[time-nuts] Re: Derivation of time from celestial sight

[David Taylor]

On 27/12/2021 20:18, Brent wrote:
> My understanding (and I could be wrong) is that one could derive 'stellar'
> time from a start sight/fix on polaris or another well tracked celestial
> object.  I was once told that early editions of Bowditch provided the
> process (for the moon I was told) although one of the relatively old
> edition's that I have doesn't provide it.
> 
> Some theodolite manufacturers provided attachments to aid the process (for
> the high zenith where a theodolite experiences reduced accuracy), and those
> attachments were dated and calibrated for their year of manufacture and
> came with tables for use in future years.
> 
> That's about all I know or can find on the subject.  Can anyone here point
> me to any published literature?  Anyone have experience trying?  Any idea
> what type of accuracy can be expected?
> 
> Got some new toys coming and need something to do with them....
> 
> Brent

Brent,

You might find something like these of interest:

   http://www.thegreenwichmeridian.org/tgm/articles.php?article=6

   https://www.rmg.co.uk/stories/topics/airys-transit-circle-dawn-universal-day

   http://www.royalobservatorygreenwich.org/articles.php?article=1087

There is a possibly apocryphal tale that some students at Cambridge did this in 
the late '60s or early '70s and getting about a second or two accuracy, and 
discovering that the longitude of the Cambridge Observatory was some hundred 
metres out.  You might find a reference, and I might be mistaken!

Cheers,
David
-- 
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