CLAY MANUFACTURES. CLG 
eles of the mass, such as pieces of shale, can frequently be seen separate — 
and distinct from the body clay. ‘The color also of combined oxide of 
iron and silica is dark, running from blue to black, while the color of 
uncombined oxide of iron is red; the color of the Akron pipe is red, 
showing that the impurities are not in a state of combination. But 
though the pipe is not vitrified, it is probably better than if it were, for 
the excess of the iron in the clay would tend to make it brittle if it were 
in real combination. In other words, vitrification would possibly be 
not only an undesirable but a dangerous quality in a sewer-pipe. The 
pipe manufactured by Messrs. Sperry and Rattle at Tallmage, shows 
more nearly a truly vitrified fracture than any seen in the district. 
Judicious experimentation with powdered feldspar, salt, potash solution, 
or any fluxing agent, would very soon establish the practicability, and 
test the advantage of making the pipe vitrify throughout. The Akron 
pipe probably have as wide a distribution as any similar manufactured 
product in Ohio; they go in all directions and in all quantities. The | 
four works in Akron have a yearly capacity of 5,000 car loads. The 
largest works, the Akron Sewer-Pipe Company, have 3 presses, 12 kilns, 
and employ one hundred men. They make pipe by both steam and water- 
power. ‘This factory also claims the distinction of being the largest in 
the country ; it requires a close comparisen to decide between this and 
the Calumet works. The position of Ohio in the sewer-pipe business has 
been mentioned. There are no records available which show the exact 
condition, as the census returns make no mention of it, but Ohio’s annual 
product is probably about $3,000,000 in list price, which is subjected to 
a variable discount. The number of works of considerable size and 
prominence is seventeen. The nearest competitor among the other States 
is New York, which has probably about half the development that we 
have. The States rank in production: Ohio, NewYork, Missouri, New 
Jersey, Illinois, Pennsylvania and Indiana. 
ORNAMENTAL CLAY WORKING. 
The only artistic applications to which clay is put in Ohio are the 
manufacture of encaustic tiling, ornamental pottery and terra cotta. 
Encaustic TILING. 
This beautiful ware is manufactured in only three places in the 
United States at present, among which the works at Zanesville were 
