[Lucius Cornelius Sulla]

I always thought the Fire of Orthanc was gunpowder. But if it were a metal like phosphorus, it would work in water

I always thought that the Fire of Orthanc was like Greek (Byzantine) fire, exact composition still a successfully guarded military secret. Thought to include both sulfur and charcoal, it could float on water and keep burning, very nasty in a battle with wooden ships. Probably gave the Empire an extra few centuries at least.

[JenB]

See, I always thought it was some nasty magic stuff, really, but I'd voted for Greek Fire over gunpowder.

[Overtaxed]

I was thinking along that line. I guess Saruman had Doppler Radar to know that he would need it at Helm's Deep.