Plumbata

[ambrosius]

Why do you try to distinguish between the weight of a metal head (large or small) and the
additional weight of the lead on a pilum or plumbata? The latter is just an extension of the former, with both intended to keep the projectile flying straight.

No, I'm afraid not. The added weights of a pilum and a plumbata have nothing to do with their trajectiory, but everything with the force needed to smash trough a shield or armour. You seem not to understand the difference between a pilum/plumbata and a javelin.

:roll: No Robert, I'm afraid it is you who don't seem to understand
the difference between a pilum, plumbata and a javelin. For a start,
a pilum IS a javelin, as it's designed primarily to be thrown,
rather than thrusted. And yes, before you argue yet another academic
point, I said primarily. We all know spears could be thrown,
just as javelins could be thrusted. But that's not how they were
primarily designed to be used.

How many different plumbata have you actually tested yourself? I'll say it again - I'd like to see some pictures of you testing plumbatae. How do you throw them?

And I'll say it again. 8) The weight of both the iron head and
the lead 'weight' contribute to lead (that's the verb 'to lead', not the
name of the metal) the plumbata in flight. Yes, on impact, any added
lead weight on a pilum or plumbata will help with penetration. But
that point has already been made (by me, I thought) in addition to
the point about the weight at the front of a projectile being necessary
to give it the desired attitude in flight.

I know that you feel your assumptions make you a scientist, as you
have said. But what a scientist actually does is test his assumptions
by experimentation. So here are some suggestions for experiments
you can conduct to see who is right about the function of the lead
weight on a plumbata:

1.)Construct two plumbatae. One without the lead weight and one
without both the lead weight and the iron head. Then try throwing
them in exactly the same way as you do your 'normal' plumbata.
Report back to us all on the different trajectories that you observe
in flight.

2.)Try throwing your existing 'normal' plumbata in exactly the same
way as you usually do, but holding it at the other end (the iron
head won't cut your fingers, trust me :twisted: ). Now watch, as
despite you releasing the plumbata tail-first, it magically rights itself
in mid-air, as soon as you let go of it, and spins end-over-end just
once, till it is flying nose first.

I've tried both the above, myself, btw. 8)

When I previously described the motion of throwing a plumbata, I
was actually describing the minimum arc through which your
plumbata will travel (180 degrees) before you release it. You have
since described that your own preferred method is to wind-up like
a helicopter preparing for take-off (that is, through 360 degrees).
That's fine. It won't actually increase the range of the plumbata by
much, and will only increase the amount of angular momentum you impart on it at release, which would tend to make it spin end-over-end (the problem we've been discussing) in the absence of the lead weight. The point is, whether you throw over or under-arm, the plumbata is passing through a minimum of 180 degrees. That is what would
make the plumbata spin end-over-end without it being nose-heavy.
Happy chucking. :wink:

Ambrosius/Mike