name this ancient weapon

Factual Questions
21

At first, I thought, Yeah! I’ve seen that too!

The more I thought about it, however, I couldn’t help wondering if I was mixing that up in my mind with an ancient Chinese invention that was like a box with no top or bottom, divided into square columns, each loaded with a gunpowder powered projectile. The entire assembly was aimed en masse and fired in a single (iirc) volley.

Wait, was that the device on Mythbusters mentioned above? Now that I’ve taken that turn of thought, I seem to recall that it was supposed to allow single shots, but that whoever had built the replica discovered that the fiery exhaust from one rocket set off the others in a chain reaction. Any of that ring any bells?

22

Just as an aside, the Mythbusters made a polybolos once, in the “arrow machine gun” episode. It actually worked surprisingly well, although it had a problem with breaking down a lot due to a lot of complex moving parts. Which I suppose would also have been a factor on an ancient battlefield, and a reason why an automatic ballista never conquered the ancient world.

Still, it was pretty awesome.