I found this metal detecting today. It's made of brass. Does anybody know what it is?

So maybe something repurposed as a water level indicator . The spots on the side and it being flanged make it look like it’s supposed to be able to slide into something and be locked off at different spots

*surveyor's ruler

fake?

Yeah that's definitely brass. The more red the brass the higher the copper content. Red brass was used primarily from late 50s to late 80s but then copper prices went too high. I'm guessing it's a surveyor's tool from around then. That being said I would have expected much more tarnish if it was left out that long. Looks like no more than 5 to 10 years of tarnish. Maybe it was an older piece of equipment a modern surveyor was using then lost?

Looks like some of the measurements were added afterwards or that some of the numbers stamped are newer ?

I can't believe no one has said this: it's a ruler of some sort

This