Dear Mac,

> I would have wagered a small amount that I had seen
> a map showing average annual sunshine in Vermont to
> be less than 30% of possible sunshine.  However, I
> just found a NOAA map which appears to show mean 
> annual sunshine here as 51 - 55 percent.

That's pretty good by U.K. standards!

> ... my point remains that, since a sundial functions
> as a sundial only part of the time, it really ought
> to be a pleasant thing to look at when it's not working.

Yes, agreed 100%.

> Do you have an estimate for the percentage of working
> hours during a year for a sundial at your location?

That's an embarrassing question and I have had to look
up the answer.  It seems that in Cambridge, England, we
average about 1700 hours of sunshine a year.

If you take the year as being 8766 hours this means we
get sun about 19% of the year.  This is about 40% of
daylight hours.

As this list has been reminded in recent weeks, even
when the sun is shining there are many reasons why a
sundial might still be in shadow.  The sun might be
on the `wrong' side of the dial or blocked by trees,
buildings, hills or other items of horizon pollution.

I see, from Wikipedia that the maximum sunshine ever
recorded in the U.K. in a single month was 383.9 hours
at Eastbourne (East Sussex) in July 1911.  That is
almost 52% of the total hours in the month.

You are right.  We had better make our sundials good
to look at even when they are in the shade!

Best wishes

Frank

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