"Mike Tullett" wrote in message
...
On Thu, 7 Aug 2003 16:46:05 +0100, Alastair McDonald in
wrote:
snip
I was looking for a sun spot cycle in the figures and noticed that all the
figures are 5 or less except 1995 and 1976 which are 19 years apart and
1893
and 1911 which are 18 years apart. I wonder if there is an 18.5 year
cycle
somewhere :-?

Lunar nodal cycle, Alastair :-)?

Well it repeats after 1976 - 1893 years. That's 83. So 83 must be the
lowest common multiplier of 18.5 and another cycle which is a multiple
of approx 4.5 years. So we are looking for another cycle of around
5, 9, 27, or possibly 83 years. Any ideas Mike?

Cheers, Alastair.