refractors

Unlike some other major brands of inexpensive refractors on alt-azimuth mounts, we're looking at good quality here… thrust-bearing surfaces well lubricated and teflon bearings… the control knobs work easily and mechanically perfect to allow you to set just the right amount of tension to make everything work with ease.

The Sky-Watcher AZ4 102 Refractor Telescope… How Sweet It is! | Universe Today

It took a bit of reading to discover what the trouble was – chromatic aberration, endemic to all such primitive refractors.

Roy J. Glauber - Autobiography

And to make that happen, you need to position mirrors, beam splitters, refractors, polarisers and god knows what else.

SLACKERJACK – Luck Charm Deluxe

Giant reflectors and refractors had been given and were in use in other parts of the world, but none so large or so important as this.

The Titan

There were two small refractors, and a complicated horizon - tal affair which Mackay said was a mirror-transit-what - ever that might be.

The Sands of Mars

When making use of the term "common telescope," I would like to be understood as referring to good refractors with object glasses not exceeding three or three and one-half inches in diameter.

Scientific American Supplement, No. 832, December 12, 1891

The making of three-inch objectives, achromatic and of short focus, wrought a revolution in telescopes and renewed the demand for refractors, though prices, as compared with those of the present day, were very great.

Scientific American Supplement, No. 832, December 12, 1891

We now purpose to go back to the ages when there were neither reflectors nor refractors in existence; and to travel beyond the bounds of ascertained fact into the regions of fiction, where abide the shades of superstition and the dreamy forms of myth.

Moon Lore

In light gathering power this instrument is in a class with the Lick and Yerkes refractors, and it is at least as effective in astronomical photography, the purpose for which it was designed.

The University of Michigan

So far as we now know, a good three-inch telescope, nay, a first-rate two inch one, will show far more than our great-grandfathers ever saw, or dreamed of seeing, with their refractors.

Scientific American Supplement, No. 832, December 12, 1891