I needed to make some char cloth for the flint and steel demonstration that I will be doing in a couple of days. All you have to do is put small squares of cotton cloth in a tin with a hole in the top and then put it on the fire. The heat drives off the volatiles leaving behind cloth that is made out of charcoal. The cool thing is that the volatiles being driven off are flammable. Here the little volatiles stream is on fire. Neat.