The key to this mechanism is that the stepping of the minute hand is what unlocks the second hand. Pretty clever low-tech way to keep a LOT of clocks in really

The key to this mechanism is that the stepping of the minute hand is what unlocks the second hand. Pretty clever low-tech way to keep a LOT of clocks in really close sync. Dutch train stations used to have these too, I loved to watch them in action while waiting for a train.