It has been noted by some, that Firefly is a tad over-engineered.   Compared to what?, we would like to know.  As our machine appears to be the only one generating authentic levels of performance (shooting 800 meters across the Danube etc.),  perhaps it would be more accurate to suggest that all other modern reconstructions of her size and class are actually under-engineered.  Firefly was never intended to be put on parade at a reenactment event and nit-picked by all those worthies that have already assembled a keen vision of what a late model, iron framed Roman machine must have looked like,  (although surely they appreciate our accurate dimensional reconstruction of the Orsova artifacts).  Firefly was made largely as a test bed, and in that sense I suppose she is a dither or two overwrought.  Her talents are weighted more to the shooting range, and generating all the events and observations that have been so painstakingly presented in this journal.

Little things like:

Repeated groupings of three and more consecutively fired Dura bolts inside a twenty foot circle at a range of 880 yards;  firing a flight bolt 1,000 yards (okay, 998 yards, but near enough to that iconic distance);  understanding that the authentic, 7 1/2 degrees of rotational discrimination in the washers is just about the right fineness of control needed to preload the spring bundles into a state of balance; observing how the aerodynamic pressure on a truly fast moving Dura bolt stabilizes it much more quickly than a regular straight sided shaft; proving the necessity of angle struts to make the machine rigid enough for heavy draw weights; demonstrating that with an inswinger there is plenty of power potential in 45 degrees and less of arm rotation, and from this realizing that the original Orsova machine could have been as short as 5 feet, rather than Firefly’s 7 1/2 feet;   proving that a sliding trigger block is a practical and desirable alternative to a long and awkward slider of conventional design, and also showing how this might be a viable interpretation of certain depictions on Trajan’s column;   having a muscular appreciation for the cocking effort;   punching 1/2″ diameter holes through 1/4″ steel plate;  taking a  quarter-kilo bolt up to 400 feet per second;  generating 2,000 foot pounds of muzzle energy;  having multiple witnesses observe the parabola of a half-kilo bolt as it travels an estimated 300 yards up into the air, and a carefully measured, 820 yards downrange; putting 11 consecutive shots through a two inch hole at fifty meters; seeing how easy it is to swap bowstrings and use one with a pouch to fire 400 gram lead glandes at over 300 feet per second, and then using the same pouched string to fire loads of grape shot;  demonstrating that a modular, pre-wound torsion spring can be installed into a field frame in less than half an hour;   dealing with chaffing issues on the spring;  understanding where the potential wear points and weak spots are in the machine when under repeated heavy loads; tuning the machine to eliminate all traces of erratic bolt flight;  dealing with the whip arch in the bowstring at the moment of firing and preventing it from tangling under the stock; demonstrating how the two holes in the kamerion were likely used to support a front sight;   having multiple witnesses observe what an authentically flat trajectory with a heavy bolt actually looks like;  having multiple witnesses observe the very high precision and long range of Firefly’s indirect fire;  tuning the bundles so that the limbs sweep in the correct plane;   showing that by firing Firefly for a couple of hundred shots on a broken strand in one of the bundles that waxed 1/4″ , 3 ply cordage does not necessarily unravel or lose power by the diminisment of a single strand, (an obviously important consideration for the muggins that has to work the maintenance shift);  making and testing ten different variations of limbs to arrive at something fast and reliable;  enduring multiple limbs breakages and risking life and limb in that process;  using an experience and work bench methodology to achieve results rather than a limited mathematically based one, (ie. the way the Romans would have done engineering);  providing lots of evidence that the Orsova artifacts make much more sense kinetically when configured as an inswinger rather than a outswinger.   And finally,  let’s not forget our current project:  modelling the propulsion characteristics of both sinew and nylon torsion springs so that accurate predictions about the performance of original machines can be made with modern reconstructions.

I could go on.  But what’s the point?  If your definition of “authenticity” in an experimental archaeology project doesn’t include factors like this, it is clear our wavelengths are never going to merge.

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