1790 portable compass sundial.
Fullsize image: https://s3-us-west-1.amazonaws.com/h...l_fullsize.jpg
Previously:
1570 Sundial ring - photo
3D-printed "digital" sundial - video
Multi-paneled sundial for time in different countries - photo
World's largest compass rose - GIF
ancient Chinese south-pointing chariot
Using an analog watch as a compass - photo
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