>> Chronological years were invented around 500 AD, when people

sitll used Roman Numerals, which lack a symbol for zero.
Astronomical years were invented by Cassini in the 1700's,
when we had switched to the current number system, where there
is a symbol for zero. <<

I'm glad that the Romans didn't really have to go from -I to +I 'cos
that would have really messed up their abacuses :-)

Richard.


E-mail from: Richard Mallett, 23-Mar-2000