Quote Originally Posted by mklotz View Post
The side of the dial shown in the photo looks more like a lunar phase calculator. In fact, the movable arm says "La Lune", French for "the moon".

As the arm is rotated to a particular date, the circular cutout in the rotating arm may move over darkened areas under it, to produce an image of the moon at that date showing the phase of the moon.

I can't see anything in the photo that relates to illness. Perhaps there is something on the other side of the device ?

No, I'm pretty sure this is -exactly- what is used by the CDC.