butt end 22 extends free of the second or outer pipe 40 as a gas flow cooled handle portion 60 by which the free end can be thrust into a furnace port to light the furnace the cap 28 lies within but free of the gable roof shaped structure 56 of the outer pipe 40 the slot in the outer pipe lies longitudinally between the 34 c 34 shaped baffles 34 36 which in turn lie between the vents 48 54 the spacer blocks 42 engage the featureless handle grip portion 60 of the inner pipe 20 in operation gas under pressure flows through the inner pipe 20 and emerges along the slot 32 in the inner pipe where it mixes with ambient air induced into the outer pipe 40 through the openings 62 between the spacer blocks 42 and through the vents 48 54 and through slot 52 in the outer pipe and turbulently mixed at baffles 34 36 and cap 28 when ignited burns both within the coaxial space between the pipes and emerges at the gable ends 58 shown of the gable roof shaped flame spreader 56 on the end of the outer pipe one gable end opening may be sufficient but two of these lateral openings.