Tn? FRANK D. ADAMS 
at a depth of 15 miles, a slight diminution in the diameter of the 
holes is observed, even if this pressure is only maintained for a 
period of 70 seconds. This movement, however, is not increased 
even if the rock be maintained at this pressure and temperature 
for an additional period of 70 hours. In the last experiment, 
however, when the heat rose for a time to 513°C. the transverse 
hole, as noted, became completely closed, which may have been 
connected with a partial disassociation of the Ca CO, molecule 
caused by the high temperature. 
GRANITE, WESTERLY, RHODE ISLAND, U.S.A. 
A knowledge of the behavior of this rock under deep seated 
conditions is of especial importance, because it is a typical repre- 
sentative of the great class of plutonic igneous rocks which make up 
so large a portion of the earth’s crust. 
This well-known rock is a fresh, fine-grained, massive, pale 
pink granite, composed essentially of biotite, microcline, orthoclase, 
and quartz. A detailed description of its microscopic characters 
as well as the results of a study of its elastic constants are give 
in Publication No. 46 of the Carnegie Institute of Washington." 
The crushing strength of the granite was determined on 2-inch 
sawed cubes, all the precautions referred to in the case of the Solen- 
hofen limestone being employed to secure accuracy. ‘The results 
were as follows: 
Ist cube= 28,340 lbs. per square inch 
2d cube= 26,410 cc cc (73 « 
NVeET Age — 27,3715) ae ct ance a 
It will thus be observed that the rock is not quite so strong as the 
Solenhofen limestone under the ordinary conditions of a test for 
crushing strength. 
Columns of the granite were prepared, bored, and placed in 
their enclosing tubes of steel in the manner already described. As 
in the case of the Solenhofen limestone, a series of experiments 
t Adams and Coker, An Investigation into the Elastic Constants of Rocks, etc., 
Carnegie Institute of Washington, Washington, 1906. 
