Aquila Children's Magazine AQUILA Magazine Best Bits | Page 25

Wherever possible Vikings used the
position of the Sun and stars to navigate,
taking advantage of the longer periods
of daylight available in northern waters.
Some evidence has been found that
adapted sundials known as ‘bearing
dials’ or ‘sea compasses’ with markings
scratched on them were put to good
use, while other mariners also carried a
sunstone.
On overcast days Vikings used sunstones
to locate the Sun so they could plot their
position.
Atmosphere polarises
light in circular pattern
Sun hidden
behind clouds
Illustration: Robbie
A sunstone is a type of transparent
calcite crystal, also known as Iceland
spar. This stone has the ability to
polarise light, filtering it along different
axis.
Direction of light
polarisation in crystal
matches polarisation of
the sunlight
Navigator points
sunstone at a patch of
sky and twists it until it
appears brightest. The crystal
now points
toward the Sun
Navigator
repeats the
process for
another patch
of sky. The
intersection
of the two
readings
reveals the
Sun’s location