I did some reading on Atmos timepieces. Fascinating and very brilliant thinking behind the design. In particular, it is the EC that makes it work. It has a very high thermal rate of expansion and even a one degree temperature change is enough to exert enough force on the spring to wind it to run a day. So even in a basement, all you would have to do is light a candle where the warmth would hit the bellows and change the temperature even a small amount. There have been other similar designs with mercury as the expansion agent (as I shall call it) but apparently the EC is superior. Whatever is used must exhibit the expansion/contraction properties at normal ambient temperatures. That's probably why EC works. I would not rule out another substance as a substitute, but research would be required. And it's not as though you would need to set the movement out in the sun to "wind" it. If it were sitting on a fireplace mantel, or a small table near a window, I'd think there would be more than enough differential over a period short enough to keep it running. Now I want one! lol I'll make a couple of phone calls tomorrow to some people I know to see if there is a way I can get my hands on some. Slim chance, but I won't know without asking.