[davem]

Who made the fireworks?

The bells of day had scarcely rung out again, a mockery in the unlightened dark, when far away he saw fires spring up, across in the dim spaces where the walls of the Pelennor stood. The watchman cried aloud, and all men in the City stood to arms. Now ever and anon there was a red flash, and slowly through the heavy air dull rumbles could be heard.
'They have taken the wall!' men cried. 'They are blasting breaches in it. They are coming!'

This is the 'blasting fire' of Orthanc which breached the wall of Helm's Deep:

"But the Orcs have brought a devilry from Orthanc," said Aragorn. "They have a blasting fire, and with it they took the Wall. If they cannot come in the caves, they may seal up those that are inside. But now we must turn all our thought to our own defence."

So, was Aragorn right? Was it Saruman who invented 'gunpowder', or did he learn it from Sauron?

Or did Gandalf start the whole nasty business off - he's the one who's famous for fireworks after all?

Gandalf seems, on the face of it, the most likely candidate - he was the bearer of Narya, the Ring of Fire. Is it possible that Gandalf's little toys inspired his fellow Istari to come up with the explosives used at Helm's Deep, & that Sauron then obtained the knowledge from him via the Palantir?

Whatever the answer it seems that this 'blasting fire' was less of a shock to the Gondorians than it was to the Rohirrim. Its appearance at Helm's Deep certainly seems to have thrown the defenders into confusion, whereas the men of Minas Tirith appear to see it almost as a 'standard tactic' of Sauron's forces - they are not stunned into silence by something totally unexpected, but know that a 'flash' & a 'dull rumble' in the distance means explosives.

A more interesting question is how far away they were from creating cannons? Probably not far. It seems that the defeat of Sauron put an end to the development of firearms. That technology dies with the defeat of Sauron. The West does not take it up & make use of it later - even for self-defence. I don't know whether that was Tolkien's comment on the use made of Nazi rocket technology by the allies in the post war period, but it certainly points up a difference between the victors in the War of the Ring & the victors of WW2.

Another interesting weapon is the incendiary 'bombs'. As Lalwende says:

And what about the secret art that caused the missiles to burst into flame as they landed? Could they have been incendiary devices, filled with unstable compounds?

Tolkien seems to be referring to something like Greek Fire. Again, 'high-technology' weaponry is being employed against a civilisation armed only with swords, arrows & spears. Clearly, the West would stand little chance of survival if the Ring had not been destroyed, but I think there is perhaps a deeper theme underlying the West's refusal to use this kind of weaponry. It is like the Ring in one way - use of it will corrupt the user. Just as one cannot use the Ring without becoming like Sauron so one cannot use the 'lesser' weapons of the Enemy without risking a similar fate. To behave like the enemy requires one to think like him, to think like him is to risk becoming like him. The promise of easy victory is what lures one to the edge of the abyss. Just as the West must reject the Ring, so it must reject the use of 'blasting fire' & incendiary devices.

Of course, that's fine for a fantasy world - things are different in the 'real world' aren't they?