In the dense Amazon rainforest, perched 20 meters above a branch, a brown capuchin monkey leisurely munched on wild fruit, unaware that this would be its last lunch. A sharp pain in its rump startled it, and instinctively it fled. As it ran, its limbs became increasingly unresponsive, until it could no longer even hold onto the branch and finally fell to the ground. Just then, an Indian, wielding a secret weapon, excitedly rushed over, picked up his trophy, and swaggered away.
Why were the monkeys perched so high in the branches so easily hunted? The answer lies in the Native Americans' "secret weapon"—the tube arrow. Why was the tube arrow so powerful? The Native American blowgun consisted of two parts: a blowpipe and a blowgun dart. The blowpipe was roughly a straight tube, thicker at one end and thinner at the other, while the blowgun was a long cone. To use it, the blowgun dart was loaded into the blowpipe, and the user blew forcefully towards the thicker end, propelling the dart at high speed in the direction the blowpipe was pointing and striking the target. You might be wondering: would a capuchin monkey fall down after just one prick from a blowgun dart? Actually, the Native Americans used a biological toxin discovered in the Amazon rainforest and coated it onto the blowgun. This toxin quickly paralyzed the prey, thus eliminating any chance of escape for the struck capuchin monkey.
Have you ever wondered why you blow on the thicker end of the blowgun? Would it work if you blew it the other way around? Well, we need to look at what happens during the launch of the blowgun.
When a person blows air into a blowpipe, the air rushes from the larger end to the smaller end. To maintain a consistent flow rate at both ends, the air must travel faster at the smaller end. This effectively accelerates the air, propelling the blowgun inside at high speed. Blowing in the opposite direction produces the opposite effect.