Source : Webster's Revised Unabridged Dictionary (1913)
Dip \Dip\, n.
1. The action of dipping or plunging for a moment into a
liquid. ``The dip of oars in unison.'' --Glover.
2. Inclination downward; direction below a horizontal line;
slope; pitch.
3. A liquid, as a sauce or gravy, served at table with a
ladle or spoon. [Local, U.S.] --Bartlett.
4. A dipped candle. [Colloq.] --Marryat.
{Dip of the horizon} (Astron.), the angular depression of the
seen or visible horizon below the true or natural horizon;
the angle at the eye of an observer between a horizontal
line and a tangent drawn from the eye to the surface of
the ocean.
{Dip of the needle}, or {Magnetic dip}, the angle formed, in
a vertical plane, by a freely suspended magnetic needle,
or the line of magnetic force, with a horizontal line; --
called also {inclination}.
{Dip of a stratum} (Geol.), its greatest angle of inclination
to the horizon, or that of a line perpendicular to its
direction or strike; -- called also the {pitch}.
Horizon \Ho*ri"zon\, n. [F., fr. L. horizon, fr. Gr. ? (sc. ?)
the bounding line, horizon, fr. ? to bound, fr. ? boundary,
limit.]
1. The circle which bounds that part of the earth's surface
visible to a spectator from a given point; the apparent
junction of the earth and sky.
And when the morning sun shall raise his car Above
the border of this horizon. --Shak.
All the horizon round Invested with bright rays.
--Milton.
2. (Astron.)
(a) A plane passing through the eye of the spectator and
at right angles to the vertical at a given place; a
plane tangent to the earth's surface at that place;
called distinctively the sensible horizon.
(b) A plane parallel to the sensible horizon of a place,
and passing through the earth's center; -- called also
{rational or celestial horizon}.
(c) (Naut.) The unbroken line separating sky and water, as
seen by an eye at a given elevation, no land being
visible.
3. (Geol.) The epoch or time during which a deposit was made.
The strata all over the earth, which were formed at
the same time, are said to belong to the same
geological horizon. --Le Conte.
4. (Painting) The chief horizontal line in a picture of any
sort, which determines in the picture the height of the
eye of the spectator; in an extended landscape, the
representation of the natural horizon corresponds with
this line.
{Apparent horizon}. See under {Apparent}.
{Artificial horizon}, a level mirror, as the surface of
mercury in a shallow vessel, or a plane reflector adjusted
to the true level artificially; -- used chiefly with the
sextant for observing the double altitude of a celestial
body.
{Celestial horizon}. (Astron.) See def. 2, above.
{Dip of the horizon} (Astron.), the vertical angle between
the sensible horizon and a line to the visible horizon,
the latter always being below the former.
{Rational horizon}, and {Sensible horizon}. (Astron.) See
def. 2, above.
{Visible horizon}. See definitions 1 and 2, above.