I used to collect magnetic ore from sand using magnets in childhood. If magnets were available in history, then a certain tribe didnt have to pimp their women to obtain iron nails from sailors who ripped them from the very ship they were supposed to maintain, or modern western countries didnt have to burn down barns to recover nails.
As a kid I was fascinated by the extraction of iron from sand using a magnet. I’d hang out in sandboxes on playgrounds and collect it. I figured out you could wrap the magnet in a plastic bag for easy removal of iron filings. Last I recall I had filled two and a half peanut butter jars.
Same in Germany. I never considered magnet fishing growing up there and now I remember why: it was super common for WW2 explosives to be found that didn't explode on impact but had corroded over time.
Dad sold veterinary supplies. We had lots of these to play with. They were the strongest magnets around before modern rare earth magnets came along. Sometimes we used them to clamp steel pieces together prior to welding etc. Lots of uses.
Having sweeped some area with a magnet already to find sharp stuff harmful to grazing animals: rather unpractical because either you need a ridiculously strong magnet (to the point it becomes dangerous to handle it, moreover in areas with ironstone it attracts huge amounts of tiny debris), or it needs to be only a cm above the surface. And not all screws and nails are magnetic.
When I was about six, I had a powerful alnico magnet to play with, and I remember being quite intrigued that dirt would stick to it. Not all dirt, but some dirt. At one point I had a small jar full of magnetic dirt, collected by sweeping the magnet thru dirt and scraping off whatever sticked. As I recall, the magnetic dirt was darker in hue than the grayish non-magnetic dirt.
> I recall that they were not very strong magnets.
I have one on my desk right now, and it’s pretty strong! They’re historically made from Alnico alloys, which were the strongest type of permanent magnet until rare earth magnets were discovered.
My local co-op had them as impulse items at the checkstand. I seem to remember them costing as much as a candy bar, and my parents giving in and getting me a few. IIRC, they were slightly stronger than ceramic magnets, and much less brittle.
Although I must admit - I grew up at a time when magnets were anathema to using computers, and I remain resistant to having magnets anywhere near my work area.
For a basic magnet, there was an old science fair type of experiment where you laid the magnet on a piece of photo paper, sprinkled iron filings, flashed the paper and developed. Of course, these days you can just basically shoot a digital photo of the magnets and filings. Lots of examples online.
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