[time-nuts] Greenwich time ball

asmagal at fc.up.pt asmagal at fc.up.pt
Sun Nov 7 23:02:00 UTC 2010


Quoting Bob Marinelli <bobm at stanford.edu>:

>
> I guess this is the time to propose that, if possible, every Time Nut
> needs to visit Greenwich Observatory at least once :)
>
> -Bob
>
Returning today from London where, incidentlly, I had the opportunity
to visist the Royal Observatory, I hope to have fulfilled my "religious
duties" of the Meca pilgrimage.

Let me say that I mostly did aprecite the Harrison´s clocks and the
Airy's Meridian Transit Circle.

One of the major problems of the conventional MTC instruments are
the errors due to flexion of the telescope. To remove at least this
difficulty the British astronomer R. d'E. Atkinson proposed in 1946
a new  instrument where a flat tilting mirror between two horizontal
fixed telescopes lying in the plane of the meridian, one at South
and another at Nort, could observe any object on its superior
culmination. This instrument is the rare (only three were ever built
in the world) Mirror Meridian Transit Circle.
Besides that at the Pulkovo Observatory, the only other which saw the
first light is until today at the Astronomical Observatory of the
University of Porto in Portugal.

(English is not my mother tongue: please be indulgent...)

Best regards,
Antonio
CT1TE




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