TKSTIXi: OK IMMTTLK MATKKI A I.S. 



CONCRETE, STONE, BRICK, AND OTHK1! 

 BRITTLE MATERIALS. 



177- With regard to the testing of these, there is little 

 to be added to what has already been said in describing the 

 tests of cement. The test applied to all these substances 

 is almost invariably the compressive test. Fairly large 

 specimens should be employed, in order to obtain, reliable 

 and uniform results, and, consequently, a large testing 

 machine is required. 



The specimens should be bedded, as in the case of 

 cement, with plaster of paris set in place with the com- 

 pression plates resting upon it. 



The following are some examples of the crushing 

 strength of stones, &c. : 



TABLE OF THE CRUSHING STRENGTH OF 

 VARIOUS STONES, &c. 



