geometry

I just realized that the canonical brick dimensions are
8 mm x 9.6 mm, *not* 5/16" x 3/8" as I had always assumed,
and furthermore, that it is possible to derive this fact
based on the existence of standard wheel diameters such as
43.2, 68.8, and 81.6. Has everyone else known this all along?
Steve Summit
snipped-for-privacy@eskimo.com