1991.064.338
Print, Photographic
Black and white photographic print mounted on fabric depicting mills at the Champion Spark Plug Co.
Caption reads: Photograph 6
A battery of 6-foot diameter pebble mills used for final grinding of the previously weighed out body mixture. These mills revolve at approximately 17 R.P.M. Each mill carries 5 tons of porcelain balls made of our regular porcelain body. To do proper grinding it is necessary that the balls be within definite size limits. The grinding charge of the body is not only a definite amount but the water used with it to form the creamlike slip is also accurately measured. This gives a definite specific gravity and viscosity and results in uniformly fine grinding and dependability.
