-
the
amount
by
which
a
propagating
wave
is
bent
-
The
act
of
refracting,
or
the
state
of
being
refracted.
-
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.
-
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.
-
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.
-
The
change
of
direction
of
a
ray
of
light
in
passing
obliquely
from
one
medium
to
another
of
different
density.
-
The
act
of
refracting:
the
change
in
the
direction
of
a
ray
of
light,
heat,
etc.,
when
it
enters
a
different
medium.
-
The
change
of
direction
of
a
ray,
as
of
light
or
heat.
-
The
change
in
the
direction
of
a
ray
of
light
or
heat
as
it
passes
through
a
smooth
surface
into
a
medium
of
a
different
density.
Double
refraction,
the
refracting
of
light
in
two
directions.
Astronomical
refraction,
the
apparent
angular
elevation
of
the
celestial
bodies
above
their
true
places,
due
to
the
refracting
power
of
the
air.
Angle
of
refraction,
the
angle
made
by
a
ray
of
light
and
a
line
perpendicular
to
the
surface
of
the
medium
through
which
it
is
passing.
-
The
bending
of
a
ray
of
light
towards
the
perpendicular
when
it
passes
into
a
denser
medium,
as
from
air
into
water,
and
from
the
perpendicular
when
it
passes
into
a
rarer
medium,
as
from
water
into
air;
in
mech.,
the
incurvation
or
change
of
determination
in
the
body
moved;
in
astron.,
the
apparent
angular
elevation
of
celestial
bodies
above
their
true
places,
caused
by
the
refracting
power
of
the
atmosphere;
double
refraction,
the
refraction
of
light
in
two
directions,
and
consequent
production
of
two
distinct
images.
X
