Anitique lever-opertated mechanical dice

While obviously an old concept, this is new to me: mechanical dice. Within the stylish faux tortoiseshell box, a mechanism is concealed. By removing the lid you are presented with the faces of two die and a small lever. When the lever is pushed the the dice rotate on discs of some sort. The are stopped using the lever again. I assume it is spring-driven, but maybe the movement of the lever both powers and stops the spinning die wheels. I'm not sure what the advantage is over actual dice, other then being mechanically nifty. Perhaps it is bit more quiet than throwing real dice around. I suppose this was a very early form or automatic random number generator which might have had uses beyond gaming and gambling too.

Here's a link to the full ebay listing with additional pictures of the 19th century mechanical dice.

---