390 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1902. [bull. 213. 
being used for saggers, while the ball clay is shipped to the same 
potteries, being listed there as Tennessee ball clay No. 3. 
It seems probable that Mandle's pits show the contact between the 
stoneware clay series and the Lignitic clays, and that the lower beds 
in Currier's pits may also belong in the Lignitic series. The geologic 
question is in this case of great practical importance, as the Lignitic 
clays are mostly as satisfactory for use as ball clays, and are there- 
fore of considerably greater value than the stoneware clays. 
BRICK CLAYS AND MANUFACTURE. 
The brick clays and brick industry of the region were only examined 
incidentally, and the brief notes taken at several points are here 
inserted, not as being in any sense a complete discussion of the indus- 
try, but as calling attention to some of its interesting features. 
JACKSON, MADISON COUNTY, TENN. 
Four brickyards are in operation in the vicinity of Jackson. All of 
them were visited. 
Charles Owen's yard is located three-quarters of a mile east of the 
court-house, on the Claybrook road. Both common and tire brick 
are manufactured — the former being a surficial deposit near the yard 
1 foot to 5 feet thick; the latter from stoneware clay, obtained from 
pits near those of the Jackson Pottery Company. 
The clay goes from the pits to an iron tempering wheel (C. W. Ray- 
mond's pattern), which is a vertical wheel revolving in a pit on a hori- 
zontal axle, and so arranged that its distance from the center of the 
pit is automatically changed gradually and regularly. It is run by 
two horses; the pit holds sufficient clay to make 8,000 bricks, which 
requires two to two and a half hours' grinding. Three of these wheel 
pits are in the yard, only one being in use at present. The bricks are 
hand molded on a molding table, as a stiff mud, three bricks to a 
mold. Two molding gangs were at work, each consisting of four 
men — 1 bringing mud in wheelbarrow, 1 molding, 1 sanding molds, 
and 1 putting the bricks on racks. Each gang turns out 6,000 
bricks a day. The bricks are dried on pallets in racks and require 
about two days to dry thoroughly. Two kilns are in use holding 
300,000 and 400,000 bricks. The time required is one month to fill a 
kiln, two weeks to burn, two weeks to cool, one month to draw. 
W. M. Payne's yard is located near the Union station (Mobile and 
Ohio Railroad and Illinois Central Railroad). Clay is obtained near 
yard and is about 2 feet in thickness. The bricks are made in an 
"Iron Quaker" brick machine (Wellington Machine Company, Well- 
ington, Ohio). This machine requires nine persons to operate it — 2 
men feed machine from soaking pit, 1 strikes and dumps molds, 1 
sands molds, 1 (boy) washes molds, 1 (boy) puis bricks on slats, and 
3 carry slats to racks. The output of the machine is 16,000 bricks 
