I found a bag full of strange glass tubes in my late uncle’s bedroom drawer. I have no idea what they’re for, but I’m really intrigued….
You might have found small glass tubes containing three tiny ball bearings. These aren’t random trinkets—they’re precision components from antique spirit levels, often called bullseye or machinist’s levels. What They Are Unlike standard levels with a single bubble in a curved tube, bullseye levels feature a circular, dome-shaped capsule filled with liquid, measuring levelness in … Read more