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So many chalk scribbles trying to figure Phoenix’s proboscis!




Rectilinearists will have to forgive us our curvy parts. This is the part where catapult-makers get to be all artsy; a chance to reveal our finely extruded sensibilities regarding shape and form. It’s a small role, so we have to make the most of it.

Next:  From the great cherry tree that is the historical record, I’ll mix me metaphorical fruit and pick this fat little plum.


forend aaa


A twisted piece of logic to be sure.  Much like the twisted double perspective prevalent elsewhere on Mr. T’s phallic offering.  Blue is the nosepiece.  Red is the trace of an inswinger limb….   (wink, wink, nod, nod, etc.)

According to my phantom adviser:  for obvious reasons, inswinger technology was a closely guarded military secret by the Romans.  Outright public depictions of it could result in severe penalties for the artists involved.  He muses how it has always been a black-robed technology.

Phantom advisors are so helpful.


When you finally see the light and give up on all this outswinger silliness,  you will have learned the irrefutable mechanical logic of the inswinger design.  (Tongue in cheek alert.)




You might like to try clicking on these photos to enlarge them.  Perhaps let your eye root around inside the design a bit.  If you cannot sense how this geometry oozes with pent up kinetics, just waiting to be exploited after 1700 years of being buried, then perhaps this game is not for you.




Honestly, I don’t know why I try, if you are going to be so bloody-minded all the time.   By any practical judgement, isn’t it obvious that something along these lines is how the artifacts were meant to be put together?  Why can’t you submit to the logic of how neatly the Elenovo and Orsova artifacts reveal themselves as inswinger’s?   Compact! Accurate! Powerful! Deadly! Let them out of your ivory closet already yet!

And if that doesn’t do it for you, stay tuned as we get this baby strung and kitted out for action.


I have been looking forward to implementing this plan for connecting the struts to the kamarion for some time now.

k yoke

I have not the slightest doubt that certain fellowes I know will be rolling their eyes, and wonder why I don’t just rivet the strut to the kamarion by utilizing those two little holes evident on the Orsova artifact.  Other than the need to make these parts thematically consistent with the take-apart strategy implied by the loops of the kambestrion and the tangs of the kamarion seen in the artifact record, I do not believe the rivet size suggested by the aforementioned holes would be adequate to handle the stresses that occur as the machine vibrates at the moment of firing.  Just my opinion, of course, but one I stand by having seen Firefly jiggle around with so much enthusiasm as she is fired.

Those two little holes for connecting the strut to the kamarion seen on the Orsova, are huge clues if you know how to read them.  I defy anyone to come up with a stronger and simpler take-apart design for connecting the strut to the kamarion than the one I’m about to implement.  Flat plate with a projecting pin? Relying on the rearward bend of the kamarion to hold it all in place?  Not so much, I think.  Think mil-spec reliability and you’ll understand where I’m coming from.

After a bit of finish work on her metal parts, I assembled Phoenix today to take a look at some possible stock profiles.

(Click to enlarge.)


Naturally Oona thinks all the fuss is about her.  Fashion models! ….waddayagonnado?

NTS:  Remember the youtube dude with the rolling pouch technique for shooting his slingshot. A similar style of spin casting may be possible with glandes fired from an inswinger.  ……Perhaps with a pivoting pouch, rigged inside of my usual twin line bowstring.  Wooden sabots could have different angles to force the twist in the pouch, and by this means produce various rates of rotation.  Whirring beasties of doom!  Terrified Gauls in the hinterlands, and all that.

….. Or, not.

GS dogs

’nuff said.

Because for some folks, linguistic ambience is everything, I’ve decided to call this hunky brute: the “Sagma”.  According to the Google, that’s Latin for saddle.  All very erudite and tickety-boo, I am sure.


The sagma joins the stock and the ladder together with great strength.  Note how the tight inside corners of our new sagmae, mimic the sharp rectilinear lines of these exact duplicates of the Elenovo kambestrion, seen below.


That’s thematic extension, Baby!  I will sandblast my sagmam to get a matte finish as seen on these kambestrions.  (Or is that kambestrium?)

Ain’t Latin the shiz, though.

My research accomplice in all things inswinger,  Mr. John Payne, has kindly forwarded this paper by Mark J. Schiefsky.   Technē and Method in Ancient Artillery Construction: The Belopoeica of Philo of Byzantium.

Click here for the paper:     philo_final_proofs_2015-01-29

It contains an excellent synopsis of Philon’s wedge machine.

There is also an extended treatment concerning the usefulness of the spring hole diameter in figuring the proper scale for making a torsion engine.  Our work on the Elenovo machine has utilized both the spring hole diameters and the height of the kambestrion to make size comparisons between the Elenovo and the Orsova machine.

The upshot of these comparisons is that, for our purposes, we will consider the Elenovo machine to be roughly three quarters the size of the Orsova.   (.729 to be needlessly exact.)

The Orsova machine is vital in our work on the Elenovo because it’s only surviving kamarion gives us a clue as to how far apart the two kambestrion are on an iron frame ballista.  Similarly, the Lyon machine gives a clear idea of the spring proportions because it contains not only the spring holes in the kambestrion, but also the washers and crossbars.  All vital for deducing the spring height.

And so, while the spring hole diameter is very important in fixing the scale, it is not the only dimensional consideration when making an artifact based reconstruction.

In short, I believe there is enough dimensional intelligence in the various artifacts we have to look at, to get a clear idea of the relative size of the primary components in an iron frame ballista.  (Other than the case* length, and consequent draw length, which are largely unknown, and must rely on experimentation to figure.) This approach is different than trying to apply the theoretical optimums that can be calculated from the ancient formulae for scaling a machine.  All of which are from a prior epoch in catapult development than we are working on, and clearly do not refer to late model, iron frame, inswingers.  (And no! Heron’s little garden toy doesn’t count.  If the translations of his work are as top-notch as I suspect they are, then it’s of no account here because Heron’s little baby was an outswinger anyway.  “Not our department!”, says Werner Von Braun.)

Given the errors that can accrue when making decisions based only on ancient formula, no matter how esteemed their pedigree, I prefer to stick with the things actually dug out of the ground.  In the end, this approach seems more in keeping with my trial and error, workbench methodology.

*Previously referred to as the “stock”.




From Murray’s website comes this next photo.

The three types of people:


Gun control


Here is another version I’ve had hanging on my wall these last few decades:


wolfie 2


(1)  Bad Wolfie!

(2)  Hapless Sheeples!

(3)  The strength to protect the innocents, without letting that power turn you into something like the monster you’ve just defeated….





The internet machine just produced this high quality looking work by Professor Wilkins et al.


Wilkins 1


And now to beat upon the dead horse:

Based upon my experiments with Firefly, it is my contention that if this ballista is run at high enough levels of strain to produce any meaningful performance (e.g. several times more powerful than a hand bow, 600 plus yards etc.) then the cords that wrap over those squarish corners on the crossbars would be severely damaged after only a hundred shots or so.

Even if our experiential evidence in this matter is not convincing, a quick thought experiment should settle the matter.  Which spring do you think would have the better longevity?  The one that wraps over a crossbar with squarish corners and only a small radius on it’s edges for protecting the spring cord?  Or the one that wraps over a crossbar that has a full radius on it and where the stresses are much less focused?

Just ask a rock climber or fisherman or any kind of professional that actually works with ropes — when there are serious stresses involved, obviously the full radius version gets the nod for being rope friendly.

So again, what’s with the square crossbars with minimal radii on the stress points?   If you are familiar with all the artifacts, clearly these squared-off jobs are part of the historical record, as are the full radius versions.   They had them both. And yet, it’s not like the Romans would be afraid to cough up the extra work to make the square ones properly rounded.  With some simple forging and a spell on the grinding wheel, putting a full radius on a crossbar is not difficult to do at all.  I just don’t figure square crossbars without some extenuating explanation — like Philon’s wedge thing I keep beating on about.

Probably none of this seems remotely important if you have never made and operated a truly powerful torsion engine for many hundreds of shots.   If you have,  then perhaps you understand why I consider this whole discrepancy a fairly major clue.

Croak goes the horse.


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