经纬仪
经纬仪
中星仪

[ noun ]
a telescope mounted on an axis running east and west and used to time the transit of a celestial body across the meridian
<noun.artifact>

Transit \Trans"it\, n. [L. transitus, from transire to go over:
cf. F. transit. See {Transient}.]
1. The act of passing; passage through or over.

In France you are now . . . in the transit from one
form of government to another. --Burke.

2. The act or process of causing to pass; conveyance; as, the
transit of goods through a country.

3. A line or route of passage or conveyance; as, the
Nicaragua transit. --E. G. Squier.

4. (Astron.)
(a) The passage of a heavenly body over the meridian of a
place, or through the field of a telescope.
(b) The passage of a smaller body across the disk of a
larger, as of Venus across the sun's disk, or of a
satellite or its shadow across the disk of its
primary.

5. An instrument resembling a theodolite, used by surveyors
and engineers; -- called also {transit compass}, and
{surveyor's transit}.

Note: The surveyor's transit differs from the theodolite in
having the horizontal axis attached directly to the
telescope which is not mounted in Y's and can be turned
completely over about the axis.

{Lower transit} (Astron.), the passage of a heavenly body
across that part of the meridian which is below the polar
axis.

{Surveyor's transit}. See {Transit}, 5, above.

{Transit circle} (Astron.), a transit instrument with a
graduated circle attached, used for observing the time of
transit and the declination at one observation. See
{Circle}, n., 3.

{Transit compass}. See {Transit}, 5, above.

{Transit duty}, a duty paid on goods that pass through a
country.

{Transit instrument}. (Astron.)
(a) A telescope mounted at right angles to a horizontal
axis, on which it revolves with its line of
collimation in the plane of the meridian, -- used in
connection with a clock for observing the time of
transit of a heavenly body over the meridian of a
place.
(b) (Surv.) A surveyor's transit. See {Transit}, 5, above.


{Transit trade} (Com.), the business conected with the
passage of goods through a country to their destination.


{Upper transit} (Astron.), the passage of a heavenly body
across that part of the meridian which is above the polar
axis.