What does the picture illustrate?

The Kutna Hora prayer book, a remarkable work from the latter 15th century, has this illustration of silver-mining on its title page. Depicted in the lower third are the miners of Kutna Hora at work underground. The middle part shows treatment of the ore while the upper part presents division of the yield. Crowning the picture are the Emperor's symbols.

The aptness of the analogy with data-mining could hardly be clearer.

A larger image of the illustration