That surprises me - I thought they were a bit thicker than that - I know some of them are believed to have been cast in one piece (possibly with the knobs soldered on). I’d have thought a 2mm wll thickness would rule out lost wax casting.
Then again, maybe the delicate construction was part of the challenge - if they are a demonstration piece.
The simplest explanation for thin metal, I would think, would be reducing the materials cost. Though I suppose that that would be a tradeoff with labor costs, for making it more difficult to make them.
Though, how certain are we that they were cast in shape? If I were tasked with making such an object (whatever its use), I’m make each of the sides separately and then somehow attach them together (solder, welding, riveting to angle pieces, whatever).
Ink, or paint, that has long since vanished.
Cast hollow objects are usually fairly easy to recognise - because only the outside is usually finished/polished.
This one (found broken, so we can see the inside) is almost certainly cast in one piece.
This one, on the other hand, looks like it was soldered together from flat pieces.
Hm, the difference in construction methods would probably argue against them being masterpieces, then (or at least, not purely masterpieces), since there’d be no reason for the sheet-metal workers and the metal-casters to use the same basic design.
True, although we might be looking at a collection of several different types of object that juat happen to share some design features - for example: this one, although it’s dodecahedral and knobbly, doesn’t really look like it could do the same things that the big, hollow ones do (whatever that thing is).
Interestingly, when I did a google image search this time, there were some other similar objects - such as this and this - supposedly Byzantine, but looking related in design and decoration.
Is each hole a different diameter?
I’m sticking with tent pole hardware, much like modern shock-corded tents. Insert tent pole in large hole, tip seats in smaller hole on the opposite side. Knobbies are used to secure laces/lanyards to secure the tent fabric. It is such a mundane use, it would never be recorded.
I dunno, I wouldn’t be at all surprised if the Roman army had an official field manual on the proper way to pitch tents, and you’d think that they’d be listed in quartermasters’ records. Woe be unto the poor grunt who didn’t pack enough tent-dodecahedra and got reprimanded by his officer for it.
Also, something that intricate and hard to make can’t be for tent straps. Think of the cost.
It’s easy to see why these things have confounded everyone for so long - pretty much any explanation we propose has some immediate, major flaw.
If they’re astronomical or surveying instruments, why aren’t they more uniform?
If they’re taper gauges, why do they have knobs on?
etc
Do we have Roman manuals like that?
That would go for any military application, would it not?
How can I get a hold of one of these? We recently bought an X-ray computed tomography (CT) system at work. Would like to do a hi-res 3D scan of it.
Probably, at least for anything where the military used them themselves. I can see the argument that they might have been used in, say, spearmaking.
Most of the holes seem to be of different sizes, EXCEPT when they are all the same size!
Just to keep us honest, here is the link to the 2 mm thickness remark:
Its about halfway down the page. Mine is automatically translated to English, yours may vary.
That page has some more remarks there about mechanical strength, and the process that was used to make some of them. He mentions that often the cast ones had two excessively large holes lined up, and these holes often had rough edges. The others being finely drilled. In one case the object was found with a rotten bone in thiese two holes.
Its also possible this hole was used to hold the core in place during casting. A core is a specially made ball type shape of hardened, dried sand (now egg seal or sodium silicate decahydrate is used as hardener) that is held in place through the casting walls. When they cast car engine blocks these holes are filled with so-called freeze plugs. This might result in the two rough holes in our case. Probably wax is applied over the core and the fancier holes are drilled, and the outside is tooled, stamped with little star shapes in some cases, before the whole thing is embedded in sand.
Except when they are not cast but fabricated from flat metal pieces of course.
Pretty involved process and a fair amount of technology involved. Would have been state of the art more or less.
The author of that page also mentions that holes ranged between 6mm and 40 mm in size.
Also, that the two rough holes used in cast items might not have been visible when the object was in use. Like if it was placed on a shaft. Or in my opinion, if it was intended to be seen most of the time from the side, and they weren’t overly fussy.
Bosda Di’Chi of Tricor : yes they could have painted the sides to indicate which was which. The engraved circles around most holes would have held paint well. Although the pair of core holes often didn’t have these recessed lines, that is the biggest pair of holes.
::
WonderWheeler, just a note: you’re not honor bound to write new subject headers for every post, unless you really want to call to order wayward drifts to something important.
Just saying this to save you time.
::
Leo
Thanks, don’t worry. Too much time on my hands right now, and touch typing and auto-complete make the job easy. Pardon me if I get too wordy though.
Was just trying to keep things in order.
Regarding the tent pole explanation, the article that introduced me to these things made note of the fact that while they were found all over Europe, that it was unusual to find more than one at a site. This would suggest they were not something so mundane that everyone had one, or that they were created in large numbers like you might expect out of a piece of military ordinance.
Only one at a site sounds right for some sort of measuring instrument, I think.
Have any similar objects with variously-sized holes ever been found in shapes other than a dodecahedron? A prism shape, maybe? You’d think a prism would be easier to make, so if they don’t exist, the overall shape must be important somehow.
