SCUTUM, building and testing, some thoughts

[Matt Lukes]

Lion's share of strength... I disagree.
All factors are crucial, not equally crucial: glue type, glue quality, presence or absence of fibers, materials used to skin the scutum, its chord, its laminations as "plywood", varieties of woods.. some may be a greater part of that lion's share than others.

Sean, your suggestion was that the grain of the wood was the most significant factor- since you believe that the wood you can get presently is so much less tight-grained than that which was available in antiquity, you can't consider any tests you do accurate with respect to how original scuta performed. I suggested it was the fact that the scutum was a plywood piece- thin strips glued together alternating grain directions- is far more significant a factor. OF COURSE the strength of the glue, and the additional elements made a difference, but that's irrelevant to your statement and mine. You have to PROVE that the wood from which real scuta was made was significantly different from ours for your suggestion to be considered valid.

First, I do not believe that there were requirements.

Well what would you call your suggested "selected wood for appropriatenes for scutums" (sic)? Sounds like you mean there were requirements they tried to meet for grain, etc. I agree- suggesting that there were stringent requirements is unlikely and would most definitely have to be proven.

It seems quite clear by the evidence that scutum makers knew that a stronger less flexible vertical core laminated between two layers of more flexible more compressable species was the best way to make a scutum.

And what evidence is that? Does James mention mixed wood scutum artifacts in his book or is there some other mention of that?

It makes no sense anyway- you wouldn't want one layer to be stronger than the other because otherwise the scutum is weaker in one direction than the other. In fact, the fact that the outer layers are horizontal suggests that impacts that would flex the shield laterally were the most common or necessary to protect against.

Thus, I can see selection happening especially if selection is possible. Why not? It's practicle.

If possible- yes, but you wrote it as if it was a universal fact Sean. Sure if he could a scutarius would choose good wood- but, again, if the requirement were for hundreds or thousands of scuta, any significant selection would be impractical. Not only that but you're not taking into account the fact that for an army in the field for years, materials would be what was at hand- yes? If replacement scuta were needed, they had to be constructed as best as possible- meaning no excessive selection, if that was ever done in the first place. Once again, if you're going to state that you think it was done, you have to have evidence of it. A proper theory is generated FROM observations- to explain them. Unless some scutum artifacts show extremely tight grain, or other features suggesting they're select woods, your suggestion is completely unfounded.

I can see trees grown specifically for use in making scutums. Growing wood for specific purposes is something that's been done throughout history. Why not something as important as a military item?

hock: Evidence? Is there even a hint of this written, described, etc. anywhere?

A good wood worker always picks the best parts of a tree for his needs if he can. I use clear ash for pilum shafts, but if after milling into usable lengths and widths the grain does not run right or if a knot is in just the wrong place I reject it. When I select 2x4's at the lumber yard they dread me. I pick the best pieces. I often bring a tool to snap the metal band around a stack of lumber so I can have access to more choices... not all 2x4's a are created equal!

This is exactly why a great deal of excess selectivity isn't practical- if there's only so much useful wood in each tree and there's no industrial supply like there is today, it makes no sense at all to expect the kind of selection that goes into fine furniture for a purly funcitonal item that needs to work not to just look nice.

The addition of sinew fibers and the rough face for increased gluing area I understand, but why would you want to glue the strips wet?

That's easy... first I did not state wet wood I said damp. When wood is damp it absorbs glue better. When wood dries water is drawn out, but when you're gluing you want the glue to penetrate into the wood for better adhesion. As the dampened wood draws the water in it also draws the glue.[/quote] Fine- semantics. But do you actually mean that the dry wood absorbs the water from the glue causing it to gel faster and thus preventing it from penetrating as much? Because if dry, wood absorbs water readily, but when damp it does less so because there's already water there- basic diffusion dynamics. Well that does make some sense, but have you actually proved this or is it just a theory? I seem to recall trying it myself last September and finding it not as strong a joint as with the wood being dry...

No one has to join our yahoo group. Some photos are posted on Roman Army Group as well. The photo essay will appear on the Legio IX Hispana web page in due course.

Twice at least now you've made announcements with a suggestion that pictures can be seen on the Yahoo Groups page Sean- and you can't see those without joining the group. Thanks for posting them properly here to go with the threads :wink: