Vriesea,
The optimum ratio of weaponsmiths to copper mines is exactly 1.7:1, the highest ratio for fixed-production raw materials. Of course, the ratio can sometimes be higher for papyrus makers to reed gatherers and for brewers to barley meadow farms, and perhaps for chariot makers to wood gatherers.
Actarus_,
The production of a barley farm depends on fertility, whether it's a meadow farm, and (for a floodplain farm) how quickly it gets a laborer, so the optimum ratio of breweries to barley farms varies.
There are several other possible explanations for a surplus of clay, including: potters aren't fully staffed (as Vriesea mentioned), potters deliver too far, storage yards won't accept pottery, and storage yards aren't fully staffed. If you can't figure it out and aren't using Cleopatra, you could email a saved game (preferably zipped) with description to the address in my profile.
[This message has been edited by Brugle (edited 03-30-2001 @ 01:52 PM).]