REVIEWS 531 
graph is scattered through several volumes, disconnected, and there- 
fore less known and less valuable either to the state or to the general 
public. Nevertheless, the state geologist is to be congratulated on his 
selection of men to do this work and on the results obtained in so short 
atime, for it is unquestionably one of the very best reports made in 
this country upon building stones. J. C. BRANNER. 
The Ancient Volcanoes of Great Britain. By SiR ARCHIBALD 
Gekiz~ee. ok. Ss: Macmillan & Co, London and New 
York, 1807. 
This work, as Sir Archibald Geike states in the introduction, is the out- 
growth of his presidential addresses before the Geological Society of Lon- 
don in which he sketched the volcanic action in ancient times in Great 
Britain, whose record is left in the igneous rocks of several epochs from 
pre-Cambrian to Tertiary. No other part of the earth, so far as now 
known, presents within a comparatively small area such evidences of 
oft repeated volcanic action through so great a period of time. Com- 
mencing in pre-Cambrian times with three definitely localized volca- 
noes, the series is found to have extended through the Cambrian, Silur- 
ian, Devonian, Carboniferous, Permian and Tertiary times. The impor- 
tance of the evidence furnished by so extensive a series of periods of 
volcanic activity as to the cause of volcanic action, and the source of 
the materials erupted must be apparent. 
Its bearing on the question as to whether volcanic phenomena dif- 
fered materially in the earlier periods of geological history from those 
of recent date, is also most valuable. And it is to be noted that the 
conclusion reached is that they arealike. The presentation of the facts 
known about these ancient volcanoes involves a description of rocks 
that were formed in various situations in the volcanoes ; upon their sur- 
face, within their mass or within rocks beneath or about them; and 
which were subjected during the ages to processes that have modified 
their internal character and sometimes their external form. In order 
that these descriptions may be understood by the general reader the 
first chapters of the work are devoted to a consideration of general 
principles and methods of investigation. The nature and causes of vol- 
canic action, and the phenomena connected with modern volcanoes are 
briefly noted. Considerable space is given to the characteristics of 
