Found 1 items, similar to Positive eyepiece.
English → English (gcide) Definition: Positive eyepiece Positive \Pos"i*tive\, a. [OE. positif, F. positif, L. positivus. See Position.] 1. Having a real position, existence, or energy; existing in fact; real; actual; -- opposed to negative. “Positive good.” --Bacon. [1913 Webster] 2. Derived from an object by itself; not dependent on changing circumstances or relations; absolute; -- opposed to relative; as, the idea of beauty is not positive, but depends on the different tastes individuals. [1913 Webster] 3. Definitely laid down; explicitly stated; clearly expressed; -- opposed to implied; as, a positive declaration or promise. [1913 Webster] Positive words, that he would not bear arms against King Edward's son. --Bacon. [1913 Webster] 4. Hence: Not admitting of any doubt, condition, qualification, or discretion; not dependent on circumstances or probabilities; not speculative; compelling assent or obedience; peremptory; indisputable; decisive; as, positive instructions; positive truth; positive proof. “'T is positive 'gainst all exceptions.” --Shak. [1913 Webster] 5. Prescribed by express enactment or institution; settled by arbitrary appointment; said of laws. [1913 Webster] In laws, that which is natural bindeth universally; that which is positive, not so. --Hooker. [1913 Webster] 6. Fully assured; confident; certain; sometimes, overconfident; dogmatic; overbearing; -- said of persons. [1913 Webster] Some positive, persisting fops we know, That, if once wrong, will needs be always. --Pope. [1913 Webster] 7. Having the power of direct action or influence; as, a positive voice in legislation. --Swift. [1913 Webster] 8. (Photog.) Corresponding with the original in respect to the position of lights and shades, instead of having the lights and shades reversed; as, a positive picture. [1913 Webster] 9. (Chem.) (a) Electro-positive. (b) Hence, basic; metallic; not acid; -- opposed to negative, and said of metals, bases, and basic radicals. [1913 Webster] 10. (Mach. & Mech.) (a) Designating, or pertaining to, a motion or device in which the movement derived from a driver, or the grip or hold of a restraining piece, is communicated through an unyielding intermediate piece or pieces; as, a claw clutch is a positive clutch, while a friction clutch is not. (b) Designating, or pertaining to, a device giving a to-and-fro motion; as, a positive dobby. [Webster 1913 Suppl.] 11. (Vehicles) Designating a method of steering or turning in which the steering wheels move so that they describe concentric arcs in making a turn, to insure freedom from side slip or harmful resistance. [Webster 1913 Suppl.] Positive crystals (Opt.), a doubly refracting crystal in which the index of refraction for the extraordinary ray is greater than for the ordinary ray, and the former is refracted nearer to the axis than the latter, as quartz and ice; -- opposed to negative crystal, or one in which this characteristic is reversed, as Iceland spar, tourmaline, etc. Positive degree (Gram.), that state of an adjective or adverb which denotes simple quality, without comparison or relation to increase or diminution; as, wise, noble. Positive electricity (Elec), the kind of electricity which is developed when glass is rubbed with silk, or which appears at that pole of a voltaic battery attached to the plate that is not attacked by the exciting liquid; -- formerly called vitreous electricity; -- opposed to negative electricity. Positive eyepiece. See under Eyepiece. Positive law. See Municipal law, under Law. Positive motion (Mach.), motion which is derived from a driver through unyielding intermediate pieces, or by direct contact, and not through elastic connections, nor by means of friction, gravity, etc.; definite motion. Positive philosophy. See Positivism. Positive pole. (a) (Elec.) The pole of a battery or pile which yields positive or vitreous electricity; -- opposed to negative pole. (b) (Magnetism) The north pole. [R.] Positive quantity (Alg.), an affirmative quantity, or one affected by the sign plus [+]. Positive rotation (Mech.), left-handed rotation. Positive sign (Math.), the sign [+] denoting plus, or more, or addition. [1913 Webster] eyepiece \eye"piece`\ eye-piece \eye"-piece`\, n. (Opt.) The lens, or combination of lenses, at the eye end of a microscope, telescope or other optical instrument, through which the image formed by the mirror or object glass is viewed. Syn: ocular. [1913 Webster] Collimating eyepiece. See under Collimate. Negative, or Huyghenian, eyepiece, an eyepiece consisting of two plano-convex lenses with their curved surfaces turned toward the object glass, and separated from each other by about half the sum of their focal distances, the image viewed by the eye being formed between the two lenses. it was devised by Huyghens, who applied it to the telescope. Campani applied it to the microscope, whence it is sometimes called Campani's eyepiece . Positive eyepiece, an eyepiece consisting of two plano-convex lenses placed with their curved surfaces toward each other, and separated by a distance somewhat less than the focal distance of the one nearest eye, the image of the object viewed being beyond both lenses; -- called also, from the name of the inventor, Ramsden's eyepiece . terrestrial, or Erecting eyepiece, an eyepiece used in telescopes for viewing terrestrial objects, consisting of three, or usually four, lenses, so arranged as to present the image of the object viewed in an erect position. 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