The fourth clockwork is constructed from twelve clocks. The long hands of the clocks point against the short hands of the next clock. The clocks work, faster than real time though. The high speed shows the movement.
In the first variation the clocks works synchronously, in the others they are late a certain time.
As one of the results of the french revolution in Europe (at least in countries with a some common sense) we use decimal unit system. Do you have an idea why angles and time is an exception?
The decimal number system is simply not magical enough to measure time. Or anything else what is connected to circles.