TESTS OF ROAD MATERIAL I09 



contains the specific density of the stones; column 2, the coefficients of 

 abrasion (determined in the manner previously described) ; the next 

 column gives the number of blows required to stress the 1 in. briquettes 

 to their elastic limits ; column 4 gives the same data for the first testing 

 of the 30 gram (463^briquettes prepared for the recementation test, 

 and the next column gives the number of blows that the recemented 

 briquettes will stand before reaching their elastic limits." 



Through the courtesy of the commission six specimens of typical New 

 York rocks were subjected to the abrasion test with results which are 

 noted in the following table ; which also gives the results of some tests of 

 Massachusetts rocks. 



