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2 definitions found
 for Positive eyepiece
From The Collaborative International Dictionary of English v.0.48 :

  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]

From The Collaborative International Dictionary of English v.0.48 :

  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.
        [1913 Webster]

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