I'm fascinated by the design of the rocket stove and its simple-yet-amazing ability to dramatically increase the yield of heat from wood while conversely decreasing pollution. But the stoves I've seen require at least some amount of manufactured materials, which makes them difficult or impossible to create in the wild. So I'm wondering if there's some way to make a crude but effective rocket stove using only materials you'd be likely to find most places on earth, such as mud, stone, wood, and plant fiber. This clearly wouldn't be a long-term item, but something that could be made in a couple of hours that would last for a couple of weeks would be well worth the effort (especially if wood was scarce). But I'm a bit fuzzy on the specifics of how a rocket stove works, so I'm not sure how to approach the design. Does anyone have any thoughts? Thanks!