Desktop Celestial Tide Dial

If you can believe it, there was a time when humans did all kinds of complex computations without computers. This desktop gadget is a prime example. Available in two sizes, it’s a replica of a tidal abacus from 1570 that currently resides in a museum. It uses the moon to calculate the tidal cycles, and on the large model, the back side is a nocturnal dial that uses fixed stars to tell the time.

• Both dials are accurate, fully functional tools that don’t require an electrical outlet.
• Each size features a handsome Sapele mahogany base—all the more reason to display one on your desk or in your beach house.
• Comes with detailed specs about the use of the dial and its history.
• Made in Spain.