Bercow?? Please, no…

It gets the energy it needs to run from small temperature changes and atmospheric pressure changes in the environment, and can run for years without human intervention.

“

—	http://en.wikipedia.org/wiki/Atmos_clock

There is hopeful symbolism in the fact that flags do not wave in a vacuum

“

—	http://butdoesitfloat.com/26025

http://dvice.com/archives/2009/05/clock-clock-par.php