28 
AN INVESTIGATION INTO 
WHITE MARBLE, VERMONT, UNITED STATES- 
This is a pure white marble indistinguishable from the Carrara marble 
in a hand specimen. Under the microscope also it resembles this rock very 
closely. The grains show, however, a somewhat greater variation in relative 
size and there is a tendency to a flattening in one direction, giving a 
very faint foliation to the rock. On this account only a single specimen 
was used, since the foliation in question, although barely perceptible, might 
affect the elasticity of rock, and it was therefore considered safer to 
rely upon the Carrara marble in measuring the elastic constants of this 
class of rocks. In the prism of Vermont marble employed, the foliation lay 
in the direction of the longer axis of the prism. It is probable that this folia- 
tion would not be found in all Vermont marbles, but happened to be present 
in the specimen procured for examination. 
A. photomicrograph of a thin section of the rock, in this case taken between 
crossed nicols and magnified 31 diameters, is shown in Plate III. A color- 
process photograph was not prepared, since the rock in such a photograph 
would be identical in appearance with the Carrara marble, of which such a 
photograph has already been given. 
Vermont Marble. 
Size 
1.017 X 1.012 
Area 
1.029 
E 
7,592,000 
or 
.263 
D 
5,341,000 
C 
3,000,000 
Load (in pounds). 
Longitudinal 
compression, 
(multiply 
readings by 4 
for millionths). 
| Lateral 
extension 
(millionths). 
I,OOO .... 

40 
80 
120 
157 
2OO 

30 
64 
IOO 
135 
172 
172 
140 
1 08 
75 
39 
i 
2,OOO 
3,OOO 
4,OOO 
5,OOO 
6,OOO 
7,OOO 
8,000 .... 
9,000 
8,000 
7,000 
6,000 
2OO 
I6 5 
125 
90 
51 
5 
5,000 
4,000 
3,000 
2,000 
1,000 
