Hi Kronckew,
Thanks for that neat video of the atlatl. I keep promising myself I'll get one, someday.
I'm no specialist on the spearthrowers, but I think there's a mechanical difference between the North American spear throwers and the Australian ones. The old Midwest spear throwers were, as you say, optimized as a "two spring" system, where the spear thrower bent, the dart bent, and then they both sprung back in synchrony to store and release the energy, and make the dart really fly. They optimized the system by repositioning the stone weight up and down the shaft of the spearthrower, to change how fast it rebounded to mesh with the rebound speed of the dart.
The Australian spearthrowers--woomeras--are, so far as I know, rigid. I've seen a demonstration of the Queensland variety (similar to the one here), and the spear definitely bends. The desert woomeras are spoon-shaped and rigid, and I'm not sure if their spears bend or not. The one video I saw (from around Uluru) showed an aboriginal using his broad spearthrower sidearm to good effect, so that spoon shape might have some stabilizing effect that I don't understand (perhaps the edge of the spoon holds the spear level while the user throws sidearm). In any case, any spring action was confined to the spear, and the woomera is primarily a lever arm.
One thing I'm not sure about is whether the North American spearthrower is technically an atlatl, which to be picky, is the Aztec spearthrower used to good effect on Cortez. Presumably it is, but the few illustrations I've seen of the Aztec atlatl don't have the banner weight, so for all I know, the Aztec atlatl was built more like a woomera. Yes, I KNOW that atlatl is now an anthropological term. I'm just being picky
Thanks for showing this great item, Tim. No arguments that this one is from the Torres Straits (unlike that stone club
)
Best,
F