Abstract
THE FRENCH WIRELESS TIME-SIGNALS.—These signals are now so widely used by astronomers for time-determination that it is well to direct attention to an alteration which is announced in Circulaire No. 4, Bureau Internationale de l'Heure. The signals have hitherto been sent out at definite mean times; but the time is determined by meridian transits of block-stars, which necessitates the use of a sidereal clock, the error of which must be determined, and that of the mean-time clock inferred by comparison. It is now announced that, in order to avoid this transformation, beats 1 and 300 of the rhythmic signals will be sent according to Greenwich sidereal time, and the interval between the beats will be 49/50 of a sidereal second (roughly 44/45 of a mean second, instead of 49/50 as formerly).
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Our Astronomical Column. Nature 108, 351 (1921). https://doi.org/10.1038/108351a0
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DOI: https://doi.org/10.1038/108351a0