Nocturnal Celestial Stardials were originally called "horologium nocturnum" (time instrument for night), or nocturlabes. Sundials work great, but only during the day. Nocturnal Stardials tell time at night by measuring the stars. The dials move. It works like a charm. It needn't even be configured to longitude and latitude like a sundial.
This long-forgotten instrument aided a few lucky navigators and charmed romantics of the Renaissance. Earliest references include Cosmographicus Liber in 1530, Arte de Navegar, in 1551, and Horologiographia, The Art Of Dialling in 1626. 'Twas rare then as now.
The outer disc is marked with the months as well as an indicator for each of the 365 days of the year. The inner disc is marked with hours and 5-minute increments. The pointer rotates on the same center axis as the discs. The center axis has a sight hole through which the North Star Polaris can be aligned.
In the northern hemisphere, all stars will appear to rotate about the North Star, aka Polaris. The North Star is very close to the north celestial pole, but about 434 light years away.
The time can be read on my Nocturnal Stardial from any of three reference constellations: Big Dipper (Ursa Major), the Little Dipper (Ursa Minor), or Cassiopeia.
Recommended Materials and Processes:
ï· Computer with internet access
ï· 3d modeling software (or download my 3d model for free)
ï· access to 3d printer (I use Shapeways.com)