Can anyone help me with this chimney problem? | Melting Smelting | Forum

Today I walked past a house with this weird shed-outcrop building with a chimney-like thing on top. Now i'm not sure if this chimney was connected to the shed, but it was producing a lot of smoke. Either way, i began to get concerned that someone inside was melting some kind of hazardous metal or material, but the smoke only smelt of classic wood. For reference the 'chimney' looked more like a vase or a jug than a chimney, and appeared to have something underneath it, like an aluminum baking tray, but it still seemed like so much smoke couldn't come out of such a small thing. My question is, was it a chimney for smelting/melting or was it just some kind of strange fire pit? I just don't want to be breathing in hazardous fumes on my morning walk is all.