PHYSICAL PROPERTIES OF ROAD-BUILDING ROCK. 23 



2. A sample of rock for laboratory tests shall consist of stones which will pass through a 

 3-inch but not through a H-inch ring — excepting one piece, which should measure 

 approximately 4 by 6 inches on one face and be about 3 inches thick. The whole 

 sample shall weigh not less than 25 pounds. It is desired that samples of rock be 

 shipped in strong burlap bags. 



3. A sample of gravel shall weigh not less than 25 pounds. Such samples must be 

 shipped in boxes or bags sufficiently tight to prevent the finer material from sifting 

 out. In selecting samples of gravel great care should be exercised in order to obtain 

 material that is an average of the run of pit. 



4. Samples of sand, clay, or marl must weigh at least 10 pounds and should be 

 shipped in strong cloth bags or tight boxes. 



5. A sample of cement should weigh at least 10 pounds and be shipped in a strong, 

 tight cloth bag. 



6. A blank form and addressed tag envelope will be supplied by the Office for each 

 sample. The blank form must be filled out and placed in the tag envelope, which 

 must be securely fastened to the bag and used as the address for the sample. It is 

 essential that the blank forms be filled out with the utmost care, as they are filed 

 as records of the samples. A form, properly filled out, must be attached to each sample. 



7 . The Office desires to keep a record of the actual wear on roads built of the materials 

 tested. If the material which this sample represents has been or is about to be used 

 on roads, this Office desires to be informed of the addresses of those in charge of the 

 construction and maintenance of such roads. 



8. Samples may be shipped, freight, express, or parcel post, and must be fully 

 prepaid. 



9. The Office makes no charge for tests. 



Logan Waller Page, Director. 



Form 5. 



United States Department of Agriculture, 



Office of Public Roads and Rural Engineering, 



Washington, D. C. 



The sample of road material described below is a . 



(Stone, sand, gravel, etc.) 



From the property of 



Located at , , 



(Town.) (County.) (State.) 



Submitted by 



At request of 



Date of shipment Via Wt lbs. 



Approximate quantity of material available 



Individual identification mark 



It is desired that this material be tested to determine its suitability for use as 

 follows: 



Note. — In order to have the proper tests made, it is essential that the above state- 

 ment be as complete as possible. 



Has material been used on roads? If so, where, in what type, and with what 

 results? 



Do not write below this line. 



LABORATORY RECORD. 



Date received Serial No 



Condition of sample 



Receipt acknowledged 



