REVIEWS 219 
These old glacial deposits occur on the north as well as on the 
south side of the island and frequently have a considerable thickness. 
At times lavas are interbedded in a way which suggests close proximity 
in time of the volcanic and the glacial forces. At other places there 
appear to be indubitable proofs of a general absence of glacial condi- 
tions at times of great volcanic activity. Doleritic lavas with their 
upper surface scored by the latest moraines, rise several hundred feet 
above old eroded surfaces of earlier glacial drifts. How many there 
are of the latter one cannot yet definitely say. Apparently there are 
more than one. It is noted that all these older moraines are asso- 
ciated with the palagonite tuffs, and there is some reason to think that 
they were made at some period during Miocene-Pliocene time. ‘This, 
the author remarks, is a strange indication, in view of the what is known 
concerning the glacial age on the continent. But further investiga- 
tions are needed to determine the age. The relation of the moraines 
to some fossil-bearing crags on the north coast promises more light on 
this question. 
In the south half of the island the breccia plateau was for the 
greater part built after the moraines were made. ‘The principal relief 
features of the land, as for instance the south lowland, are younger 
than even the uppermost of the palagonite moraine. 
The heavy and extensively distributed ice-scored doleritic lava 
flows, show that there was a long interglacial period, for they overlie 
unconformably older moraines. ‘The fossil-bearing crag at Tjérnes, 
already referred to, may prove to belong to this stage. Heretofore 
this deposit has been regarded as belonging to the Pliocene. 
J. A. UDDEN. 
The Cement Industry. Descriptions of Portland and Natural 
Cement Plants in the United States and Europe, with Notes 
on Materials and Processes in Portland Cement Manufac- 
ture. Reprinted from the Engineering Record, New York. 
THIs interesting series of papers gives a very fair idea of the devel- 
opment of the cement industry at the time of their first publication a 
few years ago. Originally written for the Lnxgineering Record by S. 
B. Newberry, Frederick H. Lewis, and others especially interested in 
cement, as independent articles describing typical cement plants of 
Europe and America, they are now published, together with an appro- 
