Masonry oven India, tandoors are traditional clay ovens, although these days modern electrically fired tandoors are available. The open-topped tandoor is a transitional design between the earth oven and the Roman-plan masonry oven. In the precolumbian Americas, similar ovens were often made of clay or adobe and are now referred to by the Spanish term "horno" (meaning "oven"). Horns are also traditional in the American Southwest. The traditional direct-fired masonry design is often called a "Roman" or "black" oven and dates in Western culture to at least the Roman Republic. It is known as a black oven because the fire generates soot
Masonry oven become increasingly popular among people interested in simpler, less environmentally destructive materials and methods. Wood-fired ovens make popular starter projects, which has generated a large number of "cob oven" projects, many of them documented on the web. However, early masonry ovens going all the way back to ancient Egypt were typically made of native clay, often tempered (to minimize cracking) with gravel, sand, and/or straw. Smaller ovens were built over forms made of sand, or a rough, basket-like shell made of sticks. After the form was covered, the sand was shoveled out, or the sticks burnt. Clome ovens were a