I found this picture in an old book, "Man before Metal" by Joly, and thought it would interest you. Obviously the technique was to twirl the stick (fire drill) kind of like a hand drill or brace with the hearth board resting against a tree or suitable back stop. He probably has some form of socket (in place of the hand hold) resting against his chest. I wish they had gone into further detail because I never saw this technique before. If anyone has ever seen this technique done or knows more about it please let me know.
13 hours ago