26 BULLETIN 347, TJ. S. DEPARTMENT OF AGRICULTURE. 



Form 20. 



United States Department op Agriculture, 



Office op Public Roads and Rural Engineering, 

 Washington, D. C. 



Report on sample No of road material from 



Made at the request of 



Material 



DETERMINATIONS . 



Specific gravity 



Weight per cubic foot pounds. 



Water absorbed per cubic foot pounds. 



Per cent of wear 



French coefficient of wear 



Hardness 



Toughness 



Cementing value 



Remarks 



Respectfully, 



, Assistant Director. 



APPENDIX B. 



EQUIPMENT OF A ROAD-MATERIAL TESTING LABORATORY. 



A complete list of all apparatus necessary to carry on the work of 

 rock testing follows: 



1 Deval abrasion machine having four cylinders. 



1 impact machine for toughness test. 



1 Dorry machine for hardness test. 



1 impact machine for cementing- value test. 



1 cementing- value briquette-forming machine. 



2 ball mills. 



1 diamond core drill, with suitable drill press. 



1 diamond saw. 



1 grinding lap. 



5 pounds No. 120 carborundum. 



1 small jaw crusher. 



1 scale, capacity 5 kilograms and sensitive to 0.5 gram. 



1 scale, capacity 100 grams and sensitive to 0.1 gram. 



1 balance, capacity 100 grams and sensitive to 0.01 gram. 



1 large drying oven. 



1 small drying oven, with temperature-regulating device. 



1 10-inch desiccator, with calcium chloride. 



1 millimeter scale. 



1 dozen pint jars with metal screw caps. 



1 dozen 3-quart enameled iron pans. 



1 100 c. c. graduate. 



1 100 c. c. beaker. 



1 15-inch standard sieve, with 30 meshes per linear inch. 



1 15-inch standard sieve, with 40 meshes per linear inch. 



1 16-inch sieve, reinforced with square openings one-sixteenth of an inch in size. 



