Astrolabe

The astrolabe or 'star-taker' was, and is, a remarkably elegant analogue computer. It could be used to provide a working model of the universe, measuring the heavens into a two-dimensional form. It mapped the heavens, allowing accurate predictions of when and where stars would appear in the sky. It was a star chart, and an aid in all kinds of navigational and calendrical calculations. An example from a master craftsman could also be an extremely beautiful and expensive object.