I always like stories of smart things having good repercussions beyond what was expected. There was a story a year or so back about the earliest known sound recordings, which were never meant to be played back. The creator of the “phonautograph” was merely playing with how voice could shake a pen that was making a line; it wasn’t until a century and a half later that someone figured out “hey, we can turn this line back into sound!”
I just ran across another of those stories, and it’s about an acknowledged creative genius, Méliès, the early filmmaker (if you saw the movie Hugo, you know the guy I mean.) Due to some problems with distribution, Méliès found that he needed two negatives of each movie. Rather than having two cameras that needed separate operation, he simplified the shooting: he built a special camera that was really two cameras in one, two reels of film, two lenses. Sure, they’d each get a slightly different image, but they were close enough that it shouldn’t make much difference.
You’re seeing what’s coming, aren’t you?
That’s right. a century later, someone paired the two prints back together, and got these early masterpieces in totally legitimate 3-D.