Ingenious Combination of two Sundials
Cut-out sheet for a double sundial following a design from the 19th century.
This special type of sundial was invented by the Greek astronomer Ptolemy (AD 100-160) and rediscovered in the 19th century by French clockmakers. They combined an analemnic sundial (featuring a date scale that accounts for the changing solar declination during a year) with a simple horizontal one. The vertical shadow thrower, or gnomon, is set to the correct date and the instrument is turned until both sundials show the same time. Now the sundial is facing exactly north, without the need of a compass. In the past this kind of sundial was produced for only for a given latitude. Further north or south they became more and more inaccurate. But that does not apply to the AstroMedia Compass Sundial:
Our sundial can be adjusted to all latitudes between 26° and 65°. The dial shows the time following two different methods, which enables you to find true north. You can read apparent local time (solar time) as well as "normal" time.
The Compass Sundial doesn't need a compass to orient it and can be adjusted to all latitudes between Oslo and Cairo.
This kit contains:
- 3 printed sheets to cut out of A4 construction cardboard
- detailed construction manual
Dimensions of the built model: approx. 17 x 13.5 x 15 cm
Construction time: approx. 2 hours
Producer: AstroMedia GmbH, Im Wirrigen 30, 45731 Waltrop, Germany, astromedia.de
Below you can download the instructions for this kit.
Things you will need for assembly:
- a craft knife or a scalpel
- a good pair of scissors, possibly also nail scissors for the curves
- a ruler
- a dull knife or a folding tool
- a good universal glue
Adult supervision:
Children under the age of 14 should 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 naked flames and heat sources. Product contains highly flammable materials.
Adhesive use:
When using adhesive, follow the manufacturer's safety instructions. Work in well-ventilated areas and avoid skin or eye contact.
