10 



Add measure. This may be either a simple glass cylin- 

 der graduated to deliver IV. 5 cubic centimeters, or one of 

 the more complicated devices shown in figures 4, 5, and 6. 

 A convenient little device is the small glass dipper (fig. 7) 

 by which the proper quantity of acid may be dipped out 

 of a larger container and poured into the test bottle. 



The centrifugal machine. This is commonly called the 

 Babcock -tester, and various types are on the market, rang- 



17.5 

 c.c 



FIG. 4. Simple 

 acid graduate. 



FIG. 5. Burette 

 for measuring 

 the acid. 



FIG. 6. A combined bottle 

 acid measure. 



ing from the small, two-bottle hand tester to the large 

 steam turbine or electric tester, accommodating 24 or 

 more bottles. (See figs. 8, 9, 10, and 11.) They all con- 

 sist mainly of a horizontal revolving disk or wheel pro- 

 vided with swinging sockets to hold the bottles. At rest 

 these sockets allow the bottles to stand upright, but when 

 in motion, the centrifugal force causes the sockets to 

 swing outward, bringing the bottles to a horizontal posi- 

 tion, with the necks toward the center. Where steam 



