APPENDIX B. 337 



square, with rounded corners), weighing i pound. It is to be allowed to drop on the 

 mixture from a height of about i inch. When the ramming has been completed, 

 the surplus cement shall be struck off and the final layer smoothed with a trowel held 

 almost horizontal and drawn back with sufficient pressure to make its edge follow the 

 surface of the mold. 



14. The above are to be considered the minimum requirements. Unless a cement 

 has been recently used on work under this office, bidders will deliver a sample barrel 

 for test before the opening of bids. If this sample shows higher tests than those given 

 above, the average of tests made on subsequent shipments must come up to those 

 found with the sample. 



15. A cement may be rejected in case it fails to meet any of the above requirements. 

 An agent of the contractor may be present at the making of the tests, or, in case of the 

 failure of any of them, they may be repeated in his presence. If the contractor so 

 desires, the Engineer Officer in charge may, if he deems it to the interest of the United 

 States, have any or all of the tests made or repeated at some recognized standard testing 

 laboratory in the manner herein specified. All expenses of such tests shall be paid 

 by the contractor, and all such tests shall be made on samples furnished by the Engineer 

 Officer from cement actually delivered to him. 



SPECIFICATIONS FOR NATURAL CEMENT. 



1. The cement shall be a freshly packed Natural or Rosendale, dry, and free from 

 lumps. By Natural cement is meant one made by calcining natural rock at a heat 

 below incipient fusion, and grinding the product to powder. 



2. The cement shall be put up in strong, sound barrels, well lined with paper so 

 as to be reasonably protected against moisture, or in stout cloth or canvas sacks. 

 Each package shall be plainly labeled with the name of the brand and of the manu- 

 facturer. Any package broken or containing damaged cement may be rejected, or 

 accepted as a fractional package, at the option of the United States agent in local charge. 



3. Bidders will state the brand of cement which they propose to furnish. The 

 right is reserved to reject a tender for any brand which has not given satisfaction in 

 use under climatic or other conditions of exposure of at least equal severity to those 

 of the work proposed. 



4. Tenders will be received only from manufacturers or their authorized agents. 

 (The following paragraph will be substituted for paragraphs 3 and 4 above when 



cement is to be furnished and placed by the contractor : 



No cement will be allowed to be used except established brands of high-grade 

 natural cement which have been in successful use under similar climatic conditions to 

 those of the proposed work.) 



5. The average net weight per barrel shall not be less than 300 pounds. (West of 



