> Looking at the examples shown on > <http://en.wikipedia.org/wiki/John_W._Nystrom>, it seems to me that > 0-8 are ordinary digits, and the symbols for 9 through 15 are inverted > or inverted+modified forms of the digits '7' through '1', so that > there is some sort of imperfect bilateral symmetry on the clock and > compass faces, with '0' and '8' as the axis of symmetry. Thus the '9' > is an inverted '6' (as 16-6=10) not an ordinary '9'. So except for the > odd glyph forms for 9, 11, 12 and 15 (would be be expected to be > simple inversions of '7', '5', '4' and '1') it makes sense as a system > to me.
Very good observation! /Sz
