TESTS ON CEMENT 



219 



bottom and racks for holding the briquets. The briquets 

 remain in the molds while in the damp closet, but at the 

 expiration of 24 hr. they are removed, marked, and placed in 

 clean water near 70 F. until broken. 



Testing Machines. There are many styles of testing 

 machines on the market. In Fig. 5 is shown what is called 

 a shot machine, made by the Fairbanks Company. It is 



FIG. 5 



constructed on the cast-iron frame a, and is operated as fol- 

 lows: The cup / is hung on the end of the beam d, the poise r 

 placed at the zero mark, and the beam balanced by turning 

 the weight /. The hopper b is then filled with fine shot, and 

 the briquet to be tested is placed in the clips h. The hand- 

 wheel p is now tightened sufficiently to cause the graduated 

 beam d to rise to the stop k, and the automatic valve j 



