2. Of or pertaining to a pedal; having pedals.
{Pedal curve} or {surface} (Geom.), the curve or surface
which is the locus of the feet of perpendiculars let fall
from a fixed point upon the straight lines tangent to a
given curve, or upon the planes tangent to a given
surface.
{Pedal note} (Mus.), the note which is held or sustained
through an organ point. See {Organ point}, under {Organ}.
{Pedal organ} (Mus.), an organ which has pedals or a range of
keys moved by the feet; that portion of a full organ which
is played with the feet.
The bright surface of this ethereous mold. --Milton.
2. Hence, outward or external appearance.
Vain and weak understandings, which penetrate no
deeper than the surface. --V. Knox.
3. (Geom.) A magnitude that has length and breadth without
thickness; superficies; as, a plane surface; a spherical
surface.
4. (Fort.) That part of the side which is terminated by the
flank prolonged, and the angle of the nearest bastion.
--Stocqueler.
{Caustic surface}, {Heating surface}, etc. See under
{Caustic}, {Heating}, etc.
{Surface condensation}, {Surface condenser}. See under
{Condensation}, and {Condenser}.
{Surface gauge} (Mach.), an instrument consisting of a
standard having a flat base and carrying an adjustable
pointer, for gauging the evenness of a surface or its
height, or for marking a line parallel with a surface.
{Surface grub} (Zo["o]l.), the larva of the great yellow
underwing moth ({Triph[oe]na pronuba}). It is often
destructive to the roots of grasses and other plants.
{Surface plate} (Mach.), a plate having an accurately dressed
flat surface, used as a standard of flatness by which to
test other surfaces.
{Surface printing}, printing from a surface in relief, as
from type, in distinction from plate printing, in which
the ink is contained in engraved lines.
2. To work over the surface or soil of, as ground, in hunting
for gold.
2. Of or pertaining to the magnetic pole, or to the point to
which the magnetic needle is directed.
3. (Geom.) Pertaining to, reckoned from, or having a common
radiating point; as, polar co["o]rdinates.
{Polar axis}, that axis of an astronomical instrument, as an
equatorial, which is parallel to the earths axis.
{Polar bear} (Zo["o]l.), a large bear ({Ursus, or Thalarctos,
maritimus}) inhabiting the arctic regions. It sometimes
measures nearly nine feet in length and weighs 1,600
pounds. It is partially amphibious, very powerful, and the
most carnivorous of all the bears. The fur is white,
tinged with yellow. Called also {White bear}. See {Bear}.
{Polar body}, {cell}, or {globule} (Biol.), a minute cell
which separates by karyokinesis from the ovum during its
maturation. In the maturation of ordinary ova two polar
bodies are formed, but in parthogenetic ova only one. The
first polar body formed is usually larger than the second
one, and often divides into two after its separation from
the ovum. Each of the polar bodies removes maternal
chromatin from the ovum to make room for the chromatin of
the fertilizing spermatozo["o]n; but their functions are
not fully understood.
{Polar circles} (Astron. & Geog.), two circles, each at a
distance from a pole of the earth equal to the obliquity
of the ecliptic, or about 23[deg] 28', the northern called
the arctic circle, and the southern the antarctic circle.
{Polar clock}, a tube, containing a polarizing apparatus,
turning on an axis parallel to that of the earth, and
indicating the hour of the day on an hour circle, by being
turned toward the plane of maximum polarization of the
light of the sky, which is always 90[deg] from the sun.
{Polar co["o]rdinates}. See under 3d {Co["o]rdinate}.
{Polar dial}, a dial whose plane is parallel to a great
circle passing through the poles of the earth. --Math.
Dict.
{Polar distance}, the angular distance of any point on a
sphere from one of its poles, particularly of a heavenly
body from the north pole of the heavens.
{Polar equation of a line} or {surface}, an equation which
expresses the relation between the polar co["o]rdinates of
every point of the line or surface.
{Polar forces} (Physics), forces that are developed and act
in pairs, with opposite tendencies or properties in the
two elements, as magnetism, electricity, etc.
{Polar hare} (Zo["o]l.), a large hare of Arctic America
({Lepus arcticus}), which turns pure white in winter. It
is probably a variety of the common European hare ({L.
timidus}).
{Polar lights}, the aurora borealis or australis.
{Polar}, or {Polaric}, {opposition} or {contrast} (Logic), an
opposition or contrast made by the existence of two
opposite conceptions which are the extremes in a species,
as white and black in colors; hence, as great an
opposition or contrast as possible.
{Polar projection}. See under {Projection}.
{Polar spherical triangle} (Spherics), a spherical triangle
whose three angular points are poles of the sides of a
given triangle. See 4th {Pole}, 2.
{Polar whale} (Zo["o]l.), the right whale, or bowhead. See
{Whale}.
{Cylindrical lens}, a lens having one, or more than one,
cylindrical surface.
{Cylindric, or Cylindrical}, {surface} (Geom.), a surface
described by a straight line that moves according to any
law, but so as to be constantly parallel to a given line.
{Cylindrical vault}. (Arch.) See under {Vault}, n.