670 GEOLOGY OF OHIO. 
are Ist, wetting the clay; 2d, grinding; 3d, wedging; 4th, turning; 
Sth, drying; 6th, slipping; 7th, burning; 8th, sorting the product. 
In very many places the clay is put into a bin before using, and 
allowed to stand over night after drenching with water. This precau- 
- tion is well taken, particularly in smaller works where horse-power only 
is used in grinding; in the largest steam works it is not necessary. 
The grinders for stone-ware clays are of several kinds ; the simplest is 
a pug-mill, which is used in only one place visited. The next machine 
has no specific name, but is the one in use in all the country potteries. 
It is a square frame pivoted on an upright beam, which runs through 
the point of crossing of the diagonals, on the projecting ends of which 
are fastened cart-wheels, which work in a circular trough beneath. 
The whole frame revolves by the motion of a large cog-wheel above, 
which receives its power from the horse or engine; the motion is slow, 
but by weighting the corners of the frame, the wheels in their revolu- 
tions manage to cut the clay to pieces quite effectually. Such a machine, 
which can easily be made by any village mechanic, can grind from 
twelve to fifteen hundred pounds at a charge, and will occupy about two 
hours in doing it. This amount of clay will make from 180 to 190 
gallons of ware. The clay, after grinding, is balled into large masses 
and “wet-blanketed” to keep until used. The grinding is done in the 
Akron district in steam mills called tracers, which will be further 
described under the head of the sewer-pipe manufacture. They are very 
efficient for stone-ware clays, grinding about 1,200 pounds to a charge in 
from 60 to 100 minutes. The clay being ground is put through a process 
called wedging ; it is cut off in balls of 50 pounds or more, and cut by a 
wire into two parts; these are struck together in such a way that the 
two pieces unite different faces ; the ball is worked up smooth again and 
is alternately divided and united by cutting halves and striking them 
_ together. | 
This treatment is supposed to eliminate blebs or spaces on the clay 
and any large pieces of foreign matter. When wedged, it is rolled up 
into wads or balls which have a definite weight for each kind of ware, 
and is then ready to be turned. The process of turning is too well 
known to require description. : 
The simplest work is making crocks and fruit jars, and after that 
come jugs, milk-pans, churns, ete. The range in size is from one pint 
to twenty-four gallons, though vessels holding forty gallons have been 
