Hi Frank et al,
Dials with azimuth lines are rare but not unknown in the UK. Writing from
memory, there is a rather nice one on Grundisburgh church near me and I believe
the famous Queens' College, Cambridge, dial also has them amongst all the other
furniture. There are a few others, I'm sure: didn't Ian Butson restore a wooden
one?
The key requirement, of course, is that there has to be a nodus so the gnomon
on your lighthouse dial can't be original. The dial is in obvious need of
restoration, or at least conservation. Perhaps a nodus could be added. Once the
spacings of the azimuth lines have been measured, the trig to calculate the
nodus position is straigntforwrad.
Regards,
John D
--------------------------
Dr J Davis
Flowton Dials
________________________________
From: Frank Evans <[email protected]>
To: Sundial <[email protected]>
Sent: Thursday, 1 August 2013, 14:03
Subject: azimuth lines
Greetings, fellow dialists,
Attached is a picture of the dial on a lighthouse in North Shields, England
(55N 1.5W). It is probably from the eighteenth century and is badly eroded. As
well as its hour marks it has a series of vertical azimuth lines labelled with
the points of the compass. These may lie between the solstice curves. I am at a
loss as to how the lines would have worked. There is no sign of a nodus on the
gnomon (which looks old). Possibly, if there was a date scale associated with
the azimuth lines, now eroded away, then it would be possible to get the sun's
bearing from where the time line crosses the azimuth line but that looks pretty
cumbersome. Any suggestions?
Frank 55N 1W
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