Charcol fire in the bottom heats wood in a container that keeps air away from the wood. Combustable gases are driven from the wood and the engine burns them.
After all the gases are driven from the wood, it becomes charcol. Then the charcol is moved to the bottom of the device and fresh wood added.
It's not quite that simple, but close.
They were used in Japan, China and Germany for civilian tranportation when they started running out of oil during WWII. Mother Earth News ran a series on conveting engines to wood about 20 some years ago. IIRC, their Chevy pickup got about 1 mile per pound of wood.
The car in front of the woodburner is a 1960s or 70s car, so the woodburner in the picture is someone's resurection or reproduction of a WWII woodburner.
[ October 31, 2004, 11:47 PM: Message edited by: XS650 ]