A rocket fire mock up. 3 or 4 bricks long x 1 wide. Then stack another row on their sides. The bridge the stack leaving an opening at one end for the flue, and another opening at the other for the wood feed (smaller that the flu gap). Place flu and stack bricks to hold. Light her up. More info: http://en.wikipedia.org/wiki/Rocket_stove_mass_heater
This series of 1 minute videos were uploaded from an Android phone.