[time-nuts] Pendulums & Atomic Clocks & Gravity

[Mike S]

At 07:49 PM 5/26/2007, Brooke Clarke wrote...
>Back in the 1800s clock makers found ways to temperature compensate 
>the
>pendulum such as putting a Mercury thermometer at the bottom, using 
>metals with
>dissimilar expansion coefficients (Harrison used steel and bronze (no 
>zinc
>then)) or materials with almost zero COE like Invar.
>
>The Dent clock at Greenwich in 1885 had an arenoid type compensator to 
>remove
>barometric pressure effects, later clocks were run in vacuum.

Does your clock (you only stated you were adjusting the bob on a 
pendulum clock) have either feature? The vast majority, I would hazard 
to say, don't.