Surreal German Clock

This looks just a little like the famous melting clock, by Salvador Dali. The two halves of the face of the clock are at 90 degrees to each other. Yet somehow the hands manage to stay close to the face of the clock.

It is not immediately obvious how this happens, but if you pick the clock up and turn it upside down, all becomes clear. The hands of the clock are on hinges, which allows them to climb up one side of the clock face, and then descend down the other side. Ingenious!