Ah, I see. That is a very good wondering, Faldage.
Here's something from the Net that implies that the serpentine wall is strong even though one-brick wide (completely dousing my original memory of the walls I saw, but didn't!):
"Unlike a straight wall design, which is laid with two brick widths for support, the serpentine wall is only one brick wide. The strength comes from the s-like curve. "The arc of the curve gives it its support," said Mr. Maloney as he pointed to the precision-made arcs. "I researched it and did the advance preparation last fall. It takes a bit of engineering."
http://www.acorn-online.com/home835d.htm...but I'll look and see whether there might be something to explain why we see the serpentine and also the straight edge brick wall... Perhaps the other one was already there? Or came later?
