Dug this in the woods it is copper or brass appears to be a water filter maybe. The hole on the top is threaded looks like half inch.
At the very least its interesting and in good condition what ever it is.
Looks like a pump pick-up screen, and at that size, I dunno, maybe a water fountain?
Edit: apparently I was typing too slow again, but we're all thinking basically the same thing: the little legs are for having it sit near the bottom of a water source thats being sucked up for some reason.
Looks like it could go on the top of a rock or brick chimney. Is too small for a single vent, but was possibly used with 2 or more others. The weight would keep it in place, but the wire netting would keep birds and animals out. ...Just guessing.