Today’s invention is a false chimney for wood-burning stoves, which allows large bits of timber to be burned -ie without having to chop them into pieces small enough to insert via the front door.
Door A in the false chimney is opened and a large piece of wood inserted. Door A is closed and the door B opened, allowing the wood to drop into the flames.
When B can be slid into the closed position again, A can be reopened and the cycle repeated.