Carl Zeiss S-Tessar f: 5.6 300mm barrel lens

Description

Massive 300 mm f: 5.6 lens by Carl Zeiss for unknown use
No iris, no shutter, just a really big 3 pound lens that may have
been designed for a projector or copy machine.
Focal length 300 mm, is approximately 12 inch
We tried using it for an 8X10 view camera, but nothing worked
so I call it the orphan lens, and a wonderful paper weight