Sure, it doesn’t look like a computer. But back in the 11th and 12th centuries, this analog device would have been pretty new-fangled to budding astronomers and navigators. Known as a Volvelle, this rotating paper chart was used to calculate the position of the sun (Solis) and moon (Luna) at different points throughout the year. A circle with letters in red also indicates the astrological sign associated with each period.

Introduced to Europe in 1274 by artist, mystic philosopher and crazy-moustache-haver Ramón Llull, the design of the Volvelle was based on astrolabes - thin engraved metal discs used for the same purpose. The use of astrolabes was quite expensive, and paper-based versions were introduced as a cheaper alternative.