Found 1 items, similar to Position micrometer.
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Definition: Position micrometer
Position
\Po*si"tion\, n. [F. position, L. positio, fr. ponere,
positum, to put, place; prob. for posino, fr. an old
preposition used only in comp. (akin to Gr. ?) + sinere to
leave, let, permit, place. See
Site, and cf.
Composite,
Compound, v.,
Depone,
Deposit,
Expound,
Impostor,
Opposite,
Propound,
Pose, v.,
Posit,
Post, n.]
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1. The state of being posited, or placed; the manner in which
anything is placed; attitude; condition; as, a firm, an
inclined, or an upright position.
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We have different prospects of the same thing,
according to our different positions to it. --Locke.
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2. The spot where a person or thing is placed or takes a
place; site; place; station; situation; as, the position
of man in creation; the fleet changed its position.
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3. Hence: The ground which any one takes in an argument or
controversy; the point of view from which any one proceeds
to a discussion; also, a principle laid down as the basis
of reasoning; a proposition; a thesis; as, to define one's
position; to appear in a false position.
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Let not the proof of any position depend on the
positions that follow, but always on those which go
before. --I. Watts.
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4. Relative place or standing; social or official rank; as, a
person of position; hence, office; post; as, to lose one's
position.
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5. (Arith.) A method of solving a problem by one or two
suppositions; -- called also the
rule of trial and error
.
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Angle of position (Astron.), the angle which any line (as
that joining two stars) makes with another fixed line,
specifically with a circle of declination.
Double position (Arith.), the method of solving problems by
proceeding with each of two assumed numbers, according to
the conditions of the problem, and by comparing the
difference of the results with those of the numbers,
deducing the correction to be applied to one of them to
obtain the true result.
Guns of position (Mil.), heavy fieldpieces, not designed
for quick movements.
Position finder (Mil.), a range finder. See under
Range.
Position micrometer, a micrometer applied to the tube of an
astronomical telescope for measuring angles of position in
the field of view.
Single position (Arith.), the method of solving problems,
in which the result obtained by operating with an assumed
number is to the true result as the number assumed is to
the number required.
Strategic position (Mil.), a position taken up by an army
or a large detachment of troops for the purpose of
checking or observing an opposing force.
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Syn: Situation; station; place; condition; attitude; posture;
proposition; assertion; thesis.
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Micrometer
\Mi*crom"e*ter\, n. [Micro- + -meter: cf. F.
microm[`e]tre.]
An instrument, used with a telescope or microscope, for
measuring minute distances, or the apparent diameters of
objects which subtend minute angles. The measurement given
directly is that of the image of the object formed at the
focus of the object glass.
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Circular micrometer, or
Ring micrometer, a metallic ring
fixed in the focus of the object glass of a telescope, and
used to determine differences of right ascension and
declination between stars by observations of the times at
which the stars cross the inner or outer periphery of the
ring.
Double image micrometer, a micrometer in which two images
of an object are formed in the field, usually by the two
halves of a bisected lens which are movable along their
line of section by a screw, and distances are determined
by the number of screw revolutions necessary to bring the
points to be measured into optical coincidence. When the
two images are formed by a bisected object glass, it is
called a divided-object-glass micrometer, and when the
instrument is large and equatorially mounted, it is known
as a heliometer.
Double refraction micrometer, a species of double image
micrometer, in which the two images are formed by the
double refraction of rock crystal.
Filar micrometer, or
Bifilar micrometer. See under
Bifilar.
Micrometer caliper or
Micrometer gauge (Mech.), a caliper
or gauge with a micrometer screw, for measuring dimensions
with great accuracy.
Micrometer head, the head of a micrometer screw.
Micrometer microscope, a compound microscope combined with
a filar micrometer, used chiefly for reading and
subdividing the divisions of large astronomical and
geodetical instruments.
Micrometer screw, a screw with a graduated head used in
some forms of micrometers; turning the head one full
revolution advances the position of the tip of the screw
only by a little.
Position micrometer. See under
Position.
Scale micrometer, or
Linear micrometer, a minute and very
delicately graduated scale of equal parts used in the
field of a telescope or microscope, for measuring
distances by direct comparison.
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