THE MILLING OF RICE. 



ing the grain. The mortars, enlarged to a capacity of 4 to 6 bushels 

 each, were lined with iron, and the pestles, covered with the same 

 metal, weighed 350 to 400 pounds each. All machinery in these mills 

 was operated by power secured from small wood-burning steam 

 engines. The pestles were raised and dropped into the mortars by 

 means of a huge horizontal revolving drum, fitted with spokes which, 

 as the drum revolved, passed 

 into and under slots in the 

 pestles, raising them up, 

 passing, out, and dropping 

 them suddenly with a heavy 

 thud into the mass of rice 

 in the mortars. Machine- 

 driven screens and fans were 

 adopted, and the capacity of 

 a mill employing six or eight 

 mortars was over TOO bushels 

 of rough rice per day. Mills 

 of this type, which were lo- 

 cated at various points along 

 the South Atlantic coast, 

 were the first to attempt a 

 separation of the clean rice 

 into grades according to size. 

 This was done by the use of 

 flat metal screens. 



Very largely increased 

 production in southwestern 

 Louisiana and a demand for 

 a more highly polished 

 product resulted in further 

 mechanical developments in 

 the mills of that region. The 

 rice was first screened to re- 

 move foreign matter, such as 

 straw, weed seeds, and mud 

 lumps. It then passed to a 

 pair of hulling stones, a new 

 machine introduced to perform a part of the work formerly done by 

 the mortar and pestle. The rice fell through an opening in the 

 upper stone, and the revolution of this stone, or " runner," over the 

 " bed stone," which was stationary, caused the grains to incline in a 

 semiupright position between the two stones. The " runner," which 

 revolved over the " bed stones " at a distance above it equal to about 

 two-thirds the length of the rice grain, cracked or split the hull, 



Fig. 3. 



Wooden mortar and pestle used in milling 

 rice by hand. 



