Posted 3 years ago
rlwindle
(138 items)
I bought this clock on eBay, it is a massive French Onyx and Bronze Ormolu Crystal Regulator, What’s interesting is that this clock has a genuine mercury pendulum. The two silvery cylinders you see on the pendulum are actually glass vials, partially filled with mercury. Its purpose is to maintain accurate timekeeping despite temperature variations.
Metal expands when the temperature rises, so the pendulum will actually lengthen, causing the clock to run slower. However, the mercury in the vial rises upward with the elevated temperature. This causes the functional pendulum length to remain relatively stable, and the clock maintains more accurate time. Cooler weather has the opposite effect and will shorten the pendulum. Normally this would cause the clock to gain time, but the mercury level lowers, keeping “functional pendulum length” the same. Think of it as a remaining constant center of gravity.
This is one of the few clocks that ran straight out of the shipping box.
It is 18.5" in height, 12" inches in length, and 4.5 in depth, it has nibbles and fleabites on the onyx and one of the glass panels is broken, other wise it is in excellent running shape.
Quit a scientifically designed mechanism.
Beautiful!
Nice with good write up. Glass shouldn't be too expensive to replace ~$40-$50 at most. Thanks for sharing.