Abstract: An incinerator and method for burning both sorted and unsorted rubbish and refuse cleanly and efficiently. Rubbish is inserted in a non-clogging hopper where it is preheated and preliminarily combusted as it moves downwardly to a primary combustion chamber where air is added. A moving grate beneath the primary combustion chamber draws ashes and uncombusted materials downwardly away from that chamber. Gases of combustion are further combusted as they are drawn by the natural draft in the incinerator through a secondary combustion chamber and gas circulating and flyash collecting chamber before exiting through an exhaust. The natural draft through the incinerator is controlled by a series of movable baffles and doors.