Abstract: A high temperature furnace and method for thermally decomposing solid combustible fuels into usable products to provide a source of heat to a selected area is disclosed. Solid combustible fuel, such as waste automobile tires, are introduced into a reaction vessel or combustion chamber which is defined by an outer wall. The reaction vessel has an upper portion and a lower portion with a central partition dividing the lower portion into compartments. Each compartment holds a fuel bed having a selected height wherein the sold fuel accumulates as it is being decomposed. Each compartment also has a bottom opening. Air ducts located along the outer wall of the reaction vessel and in the central partition supply pressurized air to the interior of the reaction vessel. An exhaust duct which communicates with the upper portion of the reaction vessel is supplied for venting off combustion or pyrolysis products from the reaction vessel to the selected area.