~ Durch Kunst und Fleiss ~
This appears to be an old folk proverb from the Schwarzwald (Black Forest). The scene shows a musician playing with skill for a drink and a meal. The etched stein was designed by Fritz Quidenus and marked with the Mettlach logo and form number 3144, ca. 1900.
Durch Kunst und Fleiss
kommt Nutz und Preis.
Der's kann und Weiss
hat Trank und Speis.
Through art and diligence
comes utility and reward.
He who has skill and knowledge
has drink and nourishment.
Translation: Roy De Selms
Photo credit: Unknown