collimatorn.
/ˈkɒlɪmeɪtə/ 1. A small fixed telescope with cross-wires at its focus, used for adjusting the line of collimation of an astronomical or other instrument.
ΘΚΠ
the world > physical sensation > sight and vision > optical instruments > instrument for distant vision > [noun] > telescope > other telescopes
polemoscope1668
finder1738
night-glass1758
collimator1825
floating collimator1833
lookdown1865
guiding telescope1897
autocollimator1903
kinetheodolite1941
finderscope1946
satellite telescope1951
scotoscope1964
starlight scope1964
1825 H. Kater in Philos. Trans. (Royal Soc.) 115 147 (title) Description of a floating Collimator.
1843 Rep. Brit. Assoc. 12 Two fixed collimators, watched by levels..enable the observer to determine the position..of the horizontal line.
1885 C. S. Murray in Brit. Almanac Compan. 120 A collimator..is a telescope furnished with a micrometer at its focus.
1890 Athenæum 19 Apr. 494/2 Col. Davidson devised [c1855] a collimator for night firing with artillery at a siege.
2. The tube with a slit and lens (or the lens itself) used in the spectroscope to collect the light and throw it upon the prism in parallel rays.
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the world > physical sensation > sight and vision > optical instruments > instruments for observing > [noun] > light or radiation > parts of
collimator1865
1865 Intellectual Observer No. 36. 389 One-half the slit of the collimator.
1887 Encycl. Brit. XXII. 373 The spectroscope..consists of three parts, the collimator, the prism or grating and the telescope..The most important adjustment in the spectroscope is that of the collimator.
This entry has not yet been fully updated (first published 1891; most recently modified version published online September 2018).
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n.1825