Also known as the 400-day clock because the clock would run for around 400 days on a single winding! This made it ideal for commemorating an anniversary because it could be wound once each year on the memorable date.
Other versions were rated at 1000 days per wind (which seems like over-kill to me!) These precision mechanisms are truly show pieces and are often enclosed in glass domes showing off their precision movements, polished brass, and complex escapement mechanisms (the rotating ball pendulum).
There are several german clock makers that are commonly encountered and their quality is generally excellent. Repairing these units is not for the amateur, however! They are finicky and require precise adjustment and watch cleaning equipment for the fine gears and pinions.
This specimen was acquired at an estate auction because it was broken and missing pieces. I haven't spent the time to restore it yet but hope to in the near future!