The Collaborative International Dictionary
Telescope \Tel"e*scope\, n. [Gr. ? viewing afar, farseeing; ? far, far off + ? a watcher, akin to ? to view: cf. F. t['e]lescope. See Telegraph, and -scope.] An optical instrument used in viewing distant objects, as the heavenly bodies.
Note: A telescope assists the eye chiefly in two ways; first, by enlarging the visual angle under which a distant object is seen, and thus magnifying that object; and, secondly, by collecting, and conveying to the eye, a larger beam of light than would enter the naked organ, thus rendering objects distinct and visible which would otherwise be indistinct and or invisible. Its essential parts are the object glass, or concave mirror, which collects the beam of light, and forms an image of the object, and the eyeglass, which is a microscope, by which the image is magnified.
Achromatic telescope. See under Achromatic.
Aplanatic telescope, a telescope having an aplanatic eyepiece.
Astronomical telescope, a telescope which has a simple eyepiece so constructed or used as not to reverse the image formed by the object glass, and consequently exhibits objects inverted, which is not a hindrance in astronomical observations.
Cassegrainian telescope, a reflecting telescope invented by Cassegrain, which differs from the Gregorian only in having the secondary speculum convex instead of concave, and placed nearer the large speculum. The Cassegrainian represents objects inverted; the Gregorian, in their natural position. The Melbourne telescope (see Illust. under Reflecting telescope, below) is a Cassegrainian telescope.
Dialytic telescope. See under Dialytic.
Equatorial telescope. See the Note under Equatorial.
Galilean telescope, a refracting telescope in which the eyeglass is a concave instead of a convex lens, as in the common opera glass. This was the construction originally adopted by Galileo, the inventor of the instrument. It exhibits the objects erect, that is, in their natural positions.
Gregorian telescope, a form of reflecting telescope. See under Gregorian.
Herschelian telescope, a reflecting telescope of the form invented by Sir William Herschel, in which only one speculum is employed, by means of which an image of the object is formed near one side of the open end of the tube, and to this the eyeglass is applied directly.
Newtonian telescope, a form of reflecting telescope. See under Newtonian.
Photographic telescope, a telescope specially constructed to make photographs of the heavenly bodies.
Prism telescope. See Teinoscope.
Reflecting telescope, a telescope in which the image is formed by a speculum or mirror (or usually by two speculums, a large one at the lower end of the telescope, and the smaller one near the open end) instead of an object glass. See Gregorian, Cassegrainian, Herschelian, & Newtonian, telescopes, above.
Refracting telescope, a telescope in which the image is formed by refraction through an object glass.
Telescope carp (Zo["o]l.), the telescope fish.
Telescope fish (Zo["o]l.), a monstrous variety of the goldfish having very protuberant eyes.
Telescope fly (Zo["o]l.), any two-winged fly of the genus Diopsis, native of Africa and Asia. The telescope flies are remarkable for having the eyes raised on very long stalks.
Telescope shell (Zo["o]l.), an elongated gastropod ( Cerithium telescopium) having numerous flattened whorls.
Telescope sight (Firearms), a slender telescope attached to the barrel, having cross wires in the eyepiece and used as a sight.
Terrestrial telescope, a telescope whose eyepiece has one or two lenses more than the astronomical, for the purpose of inverting the image, and exhibiting objects erect.
WordNet
n. any telescope designed to collect and record electromagnetic radiation from cosmic sources
Usage examples of "astronomical telescope".
When Galileo turned the first astronomical telescope to the sky, the tide began to turn.
A few books and instruments, and two months' victuals, was all the baggage he took with him, except an excellent astronomical telescope, which was, indeed, almost part and parcel of himself, and with which he assiduously scanned the heavens, in the sanguine anticipation of making some discovery which would immortalize his name.
The astronomical telescope's view showed the incoming missile pointing at them, more and more of a nose-on view as it sped to its target in the crater Alphonsus.
Within the dome an astronomical telescope gleamed dully, collecting dust.
It needed the precision of an astronomical telescope's lens, multiplied.
With the first astronomical telescope, however, Galileo was astonished and delighted to see Venus as a crescent lighted by the sun and to make out the mountains and craters of the moon.
Behind them, an antique astronomical telescope stood levelled at the horizon, gathering dust.
If Jelka used the astronomical telescope, she could probably see him standing there.