beachlover said:
I seem to recall that some years back,before disposable lighters were so available and cheap, prisoners used to use empty disposable lighters in which the gas compartment had been opened out from top to bottom and a length of old fashioned washing line type rope or rolled bedsheet threaded through to catch the spark from the flint. I don't have a photo, but dead simple to make and exactly the same principle really.
The main difference between a slow match (aside from the saltpeter soak) and the tinder tube is the brass tube.
If you snuff out a burning rope by rubbing it on something, or pinching it, you destroy the delicate charred fibres. It's these delicate charred fibres which make the rope easy to relight with a flint and steel. If you rub them off, the rope will be almost impossible to relight with a flint and steel.
So extinguishing the rope, by pulling it into the brass tube (it stifles it of Oxygen), preserves the delicate charred end. It can then be carried around in your pocket or in your pack for days - when you want fire, those very delicate charred fibres are still there, just as if you've just put it out.
The burning rope thing has been around in various guises, but the key thing here, is something that can be lit easily with a flint and steel and that's where the brass tube makes all the difference.