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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
The use of the collimator with an altitude and azimuth instrument
From: Joel Jacobs
Date: 2004 Feb 3, 07:45 -0500
Observatory, Astronomical: Part I; 14 pages, 6 plates of illus. Price
2.00 {Item No.20414} [Includes: Introduction, Meridian instrument rooms: The
transit, The mural meridian circle, The transit circle, The repeating circle,
The equatorial, Portable observatories, Altitude and azimuth instrument,
Repeating circle (table)] [References part III of this article]
Observatory, Astronomical: Part II: On the proper manner of comparing
chronometers and other time-keepers; 9 pages Price 1.00 {Item No.20415}
[Includes: A.I. General rule, A.II. To compare a solar half seconds chronometer
with a sidereal clock, by coincidence of beats A.III. To compare a pocket
chronometer beating five times in two seconds, and going mean solar time nearly,
with a sidereal clock, by coincidence of beats. I. To adjust a portable transit
instrument, II. To determine the latitude by the transit, III. To determine the
latitude with the altitude and azimuth instrument, IV. To determine the sidereal
time in a place whose latitude is known, by observation with the altitude and
azimuth instrument, V. To determine the latitude and the sidereal time in a
place where neither of them is known, by observations with the altitude and
azimuth instrument, VI. Observation of equal altitude not recommended for use,
VII. General remarks on the rise of the sun instead of a star, in any of the
preceding observations]
Observatory, Astronomical: Part III: Observatory, Portable; 4 pages,
7 plates of illus. Price 2.00 {Item No.20416} [Construction plans for a portable
observatory]
Observatory, Astronomical: Part IV: Description of the Principle
Astronomical Instruments; 19 pages, 6 illus. Price 2.00 {Item No.20417}
[Includes: I. Hadley's sextant: To examine the error arising from the
imperfection of the dark glasses, To adjust the horizon glass, To examine if the
index glass be perpendicular to the plane of the instrument, To adjust the line
of collimation, To determine the index error, Note. 2. Troughton's reflecting
circle: Directions for observing with Troughton's reflecting circle. 3. The
Transit Instrument: To make the axis horizontal, To adjust the line of
collimation in azimuth, To adjust the transit to the meridian, Example, Method
of observing with the transit, Use of the portable transit. 4. The portable
Altitude and azimuth instruments: Introduction, Adjustments: Adjustments of the
vertical axis, Adjustment of the horizontal axis, Adjustment of the circle to
its reading microscopes, Adjustment of collimation in azimuth, Adjustment of
collimation to altitude, Use of the altitude and azimuth instrument. 5. The
Reading Microscope: Adjustments of the reading microscope. 6. The Collimator:
The use of the collimator with an altitude and azimuth instrument, Example]
Note. This entire section on 'Observatory, Astronomical' is
available: 44 pages, 6 figures and 14 plates of illus. Price 7.00 {Item
No.20418}
From: Joel Jacobs
Date: 2004 Feb 3, 07:45 -0500
FYI, Someone might find this interesting. It needs to be tracked to its
origin
