(This research agrees with what various Yup'ik hunters
said they were told by their elders.)

by ED GERSTNER

23 April 2003

Dart thrower caught on camera
High-speed video reveals dynamics of ancient weapon.

Atlatls help propel darts at more than 100 kilometers an hour.
The atlatl - pronounced "at-la-tal" - is a hand-held
spear-thrower that was developed in northern Africa 25,000 years ago.
Now high-speed video imaging of modern-day atlatl throws could help
to settle archeologists' debates about the design and construction of
the simple but effective gadgets. Atlatls spread all over the world before
being largely superceded, around 10,000 years ago, by the bow and arrow.
The atlatl's springy lever action flings flexible, lightweight darts at speeds
of more than 100 kilometres per hour over distances of more than 200 metres.

From digitized footage of atlatl throws, Californian electronics researcher
and primitive-technology enthusiast Richard Baugh, has developed a
computer model of the weapon's performance1. By varying its parameters,
such as the mass and flexibility of the atlatl or dart, Baugh can explore the
effects of these specifications on throwing speed.

Atlatls look rather like huge crochet hooks. They have a wooden
shaft 30-100 centimetres long, with a handgrip at one end and a
spur at the other into which a dart slots before being shot out with
a flick of the wrist. The weapon works on the same principle as the
gizmos sold in pet stores to help dog owners throw tennis balls. A
few atlatls have a curious weight, called a banner stone, mounted
halfway up the shaft.

Some archeologists argue that these stones were counterweights to
increase throwing performance - others believe that they were merely
decorative. Baugh's model suggests that increasing an atlatl's weight has
little effect on the dart's speed - but increasing the shaft's flexibility can
increase speed by up to 15%. Baugh now hopes to refine his model with
more detailed video information to include the effect of subtle variations
in throwing technique on the trajectory of thrown darts. Atlatls are used to
this day by indigenous Alaskan and Australian hunters. "There has also
been a resurgence of interest among people who are trying to relearn the
skills of our Stone Age ancestors," says Baugh -the World Atlatl Association
holds regular tournaments throughout North America and Europe.

Ed Gerstner is the editor of the Physics and Materials Portals of the
journal Nature.
References 1. Baugh, R. Dynamics of spear throwing. American Journal of Physics, 74, 345 - 350, (2003). |Article| © Nature News Service / Macmillan Magazines Ltd 2003