This article is not very good, notably, it is almost all guessing, no evidence.
An explanation that I would have found plausible: building stairs clockwise is cheaper somehow.
An explanation that I would have found plausible: building stairs clockwise is cheaper somehow.
Xe was a sports writer and art critic, not a historian, moreover.
It's a half-paragraph aside in a book entitled _Spirals in Nature and Art_, using words like "would" and "probable". And after 120 years of uncritical repetition and amplification, here we are.