In the 16th century, Portugese mathematician Pedro Nunes made an enormous contribution to nautical navigation with the invention of his Altitude Sundial.  By suspending the ring from it's cord in the sunlight, sailors can read where the sunbeam hits the interior markings to determine their latitude.

This modern replica of the original is cast in solid bronze to resist corrosion in the salty, sea air.  A beautiful, and fully functional collectors piece for sailors, horologists, and lovers of sea lore.

Diameter: 40mm / Width: 21mm / Thickness: 4mm

Full instructional pamphlet is included.