It's another giveaway from Mother Earth News! This time you could win the Liberator Rocket Heater that uses gravity to feed both fuel pellets and waste wood such as sticks, blocks, staves, branches, dead-fall and scraps.
Epic Greenhouse Rocket Mass Heater - The insulation board has be laid in on the floor of the thermal-mass trench, inches of gravel added, and now the pipe has been assembled with a single screw holding each section of pipe together.
Rocket mass heater - Commercially sold by Dragon heaters - captures all the heat in the "bells" and will continue heating 13 hours after the fire is out. For those with limited space with no room for a huge mass like a cob bench.