Masonry oven these primitive-looking ovens were still being produced in Barnstaple potteries as late as 1890". A cloche or cooking bell is like an upside-down, fired ceramic bowl with a handle on top. It is heated in the fire along with a flat rock or open spot on the hearth. The prepared dough is placed on the hot rock or hearth floor, and then covered with the cloche, and perhaps hot coals or ashes for additional heat. The method goes back to ancient Egypt and Greece, and was probably the first form of masonry oven. It is possible to get some of
Ceramic heat cell power per cubic meter, operating at a moderate temperature of 1200 °C, with output varying from 5% to 100% of this, responding in 5 milliseconds. Emissions are claimed to be well below 10 parts per million even without exhaust gas recirculation. A glow plug is used to start the cell. Ceramic heat cell A ceramic heat cell, also known as Caloric Porous Structure Cell (CPSC), is a ceramic device to burn a fuel without flame, converting the thermal energy to mechanical work. In principle any fuel that can be vapourised and pre-mixed with air can be used. "Ultra vaporized steam"