ELASTIC CONSTANTS OF ROCKS- 
Those given for the Lily Lake granite may be considered as representing this 
rock also. Two square prisms of the rock were prepared and on these five 
sets of measurements of vertical compression and two of lateral expansion 
were made. These are given in the accompanying table, and the curves 
Granite, Peterhead, Scotland. 
No 
b 
b 
6 
a 
a 
b 
a 
Size 
1.006 X 1 
.998 X 1.056 
1.000 
.998 
Area .... 
1.006 
1.006 
1.006 
1.052 
1.052 
E 
8,020,000 
8,280,000 
8,375,000 
8,400,000 
8,400,000 
<r 
.204 
.212 
.215 
.214 
.213 
D 
4,520,000 
4,790,000 
4,860,000 
4,900,000 
4,890,000 
C 
3,330,000 
3,415,000 
3,450,000 
3,400,000 
3,400,000 
.... 
i 
Longitudinal compression (multiply readings by 4 for millionths). 
Lateral extension 
(millionths). 
Load (in 
Side. 
Side. 
Side. 
Side. 
Side. 
pounds). 
U. 
U. 
P. 
P. 
P. 
I, OCX). . 


O 
O 
O 

O 
2,OOO. . 
40 
40 
40 
40 
25 
25 
3,000 . . 
85 
80 
85 
80 
50 
49 
4,OOO. . 
125 
120 
125 
1 2O 
75 
74 
5,000. . 
165 
1 60 
1 60 
1 60 
100 
TOI 
6,000. . 
200 
195 
195 
200 
125 
125 
7,000. . 
240 
230 
225 
2 3 
150 
149 
8,000. . 
270 
260 
260 
270 
178 
*75 
9,000. . 
310 
300 
2 9 6 
3 IO 
309 
203 
200 
8,000. . 
270 
1 80 
170 
7,000. . 
245 
.... 
.... 
155 
150 
6,000. . 
205 
.... 
.... 
' .... 
130 
125 
5,000. . 
170 
.... 
.... 
.... 
105 
100 
4,000. . 
135 
.... 
.... 
78 
75 
3,000. . 
95 
.... 
.... 
.... 
54 
49 
2,000 . . 
50 
.... 
.... 
26 
20 
I.OOO. . 
5 
4 
-4 
5 
4 
-5 
2 
9000 
JOOO 
($5000 

Vl 
30OO 
O 40 80 /ZO 160 2OO 240 280 320 
5 TRAIN 
FIG. 13. Peterhead granite. Stress-strain curves. 
