fig3 apparatus according to a specific embodiment of the invention will now be described the following specifications are currently preferred where the organic matter being used as raw material is sawdust these specifications are included here for illustrative purposes the optimal temperature to which furnace 6 should heat retort 4 is approximately 600 u00b0 c the interior of furnace 6 is preferably coated with a suitable lining 50 such as a 1500 u00b0 c tolerant refractory lining 50 should be at least 3 inches thick thermal insulation 52 at least one inch thick should be provided between lining 50 and outer wall 54 of furnace 6 outer wall 54 may be fabricated of steel retort 4 ideally has an internal diameter of about 14 inches diameter 56 of flight 26 is ideally about 12 inches enlarged path 36 created by the offset of auger 22 in retort 4 has a maximum height 58 of about 2 inches pitch 60 of flight 26 is ideally about 9 inches plug formation tends to occur with substantially lower pitch diameters while substantially higher pitch diameters do not provide sufficient time for organic material in retort 4 to convert to charcoal auger 22 ideally has two gap sections 28 28 u2032 and two corresponding projections 30 30 u2032 gap sections 28 28 u2032 should be about 4 inches in length first gap section 28 begins at about 12 inches downstream of upstream wall 29 of furnace 6 second gap section 28 u2032 begins at about 24 inches downstream of upstream wall 29 of furnace 6 first and second projections 30 30 u2032 are removably fixed to locations on retort 4 corresponding to.