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 engineering optical fibres for guided lightwave transmission, optical switches, laser amplifiers and lenses, hosts for solid-state lasers and optical window materials for gas lasers, and infrared (IR) heat seeking devices for missile guidance systems and IR night vision. Now a multibillion-dollar a year industry, ceramic engineering and research has established itself as an important field of science. Applications continue to expand as researchers develop new kinds of ceramics to serve different purposes. Glass-ceramic materials share many properties with both glasses and ceramics. Glass-ceramics have an amorphous phase and one or more crystalline phases and are produced by a so-called "controlled crystallization",