Perched on a building corner overlooking a plaza in Hamburg, a small stone boy – part of the Hummel Fountain ensemble – projects from the façade. He cheekily presents his backside toward the city’s most famous local character, Johann Wilhelm Bentz, portrayed in a larger-than-life sandstone statue atop the fountain below. Behind him, a few grinning children complete the scene.

Bentz was a short-tempered 1800s water bearer who hauled fresh water through the overcrowded, impoverished streets of Hamburg before indoor plumbing. Locals knew him as “Hummel.” He was often taunted by neighborhood children, who reportedly chose their moment well, jeering while he trudged along with a heavy water yoke across his shoulders, unable to give chase. Some accounts add that they punctuated their taunts by baring their backsides.…