How to use an astrolabe

A new video on Ted.com gives an introduction to how to use an astrolabe, an object that I've always wanted to have myself since I saw this picture on Wikipedia:

The video went up last month but I waited for a language to be added to the subtitles (in this case Spanish) before writing about it here.



Wikipedia has another image here showing what an astrolabe created with a computer would look like, although it likely wouldn't have all the other non-astronomical uses shown in the video.