Primitive Technology: Forge Blower

I invented the Bow Blower, a combination of the bow drill and forge blower to make a device that can force air into a fire while being easy to construct from commonly occurring natural materials using only primitive technology. I began by fanning a fire with a piece of bark to increase its temperature. It is this basic principle I improved on throughout the project. Next, I made a rotary fan from two pieces of bark that slot together at right angles to each other to form a simple 4 bladed paddle wheel about 20 cm in diameter and 5 cm tall. The blades of the fan were not angled and were designed only to throw air outwards away from the axle when spun. The rotor of the fan was made by splitting a stick two ways so it formed 4 prongs. The fan was then inserted into the prongs and the end lashed to hold it in place. Spinning the fan rotor back and forth between the palms of the hands fanned the fire. But only some of the wind generated by the fan reached the fire. The rest of it was blowing in other direction