SCIENCE IN THE INDUSTRIAL WORLD 



garments. It is also reassuring to know that "green- 

 backs" are made from new rags. 



After the rags leave the shredding room they are sent 

 to the "cutters," where they are still further cut and 

 chopped to pieces. Here also the search for buttons and 

 other foreign bodies is continued, large magnets being 

 used sometimes for extracting metal buttons and other 

 bits of iron or steel that may have escaped detection in 

 the other sorting processes. The rags then pass on to a 

 machine called a "devil," or "whipper," which is a 

 hollow cone with spikes projecting within, where they 

 are dashed about, and still more dust and dirt extracted, 

 passing on finally to the "duster" for the final cleaning. 

 This duster is a whirling conical sieve, with air blasts 

 and screens, which remove the last vestiges of dirt and 

 dust particles. 



Obviously all the foregoing manipulations of the rags 

 are simply cleaning processes, and really have nothing 

 to do with paper-making proper. But with the next 

 step the introduction of the rags into the "digesters" 

 begins the real process of turning cloth fibers into 

 paper. The machines in which this process begins 

 are huge revolving boilers, frequently eight or ten feet 

 in diameter and twenty feet high, with a capacity for 

 five thousand tons of rags. These digesters contain a 

 solution of lime and soda, heated with live steam, and 

 here the rags are boiled under forty or fifty pounds' 

 steam-pressure from twelve to fourteen hours. 



By this time the fibers are loosened, as well as the 

 dirt and colors, the contents of the boiler becoming a 

 dark mushy-looking mass, that gives little promise of 



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