Ah foundries!

I few years ago I looked into the research value of mid-19th-century iron
foundries for a research design that I was working on. Phoned a bunch of
people, delved into reports, etc. I even ended up taking a three-day
hands-on class at an historic foundry in which I learned green sand
molding, cupola firing, and iron pouring. I can now distinguish furnace
slag from cupola slag from blacksmith slag (now that's esoteric).  It was
great fun but it didn't get me any closer to a satisfactory answer as to
why it might be worthwhile digging a foundry of this period. 

What I'm getting at is this. If you know that there was an industrial
foundry there and have an idea of its layout, what are you going to learn
from digging it that you didn't already know? Will chemical analysis of the
waste tell you anything worthwhile? Not sure. Also, considering the
potential for toxic contamination on these sites, I'd be inclined to go
carefully.

Anyone out there in HISTARCH land got any ideas? 

Adrian Praetzellis
Sonoma State University