9/7/14 Sunday in Lebanon,PA (Hershey Campground-TT)
Mass ended around 11:30 am. The Cornwall Iron Furnace was not far from the church but opened at noon so we wandered around the outside awhile before we could begin the tour. ($7/senior, 65+) It started with a movie at 12:30 pm, so we studied the artifacts in an outer room first. Our tour guide was one of the best – she had a way of explaining that everyone could hear and follow, plus she’d ask about questions and let there be silence. Sure enough questions bubbled up often. That really made our experience all the more interesting. Boy did we learn a lot about Iron Furnaces!
This is the only surviving intact Charcoal Cold Blast Furnace in the Western Hemisphere. It was built in 1742 by Peter Grubb, a stone mason who’d been mining nearby. The 3 hills that contained this high iron content ore have been dug through 1972, thus are now a large lake. Mt. Gretna, nearby, is where they got the wood. It took an acre of trees to burn into charcoal that would feed the furnace in one day. Because it took a long time to build to hot enough and cool, it was only allowed to cool when the water in the stream that powered their water wheel froze or was too low. The water wheel was necessary to power the bellows that brought more oxygen to the fire since more oxygen was required to get the fire hot enough to melt the iron ore. It BLASTED the air into the furnace. Later Coleman used the innovation of a steam engine for power, thus he used the heat emanating from the furnace to power the steam engine and didn’t have to shut it down except for maintenance once in a while.
Peter named it Cornwall after his home in England. His sons ran it after he died but they fought a lot and eventually sold it to Robert Coleman who, along with his descendants, ran it until 1883 when anthracite coal made it obsolete. It was abandoned until 1932 when his great-granddaughter donated it to Pennsylvania. Around 1972 the Pennsylvania Historical & Museum Commission renovated it and began sharing it with the public.
This building was for storing the charcoal. Men would carry it up the roof through those ladders, then drop it down.
These images explain the process of the furnace. It threw in some artifacts for good measure. They even made the cannons and cannonballs for our Revolution.
The charcoal storage building is where they have the visitor center now. A walkway leads from it to the “Charge Path” in the next building. Here they’d have carts of charcoal on one side and wagons of iron ore on the other side, with a complement of limestone at the back, near the far window. They’d “charge” the furnace with a layer of 250 lbs. of charcoal, 450 lbs. of iron oar and 50 lbs. of limestone which attached to the impurities, helping to separate them from the iron. In the final image you’re looking down the hole into furnace, where men would dump their “charge”.
This is the wheel that would turn the gears to power the pistons, all run by the steam engine (2nd image). The old water paddle wheel used to be in this spot. The little mechanism in the corner of the room where the steam engine was would sent a signal (bell) to the man watching the steam engine. Our guide said that the men would try sounding it, not the children, so they cut the long wire that used to hang down to ring it.
At the bottom of the furnace we see where the molten iron and slag came out. The slag was directed to where the walkway is, to be broken and carted off by young apprentices when it had cooled. You can see where the iron was directed into either molds (crates set near the furnace) or a path to the furrows in the sand. The name pig iron, still used today, refers to how they were arranged – like piglets at their mom. The center row of iron was called the sow.
When the tour was over it was well past lunch time, so we headed home. We hope to visit again to check out the surrounding buildings they show in their brochure. We set out to WalMart for our groceries next. As soon as we got home I put together our Sassy Chicken Salad for the potluck, took a wee nap, then off we went to fun times with Randy/Sue (hosting the potluck), Susan, Gail/Larry. Only when it got really cold did we all head back to our homes.