THE MILLING OF EICE. 
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 700 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 
Fig. 3.- 
-Wooden mortar and pestle used in milling 
rice by hand. 
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, 
