Antique Bausch & Lomb Optical testing measuring Medical scientific equipment

Bausch & Lomb Optical testing measuring Medical scientific equipment antique vintage. This has parts made of many different materials; cast iron, steel brass, some plastic old plastic stuff and maybe copper. Please assume nothing works on this unit. I don't know anything about this unit. The overall approximate measurements are 17 inches tall, 31½ inches Long by 8 inches wide.

Bausch & Lomb Optical Co. Rochester NY" I'm not certain the patent number is read correctly, please see the picture as well "U. This is dirty Dusty scratched bent the chain has a loose end but I don't know if it's broken or what because I'm not sure of anything with this unit I did not force anything to move, I'm leaving that up for the new owner, certain things rotate and move and other things do not move easily, I did not force anything.

---