No groping in the dark
How did people in former times tell the time at night? This reconstruction of the stardial invented about 500 years ago makes use of the fact that the constellation Plow / Big Dipper orbits the North Star Polaris once in 23 hours and 56 minutes, as if it was the hand of a giant clock. Because of the difference of 4 minutes compared to a whole day, the sidereal clock is set to the current date before reading, then it shows the True Local Time with amazing accuracy. You can even feel it with your fingertips in the dark.
On the back of the Stardial is a sailor's astrolabe for determining the altitude of the Sun, stars, and landmarks.
How it works
Turn the date disc until the current date is in the read-out window of the handle above the arrow mark. Find the constellation Plow / Big Dipper and from there the North Star. Hold the stardial by the handle so that it points vertically downwards and, with your arm half bent, take a bearing on Polaris through the hole in the axle. Turn the star pointer until its straight edge is parallel to the two rear stars of the Plow. The Plow on the stardial is now positioned like the one in the sky. Read the True Local Time from the read-out window of the stardial or by counting the long and short spikes of the hour disc with your fingers.
This kit contains:
- 4 pre-cut sheets of A4 construction cardboard (2 printed, 2 blank)
- detailed construction manual
Features: easy to read by touch in the dark
Dimensions of the built item: approx. 21 x 23 cm
Construction time: approx. 4 hours
Producer: AstroMedia GmbH, Im Wirrigen 30, 45731 Waltrop, Germany, astromedia.de
Below you can download the instructions for this kit.
Further information:
Things you will need for assembly:
- a firm and flat working surface, useful is a cutting mat
- a sharp craft knife or a scalpel
- some fine sandpaper
- a good universal glue
Supervision by adults:
Children under the age of 14 should only use the kit under adult supervision to avoid risks due to improper handling.
Risk of injury:
Take particular care when handling pointed and sharp parts! Use sharp tools with care and take appropriate safety measures to avoid injury.
Fire hazard:
Keep away from open sources of fire and heat. Model is made of highly flammable materials.
Use of adhesive:
When using adhesive, follow the manufacturer's safety instructions. Work in well-ventilated areas and avoid contact with skin or eyes.
Intended use:
The kit should be used in accordance with the enclosed instructions. Independent modifications may impair the functionality and safety of the model built.
