Ng -
Astrolabes were tools used starting around 150 BC all
the way until just a few hundred years ago. They started off as one of
the first major 'multi-purpose' tools and were greatly improved during
the middle ages to be extremely versatile. The were basically flat
metal circles that could be hung from one edge like a pendant. The
metal had numerous inscriptions and could be used to calculate and/or
measure all these things:
the position of celestial objects
the time of the night (or day)
the time of the year
what part of the sky is visible at any time
the altitude of an object over the horizon
the current latitude
the NPS orientation
(from
Astrolabe History)
For
more information about the history of astrolabes, exactly how they
work, and how to build one yourself (including printable templates),
check out these links:
Astrolabes - This site from the University of Hawaii is really wonderful and has a lot of in-depth information.
The Astrolabe
- This site from the Stephen F. Austin State University has all the
really important details, condensed to be a bit shorter.
-Tamara
(published on 10/22/2007)
