Stone Age KalashnikovNew Scientist
15 May 1999
By Kurt Kleiner
ROBERT PERKINS notches the long, flexible spear onto a spur on the end
of the stick in his hand. He draws back his arm, and throws. The spear
flies away from the stick, an atlatl, towards the hay bales 30 metres
away and thunks into the flattened cardboard beer carton that serves as
Never mind that a few of the missiles miss the target
and sail off into the Arizona desert beyond; everyone agrees that the
atlatl can be tricky to use. Besides, Perkins, a former competition
winner, has been so busy making and selling atlatls that he hasn't had
much time lately to practise. The reason he's so busy is that the
atlatl—a weapon that most hunters abandoned 10,000 years ago—is
enjoying a renaissance. Thousands of people in America and Europe are
making atlatls, competing in international tournaments, and even
hunting with them.
Perkins, or Atlatl Bob as he's known, is no
ordinary craftsman. Trained as an engineer, he is one of a group of
people who have been studying the mechanics of this primitive weapon
and found it to be surprisingly sophisticated. Using modern engineering
concepts and experimental techniques, they are rediscovering ancient
construction methods that make subtle but important improvements to the
Armour piercing"The physics and
math is all in here," Perkins says, weighing an atlatl in his hand at a
recent workshop on primitive technology held near Phoenix, Arizona. "It
really impresses me, the ability of these ancient people to be able to
do this. They certainly didn't have calculus. Wave mechanics, they
didn't know that. But they knew intuitively."
Atlatl is an Aztec
word for what's also called a throwing board or spear thrower. But most
enthusiasts object to the term "spear", since it suggests a rigid
shaft. An atlatl actually throws a flexible shaft that's more like a
150-centimetre-long arrow and is properly called a dart. The atlatl
itself is about 60 centimetres long, with a handle at one end and the
small, sharp spur at the other. A dart thrown with an atlatl can kill a
deer at 40 metres and will fly more than 200 metres. For comparison,
the world record for throwing the javelin is just
under 100 metres.
According to archaeological evidence, the
atlatl first made its appearance between 25,000 and 40,000 years ago in
the region that today encompasses Algeria, Morocco and Tunisia. From
here, it radiated outwards to Europe, Australia, Asia, and eventually
the New World. Then, about 15,000 years ago, the bow and arrow began to
displace the atlatl. The power and range of the two weapons are
comparable but the bow and arrow is easier to aim. The atlatl's
extravagant throwing action makes it more prone to wild shots, and can
startle the prey. Still, in some places atlatls survived until more
modern times. Aztec warriors greeted the invasion by Cortes in the 16th
century with atlatl darts capable of penetrating Spanish armour, and
Australian Aborigines still use them.
Today, many other people
are rediscovering the atlatl, thanks largely to the trend for
archaeologists to try to recreate the artefacts they find. Some modern
enthusiasts also seem to stumble across the atlatl for themselves.
"People call up and say, `I didn't know anyone knew about atlatls but
me. I've been making these since I was eight years old'," says Leni
Clubb, president of the World Atlatl Association, which is based in
Ocotillo, California, and sponsors contests and demonstrations.
discovered the atlatl while studying engineering at Montana State
University. He took a course in replicative archaeology and decided to
make it the focus of his study.
Perkins objects to the term "spear thrower" is that it gets in the way
of understanding how the atlatl really works. Some of the first
archaeologists to experiment with atlatls tried to throw rigid spears,
and managed only poorly aimed shots that flew just 45 metres. They
concluded that only constant practice from childhood would have allowed
anyone to use the weapon effectively. In fact, a beginner can start to
hit targets, large ones at least, after just an hour's practice.
how does the atlatl work? The thrower holds the atlatl and dart
parallel to one another and horizontal, with elbow bent and the hand
just beside the ear. There's an initial forward motion with the
shoulder, then the elbow straightens and finally the wrist flicks the
atlatl forward with an action not unlike that of an overexuberant fly
fisherman trying to lure a trout. The atlatl accelerates the rear of
the dart through an arc, with a movement similar to that of an ancient
ballista flinging boulders against the enemy.
That's the obvious
part. What isn't so obvious is how the projectile springs away from the
tip of the atlatl. In the early tests, the rigid spears were reluctant
to part company with the atlatl. So, all too often, at the end of the
throw, as the atlatl tip began to move downwards it would drag the back
end of the spear down too, ruining accuracy—an effect called kickdown.
(Some Inuits use atlatl-like sticks to launch rigid harpoons. But these
are launched downward from boats, and the kickdown effect doesn't make
A flexible dart, by comparison, springs away
from the atlatl tip. You can think of the dart as a spring, which is
compressed by the initial force of the throw. The dart releases this
stored energy at the end of the throw by pushing off the atlatl tip
before the tip begins moving downwards.
Perkins also analyses
the dart in terms of wave mechanics At the start of the throw, the dart
bends as the acceleration pushes against the mass of the stone tip. A
wave propagates from the rear of the dart to its tip. When the wave
reaches the tip, it is reflected back again. At the rear, the force
generated by the still-accelerating atlatl reinforces this wave and
sends it once more towards the dart tip, where it reflects again.
the wave reaches the rear this time, however, the atlatl has stopped
accelerating, and the wave's energy strikes the atlatl tip and propels
the dart forward. "The wave goes through a cycle of harmonic
oscillations, gaining a tremendous amount of energy as the dart's speed
is increased," Perkins explains. It's this energy, he argues, that
makes most of the difference between the 45 metres that a rigid spear
will travel and the 200-metre flight of a flexible dart.
energy is not stored just in the dart. Atlatls also bend, and release
their stored energy just as the dart launches. The atlatl's stored
energy is more modest in size than that stored in the dart, and can
probably account for increases in distance of about 10 per cent,
Looked at this way, the atlatl works very much
like a bow and arrow. When an archer draws back the bowstring, the bow
stores up energy which it releases very quickly to push the arrow
forward. "This is really the same weapon system as a bow and arrow,"
says Perkins. "It's a flexible shaft accelerator. The only difference
is that a bow is a linear accelerator. It's accelerating a flexible
shaft in a straight line. And the atlatl is doing it in an arc."
an ideal combination, the dart and atlatl have to be the right lengths,
with the atlatl about one third as long as the dart. They also need to
be made of the right stuff. Atlatls can be made from the same strong,
springy wood that bows are made from, says Perkins. He uses an American
hardwood called osage orange. Authentic darts he usually makes from red
osier dogwood, but if you want a modern dart he supplies them in
aluminium. The dart also has to be properly tuned. It must have the
proper amount of flexibility for its mass, and needs a mass at the tip
of the dart to aid compression. Perkins finds that a 7-gram stone point
optimises his 100-gram wooden darts.
Perkins also thinks he has
solved the mystery of atlatl weights—small, shaped stones which were
often attached to North American atlatls. One suggestion was that they
served a ritual purpose. But Perkins thinks the weights have a
function. Mounted about halfway down the rear of the atlatl shaft, the
weight helps to tune the flex of the atlatl. "The atlatl weight
improves the performance of the system in terms of efficiency," he
argues. "Smoother, more controlled and powerful launches make for
He also thinks a specific type of oddly shaped
weight, called a banner stone, served as a kind of silencer, stopping a
hunter's prey from being startled by the sound of the throw. Normally,
an atlatl makes a distinctive "zip" sound when the dart is thrown. But
a banner stone, extending sideways like wings on an aeroplane, again
about halfway down the atlatl, seems to muffle this sound. To test his
theory, Perkins threw a number of darts over the head of a very brave
engineer who measured the noise made by the launches. He found that,
sure enough, atlatls with a banner stone made less noise than those
But could primitive atlatl makers really have taken
advantage of all of these subtleties? Perkins believes they did. If the
atlatl weights and banner stones aren't convincing enough evidence,
there's also the mass of the stone points. For any dart, there is an
optimum weight for the stone tip, and the tolerance is fairly narrow.
day while at the Smithsonian Institution examining weapons left by
native Americans from North and South Dakota, Perkins found three stone
heads from the same site that had never been used. Two were made from
chert, the third from much denser flint. All were made in the same way,
but the one made of the denser stone was a centimetre shorter than the
others. They weighed 7.6, 7.7 and 7.8 grams. If the maker had designed
them by size alone, the denser point would have weighed much more.
Perkins argues that this shows the maker had a standard weight which
worked best with the darts.
Perkins hasn't proved his ideas, but
archaeologists take them seriously. "There's considerable difference of
opinion among professional archaeologists. Folks like Bob are doing a
real service by engaging in the actualistic research of these weapons,"
says Leslie B. Davis, an archaeologist and curator at the Museum of the
Rockies in Bozeman, Montana.
Others are more critical. Dick
Baugh, another engineer turned atlatl maker, published a paper in
Lithic Technology (Spring 1998) to counter the "extravagant claims
[that] have been made regarding the increased dart velocity achieved
with a flexible atlatl". Baugh created a computer model of a person
using an atlatl, then changed the length and flexibility of the atlatl
and removed the atlatl weights. He concludes that atlatl flexibility
makes little difference to performance, and atlatl weights make even
less. He also argues that while the dart's flexibility is important for
launching it off the atlatl, it makes little impact on the distance the
dart actually flies.
Ray Strischek of Athens, Ohio, who tied
last year for best shot in the world, thinks the flex in the atlatl
does make a difference. But rather than increasing velocity, he thinks
it acts as a sort of shock absorber, buffering the jerkiness of the
throw and creating a smoother, more accurate launch. "The debate goes
on," says Strischek. "No one has been able to quite pin it down."
a machine with a perfect throwing action reveals the importance of all
the various parameters, the experiments and controversy will continue
as people continue to be fascinated by the atlatl. "What separates us
from other predators is our ability to throw a projectile at a prey,"
says Perkins. "No other animal on Earth can do that. This is just our
supreme expression of using that natural ability."