The steeple ball (also tower ball from German: Turmkugel) is a closed, typically rounded, capsule on the finial of many buildings in the German-speaking countries. A steeple ball is highly visible and hard to reach for repairs, so attention is paid to the quality of design, construction, and materials. The combination of durability and inaccessibility makes the steeple ball attractive for use as a time capsule. When roofs are renovated or renewed, new items (most often newspapers or coins) are added to the exisiting ones.[1]
Shiny and visible from many places in the city, capsules are also used as target points during geodetic surveying.[2]
Installing the steeple ball is one of the final steps in building or renovating a church roof. This event is often celebrated with a so-called Kugelfest.[3]