I suspect it's something to do with the weight of each end changing as the wax drips of.
As it drips off one end, the weight reduces tipping the balance and that jolt causes the other end to drip, ad infinitum.
OR SUMTIN.
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Fork Has lost his bash virginity!, Sat 12 Jan 2013, 12:05,
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^this
It's acting as a mass balance. You can see the amplitude of oscillation jump as the wax drips off the low end. This loss of mass moves the centre of mass above the pivot and therefore accelerating the rotation. The oscillation then decays away before the next drip.
Level balance is maintained as the heavier end will be lower on average, therefore experiencing a higher melting rate.
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wheresthefish Partly filled with wrong, Sat 12 Jan 2013, 12:56,
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