Yet another "X-ray" novelty--this time, 1901's X-Ray Cathodoscope

From Boyce's Monthly, June, 1901. I'm betting this is yet another take on the X-ray Wonder Tube.  "Tells time on watch through cloth"?  Possible meaning: The X-Ray Cathodoscope can see through cloth, at least when the cloth is covering the face of a watch.  That's my guess.  Actually, "tells time on watch through cloth" sounds like something out of a magic act.

Yes, the highly cheap paper is as yellow(ed) as it appears in the scans.