I was at Aetna and Cumberland furnaces today with Whipoorbill and a question came up.Why are they covered in dirt which someone went to great lengths to rmove at cumberland?I have found many ruins in the woods and most don"t seem to be nearl as covered over as these furnaces.They seem to be intentionally covered with dirt.Was it for insulation to hold in the heat?If not why?
Al
Al