So possibly someone came close by using a hard wood pointy stick to bore a hold in soft wood, or maybe along the lines of **dracoi **or Sam Stone’s posts they first had the idea of friction creating heat well established in their mind first. Either way the first fire started that way must have been through deliberate effort working from a principle, and then eventually someone got the wood hot enough to ignite. Accidentally starting a fire with wood on wood friction for some other purpose still seems unlikely to me.
Have you ever done woodwork? I’ve burned myself on hot wood more than once while sanding, filing, or cutting it. People who used flint knives to carve and shape wood no doubt discovered very quickly that it could get hot in the process.
My only attempt so far to start a fire with a bow drill failed because of my choice of wood. I’d cut down a decorative bush on my property that had died overwinter and decided one piece of it would be good for a spindle. I had a hell of a time cutting and shaping it, presumed my knife was dull. Turned out that this unassuming bush had wood as hard and dense as tropical ironwood- it made oak look soft. This was vampire-stake material.
I have started fire with a magnifying glass and dry grass; in fact I was surprised I got a flame directly instead of having to fan it.
I’ve gotten quartz and steel to make a few sparks but so far I haven’t been able to get sparks consistently or light a fire with it. I have used a commercial “flint” to get flame directly from nettle or milkweed fluff- the stuff goes up like flash paper and you have maybe two seconds to catch your next-coarsest tinder, but it beats char cloth by a mile.
If you don’t have a magnifying glass or other suitable lens, a magnifying compact mirror will work. You can orient it by looking at its shadow- if the shadow is round you’re pointing directly at the sun.
Paper and cardboard only burn at the edges. If you use a pair of scissors to fringe it it will burn much faster and easier. In general the more finely divided the material, the easier it is to light and the faster it will burn. I’ve gotten great results from cut-up dairy cartons. Altogether, anything with oil, grease, fat or wax burns much, much better than wood, paper or cotton, which only flame briefly before carbonizing.
There are temperate woods known as ironwood, too, you know. Around here, that name is most commonly given to a variety of hornbeam, but although that’s a small tree, I wouldn’t describe it as a shrub (it still has a single straight trunk, and grows up a ways before branching).
I don’t know; my wife says it was an “almond bush” although that name applies to a lot of different plants.
Olea capensis is the ironwood I’m familiar with, it tends to be quite shrubby. But it’s an olive, not an almond.
I imagine another advantage of wood is that if you have little fragments of wood that are heated up to the ignition point of wood, they’ll, well ignite, creating more heat, rather than immediately starting to cool as stone would.
Obviously, that’s not necessary, since flint and steel does in fact work, but I would think it helps.
I’ve worked with wood. Usually if it’s hot enough to burn me, I’ve used a power tool to get it that hot. Something they didn’t have. I too am skeptical that worked wood getting warm would equal fire in early mans mind. They surely experienced warm stuff in other way. Rocks laying in the sun might get too hot to hold for example.