zenith tube

noun

Astronomy.

1. a telescope mounted to point only at the zenith, used at some observatories for measuring time by the stars.

Word History and Origins

Origin of zenith tube¹

First recorded in 1830–40

Example Sentences

Congratulations, now you can crank up the ol’ hundred-pound Zenith tube and hear Curt Gowdy do the Oilers games.

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In 1848 Airy invented the reflex zenith tube to replace the zenith sector previously employed.

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He devised a reflex zenith tube, in which the zenith point was determined by reflection from a surface of mercury.

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The instrument is now being used for investigating these variations; and in the year 1907 as many as 1,545 observations of stars were made with the reflex zenith tube.

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In the Report to the Visitors there is an interesting account of the difficulties experienced with the Reflex Zenith Tube in consequence of the tremors of the quicksilver transmitted through the ground.

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