Gregorian telescope

American  

noun

1. a telescope similar in design to the Cassegrainian telescope but less widely used.

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Gregorian telescope British  

noun

1. a form of reflecting astronomical telescope with a concave ellipsoidal secondary mirror and the eyepiece set behind the centre of the parabolic primary mirror

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Etymology

Origin of Gregorian telescope

1755–65; named after James Gregory; -ian

Example Sentences

But in the Gregorian telescope, the image formed by the principal mirror falls on a second mirror, which is very small, slightly curved, and parallel to the first.

From Project Gutenberg

Some recent discoveries in astronomy having arrested his mind, and awakened in him a powerful spirit of curiosity, he sought and obtained from a friend the loan of a two-foot Gregorian telescope. 

From Project Gutenberg