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    Re: Time balls
    From: Robin Stuart
    Date: 2019 Dec 20, 12:51 -0800

    Apparently not all time balls are spherical. This reference (in Spanish) https://archive.org/details/HistoriaDeLaAstronomiaArgentina/page/n307 describes the “time ball” in Buenos Aires from 1901 as being a canvas cylinder 2m in diameter by 2m in height and that it was dropped at 13:00 as defined by Argentina’s official meridian through Córdoba.  

    As explained on page 13 here this was probably what Captain Frank Worsley used on 24 October 1914 to rate the chronometers for Shackleton’s Imperial Trans-Antarctic Expedition before heading to South Georgia and on to Antarctica. We can be certain of the date because of the quote from the log recorded on page 86 here.

    Robin Stuart

       
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