Tom Stovall wrote: (clip) Turn off the air, quit cranking, stop pumping the
billows - it's lit. (clip)
^^^^^^^^^^^^
Tom's description sounds like it ought to help, but I would like to add one
little thing. In order to picture the process, you have to know that the
damp coal, as it heats up and catches fire, forms a crust--the chunks stick
together. This is going to form an "igloo," with hot burning coal on the
inside, with air flowing through it, and damp coal on the outside, waiting
its turn to get to the inside.