The Nocturnal Dial

Given to Ben Huset by MAS on Feb 5th, 2002, as a token of appreciation.

(Click on any thumbnail to see a larger 640x480 JPEG image)

Instruction Book Cover
Instruction Graphic

Dial set for Feb 5th, 10:30pm
Night sky view at Feb 5, 2002 10:30pm via Starry Night
Back of Dial

Instruction Book Cover	Instruction Graphic
Dial set for Feb 5th, 10:30pm	Night sky view at Feb 5, 2002 10:30pm via Starry Night	Back of Dial

"Star" dials were first used in the 15th century by navigators who told time by the position of the stars. They work so well because they are based on the North Star, which is almost directly on the axis of the earth¹s tilt and always appears in the same position in the sky. All the other stars seem to revolve around it.

How to use

Set the spoke of the inner ring on the letter of the current month.
Hold the dial by the handle with the front facing you.
Sight the North Star (Polaris) through the center hole. Hold the Nocturnal close to your eye to sight Polaris, then extend your arm keeping the pole star centered in the hole.
Move the dial's arm to align with the UMa Alpha and UMa Beta, a.k.a. Dubbhe and Merak, the pointer stars of the Big Dipper in Ursa Major.
Read the time on the inner dial where the arm crosses the hour mark!

On the reverse side are outlines of the major constellations.

For more info see:

www.shepherdswatch.com

Available in the SMM giftshop.

Science Museum of MN
120 West Kellogg Blvd.
St. Paul, MN 55102
www.smm.org

Shot with Sony Mavica FD-7.

Photos by Ben Huset

Last revision Feb 6, 2002
by Ben
Counter started Feb 6, 2002-
Comments welcome