Away on the wind~
Magic.
There are too many toasters in my chimney!
Sounds like some sort of Aether Spring; you're just replacing mechanical potential energy with arcane potential energy. In that particular case however, the magic isn't merely dissipated as per the heat example, but is instead directly converted into arcane energy to power other clockwork devices.
Following that logic, one need only "recompress" the spring occasionally via the energy pooling you spoke of, resetting the spring to it's original, fully-charged state.
Whether the physical manifestation of the object as a literal "spring" is necessary or merely decorative to suit the setting is malleable, Though tying the physical and magical states of the "spring" to one another may have some merit. The physical state of the "spring" changing, such as the way a thermometer reacts to heat, may provide a visual shorthand in the setting to determine how spent the "spring" is and when it will need reset.
I second Cygan's suggestion, because quickly breezing over explanations that are doomed to break suspension of disbelief will avoid breaking the reader's suspension of disbelief. Magic is more handy than science in this regard since using the word science without including an explanation will bug people. I also doubt the mechanics of this machine to improve the story any, and that your time is better spent focusing on the impact this machine has on humanity (like for example, needing to make a human sacrifice every X years to keep it running).
edited 1st Feb '11 5:29:55 AM by colbertimposter
If this actually goes into World Building, then... oopsie ¯(°_0)/¯
In this universe, human beings all possess a limited amount of magic, about the same as the physical strength required to run about a mile as fast as one happens to be able to— like physical strength, magical powers can be "exercised" and the amount can vary even though it will hardly ever go beyond a certain limit. To compensate, the world runs on clockwork and magic. Magic is pooled into a device that uses it to keep the clockwork going. Physically winding it is only done in power-failure emergencies. The magic, much like heat, dissipates over time. Therefore, someone has to go in every once in a while and replenish the device's supply.
I have no idea exactly how this device does its job.
edited 30th Jan '11 1:32:39 PM by snowfoxofdeath
Warm hugs and morally questionable advice given here. Prosey Bitchfest