REVIEWS 587 
rock occurs, and within which the better constructed buildings suffered, even 
when built upon a good subsoil. Outside of this zone the character of the sub- 
soil, foundations, and building materials have but little influence. 
6. Persons living on the earthquake or close to it often hear subterranean 
rumblings resembling that produced by a train passing through a big tunnel... . . 
[7 consists of a description of the subterranean sounds. } 
8. It is noted in my studies of each locality that destruction is caused always 
along certain lines more or less perpendicular to the sea, and consequently to the 
Andes ranges, and that they frequently extend to both of the transverse valleys. 
. . . . When seismic vibrations follow these lines the places along them receive 
vertical shocks and movable objects on the surface move in the direction of the 
vibrations, that is, toward the east. 
In regard to the geologic relations of Chilean earthquakes the author 
further concludes (pp. 57, 58): 
The strata or layers of rock laid down on the bottom of the sea during the 
Secondary and part of the Primary periods are now many thousands of meters 
above sea-level forming the present Andes. These enormous masses of detrital 
rocks began to be raised in the Tertiary period, pushed up largely by the rock 
we have called ‘‘seismic.”” This upward movement is not yet ended, for our coast 
is gradually rising at the rate of about one meter per century. [There follows a 
theory of an ancient submerged continent to the west of the present one.] The 
sinking of this ancient continent of the Pacific gave rise to the present American 
continent, and in order that these gradual and sudden uplifts should be brought 
about on the coast of Chile it is necessary that the bottom of the sea should be 
depressed. [At this place the author inserts the following footnote: ‘Sr. Montes- 
sus de Ballore, professor of seismology, in a lecture at the University of Chile 
announced as a new idea that the earthquake of August 16, 1906, had affected more 
violently the towns in front of the great heights of the Andes and consequently 
adjoining the greatest (ocean) depths. As this gentleman does not mention the 
source of this idea, we call his attention to this point which we had aiready set 
forth.”] These elevations and depressions tend to produce a break or fault. 
In some places these faults appear in the littoral belt, but on the coast of Chile 
they are beneath the water; and for this reason the towns on the coast suffer 
more than those in the interior. 
In Chile it happens that two earthquakes never occur in succession in the same 
place. I believe this is due to the fact that the continent of the Pacific (the sub- 
merged one) requires a greater pressure to lift the American continent. This it 
obtains in time, while the rivers of Chile are bringing down heavy materials 
derived from the Andes. Thus we have here a kind of balance in which one 
of the arms slowly furnishes the other with a weight sufficient to disturb the 
equilibrium. 
J. C. BRANNER 
