106 



GEOLOGY OF OHIO. 



Albany slip clay, average sample from three or four lots of the- 

 Orton. 

 Albany slip clay. Langenbeck. 

 Rowley slip clay. Orton. 

 Brimfield slip clay, Summit county. Orton. 

 Kaolite slip clay. 

 Springfield slip clay, from Sharonville, Hamilton county. Za»- 



1. 



clay. 



2. 



3. 



4. 



5. 



6. 

 genbeck. 



7. Bronhar clay, Zanesville. Langenbeck. 



Nos. 6 and 7 are not in use as slip clays, as far as is known, but were- 

 tested with a view to determine their fitness. 



The Springfield slip clay was found to be an easily fusible clay, 

 which gives a greenish yellow glass, very similar to that produced by the 

 Rowley slip. 



The No. 7 Bronhar clay is used in making a fusible body for tiling,, 

 and is not used as a glaze at all. It requires too much heat to melt it. 



An examination of these clays for their oxygen ratio reveals the- 

 following tabulated facts : 



TABLE lla. 



order : 



6:3: 5:1 and 2: 4, and from the reports gathered among the potters,, 

 these figures are borne out in practice. 



The general character of the natural glazing clays thus is seen to be 

 as follows ; excessively fine grained sandy clays of about the following 

 average composition, 



Clay base _ 3100 



Sand 39 00 



• Fluxes 21.00 



Volatile (water and carbonic acid) 9_00> 



100.0ft 



