In 1903, Robert Hall and his son, Robert T. Hall, seized the opportunity to purchase a defunct pottery in East Liverpool Ohio. Short on cash but full of optimism, Hall and his father began producing and selling pottery. The young Hall, needed to produce high quality ceramics without the use of lead – because the old kilns fired too hot.

And, so he did. The first step required the formulation of a glaze without lead. In 1911, he had succeeded after years of experimentation. Not quite finished, he developed a “secret formula” for the clay body – a mix of feldspar, flint and fine china clays. The white body and the lead-free glaze fused in slow firing – actually 24 hours. Years later, the production time was vastly reduced with improvements to the tunnel kilns.

The Secret Process remained a secret, no doubt, largely because the danger of lead was not an issue for most consumers. Additionally, the vitrification process for commercial china effectively formed a fused glass-like final product

Notes:

Barbara J. Conroy, Restaurant China : Identification & Value Guide for Restaurant, Airline, Ship & Railroad Dinnerware (Volume 2)

The East Liverpool, Ohio, Pottery District: Identification of Manufacturers and Marks (Historical Archaeology Vol. 16, Nos. 1-2)

Carnegie Public Library: https://www.carnegie.lib.oh.us/hall

Pottery Works at East Liverpool Ohio: https://www.thepotteries.org/potworks_wk/067.htm