They are built on tree stumps

In a letter to the AusChron about the way that long-standing businesses are being driven from South Congress (January 9, "Gentrification"), the writer mentions houses, as he puts it, built on foundations of tree stumps. It was very surprising to crawl under this house for the first time and see that the corner posts and all the piers on which the house rests are sections of cedar tree trunks with the bark still on (cedar-post piers). And then there's Orangeburg pipe.