I received a brass lens with some other stuff recently and I have attached a couple of pictures.
The only writing on it is 20146 engraved on the barrel (it could be 2014.6 or 2014-6).
It has a strip of obviously home made Waterhouse stops but the slot for them does not look home modified so I assume it always had waterhouse stops.
If it wasn't for the stops, I would think it was a projection lens.
It is about 1.25" diameter and 1.5" long. Focal length is about 8".
Any ideas as to its original use?