[time-nuts] Re: in-ground clock room

[Steve Allen]

On Wed 2021-09-08T18:54:03-0700 Tom Van Baak hath writ:
> I am considering a below ground "clock room" away from the house. This will
> be for some low-drift quartz oscillators and also a couple of precision
> pendulum clocks. The goal is long-term, unattended, and very undisturbed
> operation.

How deep?

Bulletin Horaire v3n46p262 (1929-02-10) reports the equipment,
facilities, and operations of Bureau International de l'Heure at
Observatoire de Paris.

The highest precision pendulum clocks, the ones which had mechanisms
to correct for temperature and pressure (the "garde-temps") were kept
27 m below ground in caves and galleries which were part of the
Paris catacombs.

Various issues of Bulletin Horaire report discontinuities in the
operation of those clocks due to distant earthquakes.

--
Steve Allen                    <sla at ucolick.org>              WGS-84 (GPS)
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