Unusual notches on very old boomerang
 

just recently acquired this old boomerang which was collected from Australia in the 1920s and was known to be an old one then , what I cant figure out is why it has notches/tally marks cut out on one side , I don't think this is a fighting boomerang , maybe they were to represent important ceremonies ?
any info would be very welcome

Could these possibly be tally-marks used to keep count of animals taken when using this particular piece for hunting? :shrug:

Best,
Robert

hi Robert , yes I did wonder this , but then I thought a boomerang of this age would of maybe taken more animals than this , I'm not sure ,difficult to know , I havnt seen any other boomerangs with similar marks ,
thanks for your reply

Nice stone (?) carved boomerang! :) Sorry can't be from help by your question. :shrug:

Could they be for aerodynamic speed and lift?

Vortex generators are often used on the leading edge of aircraft wings to permit the wing to operate efficiently at low speeds. If these notches have a similar effect, it would keep the boomerang flying at lower rotational speeds, presumably.

Vortex generator:
https://en.wikipedia.org/wiki/Vortex_generator

Yeah..........what Bob said........ :D

I dont think so, because the notches are on the trailing edge, not on the leading edge.

I simply think, the notches are either a kind of simple decoration or (better idea) made for more grip during the throw.


Roland

yes I agree , the notches are on the trailing edge

When an object is spinning, I'm not sure one can say that there is a consistent leading and trailing edge.

As a kid growing up in Australia, I played with boomerangs and knew a few aboriginal kids that I would see on summer holidays along the eastern Victorian coast. The manner of throwing a boomerang is with the concave edge forward, at least that is how the aboriginals throw them. The fingers therefore grip one end of the concave side. The notches on this example are on the end of the convex side, and therefore would impinge on the palm of the hand--that could be uncomfortable and would be of no advantage in gripping the boomerang. This manner of throwing the boomerang is used for the ones that return to the thrower. I'm not sure that the same technique was used for hunting boomerang, which could be the opposite. The boomerang shown here is not markedly curved, like the returning examples, and the straighter ones are usually described as "hunting" boomerangs that were often thrown more vertically than the returning type, which are thrown at an angle of about 45 degrees to the ground.

I don't have an answer for what the notches represent, but they probably were not helpful in gripping the boomerang to throw it. Perhaps our resident Aussie, Alan Maisey, may have a better idea what they are for.

Ian.

I just compared the boomerang to a one bladed fan with an axial impeller. Now I`m unsure.

From the aerodynamic point of view, the notches will not have any postive effect. The boomerang is spinning and flying too slow, for a measurable result (imho).


On an axial or radial impeller such notches can reduce the turbulences and increase the degree of efficiency of the impeller. No one should laugh about this, I have a patent for notches on impellers.

So the idea of the aerodynamic improvement is really good from the technical point of view (state of the art for fans and compressors)


Roland

Hi Roland:

Yes, I think a rotating projectile is likely different from a stationary fan. Both the axial and linear speeds are probably important, but my college physics is a long time ago. :(

Ian.

Ian, I'm afraid I cannot assist with any specialist knowledge on boomerangs.

I do live in an area that has a very strong Koori presence, and a living Koori culture, I have neighbours who identify as Koori, I have friends who are Koori, many years ago (notably when I still had some influence in public service circles) I was invited to acknowledge my (non-existent) Koori roots.

But I do not have any specialist knowledge of boomerangs. Sorry.

Thanks Alan.

bit of an old thread.. but these are not anything more than to increase grip druing the throw at a later date than the time it was made.
if the maker was the primary thrower they woudl have just adjusted the hape for their grip,
you can see little knife marks on clubs , karlies and boomerangs for improved grip many times.. also some boomerangs are thinned down at one end by the thrower at a later date.. so the original owner made it one was and the new owner found it to wide or slippery.

lots of old throwing clubs will have scraping, patterns our gouges on their pommel and lower portion of the grip to allow more control when thrown too.

aborigines liked throwing stuff , almost every manner of weapon or tool can be thrown at some point..and i guess what throws well for one person might not feel as good for another.

Maybe there are marks on one side in order to properly take the boomerang for a throw without looking at it?
Without taking your eyes off the target?