What is the substance that emits light in the watch? Is it radium?
It’s not radium; it’s some fluorescent substance that usually absorbs light when there is light and releases it when there is no light.
Radium cannot emit light; it can only emit radiation, which humans cannot see.
Supplement: When the fluorescent object has a light, it emits light but absorbs more and talks less. It releases and absorbs less when it is dark, so you can see the light it emits.
How long does it take to wind up?
Usually, about a month is enough because after the gears and parts of the mechanical watch are run in and lubricated, the energy consumed will be less, and the energy stored in daily wear is enough to maintain the regular operation.
Are the mirrors scratch-resistant?
Available friction is no problem, but the hardness of some artificial silicon carbide compounds can reach level 9. The same level will leave scratches on the mirror surface, such as artificial marble, minerals, and some artificial equipment, such as metals with silicon carbon added.
Why is the dry battery dead when I buy a watch that is not long?
The watch ran out of power only a short time after you bought it. Generally speaking, it is because the dry battery has been put in the eye when it leaves the factory and has started to consume power since then. When you bought it, it happened to be when it left the factory. It’s been a long time. Generally, in this case, the manufacturer will replace the dry battery for free.