34 BULLETIN 313, U. S, DEPARTMENT OF AGRICULTTJEE. 



and shall be securely bedded in broken stone, gravel, or firm earth. In pre- 

 paring the trenches for the curbs great care shall be exercised to see that the 

 material upon which the curb is to be set is well compacted, firm, and hard. 



Stone curbing shall be quarried from hard, tough, homogeneous stone. The 

 individual blocks shall have the cross section shown on the plans and shall 

 be not less than four (4) feet in length. Each block shall be free from seams 

 and all other imperfections and shall be neatly dressed and finished on all 

 exposed faces. 



APPENDIX B. 



Method for Inspecting and Testing Paving Brick/ 



The quality and acceptability of paving brick, in the absence of other special 

 tests mutually agreed upon in advance by the seller on the one side and the 

 buyer on the other side, shall be determined by the following procedure, viz : 



(1) The rattler test, for the purpose of determining whether the material as 

 a whole possesses to a sufficient degree, strength, toughness, and hardness ; 



(2) Visual inspection, for the purpose of determining whether the physical 

 properties of the material as to dimensions, accuracy and uniformity of shape 

 and color are in general satisfactory, and for the purpose of culling out from 

 the shipment individually imperfect or unsatisfactory brick. 



The acceptance of paving brick as satisfactorily meeting one of these tests 

 shall not be construed as in any way waiving the other. 



SECTION 1.— THE RATTLER TEST. 



THE SELECTION OF SAMPLES FOB TEST. 



Item 1. Place of sampling. — In general where a shipment of brick involving a 

 quantity of less than 100,000 is under consideration, the sampling may be done 

 either at the brick factory prior to shipment, or on cars at their destination, or 

 on the street when delivered ready for use. When the quantity under consider- 

 ation exceeds 100,000, the sampling shall be done at the factory prior to ship- 

 ment. Brick accepted as the result of tests prior to shipment shall not be 

 liable to subsequent rejection as a whole, but are subject to such culling as is 

 provided for under Section II (Visual Inspection). 



Item 2. Method of selecting samples. — In general the buyer shall select his 

 own samples from the material which the seller promises to furnish. The 

 seller shall have the right to be present during the selection of a sample. 

 The sampler shall endeavor, to the best of his judgment, to select brick repre- 

 senting the average of the lot. No samples shall include brick which would 

 be rejected by visual inspection as provided in Section II, except that where 

 controversy arises, whole tests may be selected to determine the admissibility 

 of certain types or portions of the lot having a characteristic appearance in 

 common. In cases where prolonged controversy occurs between buyer and 

 seller, and samples selected by each party fail to show reasonable concurrence, 

 then both parties shall unite in the selection of a disinterested person to select 

 the samples, and both parties shall be bound by the results of samples thus 

 selected. 



Item 3. Number of samples per lot. — In general one sample of 10 brick 

 shall be tested for every 10,000 brick contained in the lot under consideration, 



1 Recommended by subcommittee on paving brick of the American Society for Testing 

 Materials. 



