heliometern.
/hiːlɪˈɒmɪtə/ 1. An astronomical instrument originally devised for measuring the diameter of the sun; now much used in determining the angular distance between two stars. Also attributive.It consists of a telescope, having the object-glass divided into two parts, each of which can be made to slide past the other and thus superpose the two images produced.
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the world > the universe > cosmology > science of observation > astronomical instruments > distance between bodies > [noun]
heliometer1754
1754 J. Short in Philos. Trans. 1753 (Royal Soc.) 48 165 M. Bouguer had read..in the year 1748, a memoir, in which he describes an heliometer; which is an instrument, consisting of two objective glasses, for measuring the diameters of the planets.
1836 Penny Cycl. V. 269 An invention of his in 1748, which he calls the heliometer, and which is in fact the first double object glass micrometer, and was properly so called.
1874 Monthly Notices Royal Astron. Soc. XXXIV. 279 The planet Juno at the opposition of 1874 appears to be very favourably situated for a trial of this method..and the Repsold Heliometer, with which the transit is to be observed, a suitable instrument.
1893 R. S. Ball Story of Sun 334 The heliometer of six inches aperture at the Yale Observatory.
1893 D. Gill (title) Heliometer observations for determination of stellar parallax made at the Royal Observatory, Cape of Good Hope.
1905 Astrophysical Jrnl. 22 103 The heliometer measures made in connection with transits of Venus in 1874 and 1882.
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1875 in E. H. Knight Amer. Mech. Dict. II.
Derivatives
heliometry n. /hiːlɪˈɒmɪtrɪ/ the art or practice of using the heliometer.
/hiːlɪˈɒmɪtrɪ/ the art or practice of using the heliometer.This entry has not yet been fully updated (first published 1898; most recently modified version published online December 2021).
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n.1754