Re*found", imp. & p. p. of Refind, v. t.
Re*found"er (-?r), n. One who refounds.
Re*fract" (r?*fr$kt"), v. t. [imp. & p. p. Refracted; p. pr. & vb. n.
Refracting.] [L. refractus, p. p. of refringere; pref. re- re- +
frangere to break: cf. F. réfracter. SEe FRacture, and cf. Refrain, n.]
1. To bend sharply and abruptly back; to break off.
2. To break the natural course of, as rays of light orr heat, when
passing from one transparent medium to another of different density; to
cause to deviate from a direct course by an action distinct from
reflection; as, a dense medium refrcts the rays of light as they pass
into it from a rare medium.
Re*fract"a*ble (-?*b'l), a. Capable of being refracted.
Re*fract"ed, a. 1. (Bot. & Zoöl.) Bent backward angularly, as if half-
broken; as, a refracted stem or leaf.
2. Turned from a direct course by refraction; as, refracted rays of
light.
Re*fract"ing, a. Serving or tending to refract; as, a refracting
medium.
Refracting angle of a prism (Opt.), the angle of a triangular prism
included between the two sides through which the refracted beam passes
in the decomposition of light. -- Refracting telescope. (Opt.) See
under Telescope.
Re*frac"tion (r?*fr?k"sh?n), n. [F. réfraction.] 1. The act of
refracting, or the state of being refracted.
2. The change in the direction of ray of light, heat, or the like, when
it enters obliquely a medium of a different density from that through
which it has previously moved.
Refraction out of the rarer medium into the denser, is made towards
the perpendicular.
Sir I. Newton.
3. (Astron.) (a) The change in the direction of a ray of light, and,
consequently, in the apparent position of a heavenly body from which it
emanates, arising from its passage through the earth's atmosphere; --
hence distinguished as atmospheric refraction, or astronomical
refraction. (b) The correction which is to be deducted from the
apparent altitude of a heavenly body on account of atmospheric
refraction, in order to obtain the true altitude.
Angle of refraction (Opt.), the angle which a refracted ray makes with
the perpendicular to the surface separating the two media traversed by
the ray. -- Conical refraction (Opt.), the refraction of a ray of light
into an infinite number of rays, forming a hollow cone. This occurs
when a ray of light is passed through crystals of some substances,
under certain circumstances. Conical refraction is of two kinds;
external conical refraction, in which the ray issues from the crystal
in the form of a cone, the vertex of which is at the point of
emergence; and internal conical refraction, in which the ray is changed
into the form of a cone on entering the crystal, from which it issues
in the form of a hollow cylinder. This singular phenomenon was first
discovered by Sir W. R. Hamilton by mathematical reasoning alone,
unaided by experiment. -- Differential refraction (Astron.), the change
of the apparent place of one object relative to a second object near
it, due to refraction; also, the correction required to be made to the
observed relative places of the two bodies. -- Double refraction
(Opt.), the refraction of light in two directions, which produces two
distinct images. The power of double refraction is possessed by all
crystals except those of the isometric system. A uniaxial crystal is
said to be optically positive (like quartz), or optically negative
(like calcite), or to have positive, or negative, double refraction,
according as the optic axis is the axis of least or greatest elasticity
for light; a biaxial crystal is similarly designated when the same
relation holds for the acute bisectrix. -- Index of refraction. See
under Index. -- Refraction circle (Opt.), an instrument provided with a
graduated circle for the measurement of refraction. -- Refraction of
latitude, longitude, declination, right ascension, etc., the change in
the apparent latitude, longitude, etc., of a heavenly body, due to the
effect of atmospheric refraction. -- Terrestrial refraction, the change
in the apparent altitude of a distant point on or near the earth's
surface, as the top of a mountain, arising from the passage of light
from it to the eye through atmospheric strata of varying density.
Re*fract"ive (r?*fr?kt"?v), a. [Cf. F. réfractif. See Refract.] Serving
or having power to refract, or turn from a direct course; pertaining to
refraction; as, refractive surfaces; refractive powers.
Refractive index. (Opt.) See Index of refraction, under Index. --
Absolute refractive index (Opt.), the index of refraction of a
substances when the ray passes into it from a vacuum. -- Relative
refractive index (of two media) (Opt.), the ratio of the sine of the
angle of incidence to the sine of the angle of refraction for a ray
passing out of one of the media into the other.
Re*fract"ive*ness, n. The quality or condition of being refractive.
Re`frac*tom"e*ter (r?`fr?k*t?m"?*t?r), n. [Refraction + -meter.] (Opt.)
A contrivance for exhibiting and measuring the refraction of light.
Re*fract"or (r&?;-fr&?;kt"&?;r), n. Anything that refracts;
specifically: (Opt.) A refracting telescope, in which the image to be
viewed is formed by the refraction of light in passing through a convex
lens.
Re*frac"to*ri*ly (r?*fr?k"t?*r?*l?), adv. In a refractory manner;
perversely; obstinately.
Re*frac"to*ri*ness, n. The quality or condition of being refractory.
Re*frac"to*ry (-r?), a. [L. refractorius, fr. refringere: cf. F.
refractaire. See Refract.] 1. Obstinate in disobedience; contumacious;
stubborn; unmanageable; as, a refractory child; a refractory beast.
Raging appetites that are Most disobedient and refractory.
Shak.
2. Resisting ordinary treatment; difficult of fusion, reduction, or the
like; -- said especially of metals and the like, which do not readily
yield to heat, or to the hammer; as, a refractory ore.
Syn. -- Perverse; contumacious; unruly; stubborn; obstinate;
unyielding; ungovernable; unmanageable.
Re*frac"to*ry, n. 1. A refractory person. Bp. Hall.