Peter Mayer wrote:
> A while back Gerard Hughes started a thread on accurate card dials:
> I've often thought that if I have the time, I'll write the DeltaCad
>code to generate the EoT adjustment for the Merchant dial. But if
>someone else has the leisure to do it first, I'll be the first to applaud!
'Leisure' is a good word in this context as it took me best part of a
month to calculate all the tiny offsets and then convert them into
separatly rotated 'verniers' for each month for my Lindi/SOL
heliochronometer which is, as yet, only 80% completed after three years
in the making as I keep changing my mind about the sun sighting
arrangement.
Clever though it is, some aspects of the original P&G SOL Horometer I
found somewhat clumsy. ("An ugly dial with an ugly name" as I believe Mr.
Gibbs called it). That swivelling blunt 'arrow' pointer for longitudinal
offset for example. My LindiSOL incorporates an additional central
'ring' which allows for both daylight saving AND longitudinal offset
adjustment.
The plate artwork is in Mac Adobe Illustrator format but I can send a PDF
and jpeg of the finished plates and base if anyone is interested.
Tony Moss
Lindisfarne Sundials.
P.S. I have heard it suggested that Pilkington only calculated the first
and last of the 'vernier' line angles with equal spacing in between.
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