York2024-422. INCLINOMETER. Bradford Union. These levels with their distinctive semi-circular central vial were patented in 1904 by John Happle, and most of them were sold by the Bradford Union company of Bradford, PA. This is a typical example, 24" with cherry stock and aluminum rails. They all have a central hole which according the patent was intended to mount them on a fork for use as a sighting level; we've never seen one with its mount. Nice and clean with intact vials. Good+ 150-300