Geography: two rotating discs (volvelles) showing the times at different places compared to London, and the constellations visible in the sky at different dates and times, fixed to a card giving details of their use, and dimensions of rivers and mountains. Coloured engraving.

Licence: Public Domain Mark

Credit: Geography: two rotating discs (volvelles) showing the times at different places compared to London, and the constellations visible in the sky at different dates and times, fixed to a card giving details of their use, and dimensions of rivers and mountains. Coloured engraving. Source: Wellcome Collection.