Lucifer Furnaces supplied several top-loading pot furnaces to a customer for use with glass and ceramic research. The furnaces, which will be used for salt-bath heat treatment, are constructed with multilayered insulating firebrick and mineral-wool insulation for maximum heat storage and low outside skin temperature. The units include a stainless steel pot designed with a flange for sealing against the roof plate, which is constructed of heavy-gauge steel plate to withstand warping and distortion from chamber heat. Heavy-gauge, coil-wound, low-watt-density heating elements in easily removable radiant panels are located on all four side walls of the heating chamber and are divided into several zones to provide uniform heat to 1500°F. Separate thermocouples monitor both chamber and pot medium temperatures.