Large, round, and brass

[Jason H.]

This object was found over a foot down in a spot that was both a Civil War camp and a home site. There were many nails, china and glass shards, and an animal bone in the hole with it. My only guess is that it could have been a candle base, but it doesn't quite match the ones I've seen. The ring on top is thick brass, but the rest is very thin brass with an iron ring supporting the perimeter. Any ideas?
Thanks,
Jason