heliometer

American  

[hee-lee-om-i-ter] / ˌhi liˈɒm ɪ tər /

noun

1. a telescope with a divided, adjustable objective, formerly used to measure small angular distances, as those between celestial bodies.

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heliometer British  

/ ˌhiːlɪəʊˈmɛtrɪk, ˌhiːlɪˈɒmɪtə /

noun

1. a refracting telescope having a split objective lens that is used to determine very small angular distances between celestial bodies

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Other Word Forms

• heliometry
  noun
• heliometric
  adjective
• heliometrical
  adjective
• heliometrically
  adverb

Etymology

Origin of heliometer

First recorded in 1745–55; helio- + -meter

Example Sentences

See Examples For:

heliometer

Thus, for refined purposes, it cannot be assumed with any certainty that the instantaneous scale-value of the heliometer is known, or that it is a function of the temperature.

From Encyclopaedia Britannica, 11th Edition, Volume 13, Slice 2 "Hearing" to "Helmond" by Various

The present writer has successfully used a similar plan in measuring position angles of a Centauri with the heliometer, viz. by placing circular diaphragms on the two segments of the object-glass.

From Encyclopaedia Britannica, 11th Edition, Volume 13, Slice 2 "Hearing" to "Helmond" by Various

These two traditional methods were supplemented in 1874 by the camera and the heliometer.

From A Popular History of Astronomy During the Nineteenth Century Fourth Edition by Clerke, Agnes M. (Agnes Mary)

In 1877 Sir David Gill used Lord Crawford’s heliometer at the Island of Ascension to measure the parallax of Mars in opposition, and found the sun’s distance 93,080,000 miles.

From History of Astronomy by Forbes, George

A heliometer is the most accurate astronomical instrument for relative measurements of position, as a transit circle is the most accurate for absolute determinations.

From Pioneers of Science by Lodge, Oliver, Sir