The cylinder, which is four inches long, is fixed to a threaded mainshaft. A stylus tracking on the cylinder is attached to a carriage containing a wheel which follows the thread. The clockwork motor was made in Germany. Guesses so far are:-

A cylinder audio player?

A device for transmitting pictures?

A stenographer's dictation machine?

If you can help, please contact John Rose, who's details can be found on the SDRS information page.