, and 
whatever precedes is a preparation for that 
which follows. The broad plan of the work is 
historic progression, and as we complete the 
