Surely you've seen the way the trains in wedding gowns are buttoned up to permit dancing. I assume it was something similar, except without the preestablished buttons and loops.

] ] Would they be pinning up each other’s train for dancing whilst in the ballroom, just to keep it out of the way...

] I remember a scene from the movie "Pygmalion" (1938, with Wendy Hiller) where the newly-elegant Eliza Dolittle moves onto the dance floor with just the kind of train that would get in everybody's way if she tried to dance in it. She gracefully picks it up and flings it over one shoulder as though it were a long scarf. Of course, hers is long enough and heavy enough to stay put and continue to look elegant at the same time (no hint of petticoat or leg). I remember it was a small "aha" moment when I first saw it, as in "Oh, *that's* what they did with those things!". I guess *pinning* it up would be a more reliable way of achieving the same goal.