By beginning with a small amount The reverberatory furnace commonly used for cupelling goes by the name of the English cupelling furnace.
It is oblong, and has a Cupelling.
The latest cupelling furnaces have the general form of a reverberatory copper-smelting furnace.
The same is done with the kettle one-third filled with liquid lead, and so on until the first kettle contains market lead, the last cupelling lead.
The intervening kettles contain leads with silver contents ranging from above market to below cupelling lead.