While the curiosity factor in an Atmos clock is purely cerebral (you may or may not be aware that there is something quite unusual and ingenious about the clock itself), Automaton clocks are visually very striking its mechanically driven figurines that dance or simply appear in windows: humans, animals, angels, mythical creatures, ships etc. These clocks are very expensive and no longer mass-produced, I believe. There are, however, some variations of the theme that you can still find, equally brilliantly performed. For example, the rotating clock shown here is a high quality mechanism that will make an excellent centerpiece in any modern home library.
It is debatable whether a clock is a desirable item at a home library. After all, library is a space where you may want to be free from the constraints of time. Things are a bit different if the clock you put on the shelf or on the desk is actually a curiosity of note. Being able to tell time would be an added feature, nothing more. Atmos clock is just such a curiosity. These clocks never have to be wound up. They simply use slight variations in atmospheric pressure, while actually keeping time in a very reliable way. Atmos clocks are Swiss-made! They can still be found at antique stores or you may be able to locate a clock by a different manufacturer.