DALLAS COUNTY. 75 
feet. From 6 to 8 feet of gray joint clay is exposed. The lignite 
bed of the upper bank was not observed here, but the upper part of 
the bluff is covered with debris. The clay is fine grained, with some 
grit, and clings strongly to the tongue. This clay has been used 
more extensively than any other in the county and has uniformly 
been pronounced good by potters. 
Bird clay. — The Bird clay bed outcrops on a hillside near one of 
the small streams flowing from the south into Cox Creek, in the 
NW. I NE. i sec. 6, T. 7 S., R. 15 W. The same clay outcrops farther 
west, around the head of Cox Creek, and farther east along the 
breaks of the hills skirting the north edge of Gum Bottom. The por- 
tion of the bed that was worked stands 390 feet above sea level, but 
clay of apparently the same quality outcrops in places in the drain 
all the way up to the elevation of 440 feet. This would indicate 
that the bed is about 50 feet thick. At the pit about 15 feet is 
exposed. This clay is said to have the disadvantage of being diffi- 
cult to dry without cracking. This fault could be remedied by a 
judicious admixture of other clays. When freshly exposed the clay 
is light bluish in color and very plastic. It is very fine grained and 
contains but little grit. 
Analysis indicates that this is a good clay, the silica and alumina 
being in good proportion and the percentages of the fluxes very 
moderate. 
Welch clay.— This bed is located in the SE. { SW. J sec. 6, T. 8 S., 
R. 15 W. The bed stands 355 feet above sea level, making it corre- 
spond very closely in elevation with the Butler clay, described above. 
The bed has been dug into for 7 or 8 feet, and the quality of the clay 
improved and its color became lighter as greater depth was reached. 
The clay occurs in angular lumps, is light bluish gray in color, and 
is very fine grained, with little grit. Mr. Welch reports that the 
joint spaces are filled with a crystalline substance somewhat resem- 
bling common salt, and that particles of this substance become 
embedded in the ware and make blisters when burning. Samples of 
ware made from this clay are hard and close bodied. It burns to a 
gray slate color when perfectly done, the softer pieces varying from 
yellow to brown. 
Mr. Welch reports that he is unable to use the common slip glaze on 
this clay, for the reason that the heat necessary to melt the glaze 
melts the ware also, and that he is compelled to glaze with common 
salt, which, however, is very satisfactory. The ware made from 
this clay shows to some extent a feature mentioned in connection 
with the Bird clay — a tendency to crack and warp in the dry house. 
Sullenbarger clay. — The Sullenbarger clay bed is in the NE. ', sec. 
20, T. 8 S., R. 15 W. The clay was used by Lafayette Glass in 
1870. Nothing can be seen of the clay used, as the pit has long 
