A smaller sample of soil from each feature (everything that was in the bucket) is subjected to flotation. This process involves another contraption, made from an old metal barrel, in which charred plant remains are gently floated out of the soil with flowing water and caught in a fine screen. These tiny bits of charcoal, when properly identified, tell us which plants were grown as crops, which were gathered in the wild, and which kinds of wood were used for fuel.
