INTERNAL FRICTION IN ROCKS 



623 



Pounds 

 100.000 



Fig. 7. — True curve obtained by the deformation of a standard column of Carrara 

 marble in steel cylinder with wall 0.25 cm. thick. The area designated by oblique 

 lines represents the work done in effecting the deformation of the marble to a bulge 

 of o. 150 inch. 



