Aboriginal spear throwers
Spear throwers were often used with spears to increase the distance they could be thrown. The design of spear throwers depends on the people who made them. They are made out of hard wood and are usually 45 to 150 cm long. They have a peg at one end where the spear fits in and the thrower holds it by the other end to throw the spear. Using a spear thrower, an expert thrower can get two to three times the distance he could throw without using one. Spear throwers work according to the principle of levers, which are one kind of simple machine. There are three types of levers and a spear thrower is an example of the second type of lever. The peg is the fulcrum, the spear is the load and the effort is at the top of the spear thrower, provided by the thrower.
Some spear throwers could also be used to produce fire, by rubbing the edge against another softer piece of wood while keeping some kindling nearby.