Thoughts from the Fourth of July

So as you know older watchers may know, I'm not the most patriotic American (see 'My faith in My country part 1'), but nothing makes more patriotic then the Fourth of July. No, not because we get to blow thing up, it just reminds me that 200 some years ago (231-239 years, but who's counting?), We Americans (with the help of the help of the French, Spanish, and Dutch) went up against the then largest military in the world, the British, and won, somehow... I always like to imagine that the fireworks somewhat tell of the story of the American battle for Independence, but what a smiley face has to do with it I have no idea.

"When you tell a Prussian soldier to do something, they do it; When you tell an American soldier to do something, they first ask you why? When you tell them why, then they do it." Baron Friedtich Wilhelm von Steuben on American Soldiers. Perfect von Steuben, perfect.
"Over here! Swear at him for me!" Also von Seuben

Another thought, not quite related to American Independence is this: How the hell do fireworks make all those fancy patterns? I understand how to make the different colors, that's chemistry in all that, but the nice perfect orbs and circles and even the smiley faces, how do they do that?