Old clock, new clock, old numbers, new numbers.. I wonder how many kids there are now that know what roman numerals are, is it still taught today. In case any young ones on here don't know this, the top clock is a wind up clock. Wind up for time is broken, the wind up for the hour chime still works. And the lower clock is called a perpetual motion clock. It does not have any source of power out side of itself. It works on a balance principle. the wheel right under the clock face spins in one direction for a few seconds, then in the other direction it continually spins changing directions. Thus (perpetual motion) never stopping except to change direction. It will not stop unless shut off manually. Of course now days we have digital which are even newer than these two, but they need batteries, or solar to make them work. So I guess you could call these (green), no disposable power source
