VELOCITY IN GRANITE AND LIMESTONE IIl 
the density of a large number of samples taken from the rock in the 
vicinity of the location used. The average value so obtained is 2.65 
ge i a ew oe 
as a il 

Fic. 3.—Time-distance graph, Tishomingo granite. 
grams per cubic centimeter. Using this value, together with the ob- 
served velocities, the elastic constants may be calculated. The values 
thus obtained are shown in Table I. 
633 
