This is one of a series of “Ultrix” cameras made between 1922 and 1939. This one has a cool design. To focus, the entire shutter and lens assembly moves back and forth on a large exposed helical gear.

I had to do some basic cleaning and lubrication on this camera. To get the focus working smoothly, I used some Helimax-SP, a grease intended for use on optical helicals.

These cameras were made with a wide range of shutters and lenses. The Radionar 4.5 10.5 cm lens on this one makes beautiful photos. I shot these on a walk in Concord, Massachusetts.