U. S. DEPARTMENT OF AGRICULTURE, 



BUREAU OF CHEMISTRY- -BULLETIN NO. 79. 



H. W. WILEY, Chief of Bureau. 



THE TESTING OF ROAD MATERIALS, 



INCLUDING THE METHODS USED AND THE RESULTS OBTAINED 

 IN THE ROAD MATERIAL LABORATORY 



IN COLLABORATION WITH THE OFFICE OF PUBLIC-ROAD 

 INQUIRIES. 



BY 



LOGMAN WALLEPt 



Chief, Road Material Laboratory, 



WITH THE COOPERATION OF 



S. CUSHMAlSr, 



Chemist, Road Material Laboratory. 



WASHINGTON: 



GOVERNMENT PRINTING OFFICE. 

 1903. 



