I built a turbine powered by convection to see if it would be a viable source of motive force in a primitive setting. In the past, I've used water power to power a hammer and a forge blower but I envisioned a method of producing power that would be independent of a water source. The concept of a "convection mill" that could be set up anywhere and powered by fire was what I wanted to test. So I modified an existing radial fan from my blower, giving it an axial form by twisting the blades. The design worked as a windmill when sat on tree forks so that the axle could spin freely. Next I tied it to a string and hung it above a fire whereby it spun about its vertical axis. I next tested it in a wooden frame above a fire where it spun well too. I then built a pyramidal hood to funnel the hot air up to the blades causing the fan to spin more efficiently. Finally, I used the turbine to power a forge blower. It did so very weakly and then the whole contraption burnt down.