This is something I've been experimenting with since early spring. The magnet I use has a pull of around 250 lbs. So far, (since I'm into older items) I've been targeting major creek and river crossings during the 1800s by finding old maps, especially civil war maps.
This past weekend I decided I'd take the magnet to 3 historical bridges in my area. The first was a covered bridge built in 1901. The second was a bridge that was burned during the civil war and the third was down from a grist mill that fell under artillery fire during the civil war. The first 2 locations indeed produced some iron, but it wasn't until my last stop that me and the kiddos got into some really nice and really old items. If any of you old timers see any thing that rings a bell, feel free to let me know what the item might be.
So far, the two wheels I believe are either from a wagon of a model T ford. The pear shaped item, I'm positive that it's an old grain weight. The long blade that my daughter finds, I'm not sure of the proper name but I called it a sickle or a scythe.
Let me know if you see anything worth going back and grabbing.
The items I threw on the bank I took with me but there's no way I could take all the items I find with a magnet with me. We're talking hundreds of pounds of iron. The items I don't keep stay wherever I initially find them.
The part right after your daughter was messing with the magnet....you thought it was something then fields it quickly and that was it..looks like something used for horse work...no idea on the names of such things..but the shape of it looked familiar...