OK, thanks guys, Seems an adze can be used both with the edge flat with the sharpening on the underside, (kind of like a plane) and also with the edge down and the sharpening up. With the edge down and a hammerstone used, I can see where it could be an effective scraper,or channeler. (I like that description) Digging out a channel of wood, or burnt wood, would be a perfect task for that tool. Depending on what was scraped, or dug, the edge need not be really sharp. There was probably a tool for that purpose too. Not all adze's were made out of flint, or granite, or a really hard stone. Most were, but sandstone could be used on softer material, and would be easier to sharpen.