This was a quick and fun project. The astrolabe is an ancient navigation device invented by the Greeks and developed to a high degree by the Arabs. If you’re curious, there’s a lot of YouTube vids.
One side allows determination of angles, the equation of time, and a distance-finding scheme. The other side is a star finder that is built according to the user’s latitude, and a timepiece. Plans are available from Clayton Boyer.
UPDATE: Here’s a webpage with all things astrolabe, including a widget to generate a plate specific to your location.
