Vintage radioactive wrist watches

Vintage watches from the 1910-1920 era could use a paint based on radioactive material like Radium to excite another fluorescent material in order to emit light.

This paint was used on watches hands and dials like this one:

Building a Geiger counter based on a SBM-20 GM tube and a popular arduino project:

Testing the Radium from the watches hands - 6798CPM and counting...

Slightly radioactive CRT: