10 BULLETIN 691, U. S. DEPARTMENT OF AGRICULTURE. 



Stone to fill the surface voids when thoroughly rolled. A seal 

 coat of the hot asphalt should then be applied at the rate of 0.4 to 

 0.6 gallon per square yard and covered with a sufficient amount 

 of stone chips to just absorb the excess bitumen. Roads of this 

 character may be maintained with oil surface treatments using 

 the materials and methods given under specifications OC-2 or 

 OH-1. The latter is usually to be preferred. Such maintenance 

 treatments should be applied wlieuever the wear comes directly 

 upon the wearing course rock. 



