I found this on a vacant lot, gave a heck of a hit, being all copper! I have a nickel on top of it for size reference, but the "can" is just about the size of a tuna fish can. It kind of looks like the top part may come off, but the item is empty. On the side, it has a spot where it may have been attached to something. One of my friends said it may have been a float, like a toilet bowl float??? Your ideas will be appreciated.