Subclass 30/10: Combustion apparatus with driven means for agitating the burning fuel; Combustion apparatus with driven means for advancing the burning fuel through the combustion chamber with movable, e.g. vibratable, fuel-supporting surfaces; with fuel-supporting surfaces that have movable parts with fuel-supporting surfaces that are specially adapted for advancing the fuel through the combustion zone with fuel-supporting surfaces having fuel advancing elements that are movable, but remain essentially in the same place, e.g. with rollers or reciprocating grate bars