Another historical item I found intriguing was a trig. table from China,
printed several centuries ago. It showed several decimal places, and, of
necessity, did have zeroes as required. Fairly sure they were simple
circles of constant stroke width; nothing at all sophisticated. It is an
image in a book, translated from German, iirc, published ~25 years ago;
by Karl Menninger (Not Karl A.) about the history of numbers.

Regards,

--
Nicholas Bodley /*|*\ Waltham, Mass.
The curious hermit -- autodidact and polymath
Freedom from hypocrisy is a very good idea.
skimming e-mail -- near-perpetual overload...