214 ANNUAL REPORT 
50, Sand,—Sand will be sensibly free from loam, clay, or other impurity, 
sharp, angular, and silicious. When used in connection with cement tests 
in the place of standard quartz, it must give results in each case at least 
equal to those obtained by the use of standard quartz. Samples of the sand 
proposed to be furnished shall be submitted with each bid and retained in the 
office of the Department of Public Improvements as a standard for comparison 
during the progress of the work. 
51. Broken Stone, —Broken stone for concrete: All of the stone used in 
the dam must be excavated from the area covered by the site designated by 
the Engineer, selecting and using only such stone as is hard and durable, 
of a quality approved by the Hngineer, and of such character as to break 
in approximately cubical fragments. It will be broken so that no dimensions’ 
shall be greater than one and one-half inches and must be thoroughly screened 
from dust and dirt, and washed if deemed necessary. 
