Dear Dialists
I have augmented the information posted a few days ago regarding the
calculation of the analemma. There is now also a program that computes the
analemma for every hour and projects the analemmas onto a user defined
plane surface of arbitrary orientation, ie. horizonal, vertical,
equ
Can anyone out there direct me towards any information on
polarization sundials? Sky and Telescope published a short
article on one a few years back, but I haven't been able to find
anything else since.
Regards,
Dave Rose
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Hi John D.
you wrote:
>If we want a definition of the "Singleton" dial, it's a horizontal dial with
>polar-pointing style and showing standard time on 12 date rings. If we get
>to the stage where there are hundreds of these dials in existence (rather
>than just paper-ware), then we might need a
Hi all,
in a private message Mario Catamo has remarked that in the table of the
Sun's declination calculated by Thibaud Taudin-Chabot, and from him
published in his URL http://www.chabot.demon.nl/sundials/SunMeanGMT.htm,
there are some values different from those that are found on many books on
>I can see that in abstract terms that we have dials which are
>
>- projection of a point onto a surface (perhaps curved)
>- projection of a line (perhaps curved) onto a surface (perhaps curved)
>- projection of two lines (perhaps curved) onto a surface (perhaps curved)
>- other non-projection typ
Dear Dialists
In my humble opinion I think that discussions of exact dates when certain
events happen is not really relavent to
the design of a sundial. If one is interested in a dial measuring standard
clock time then one is interested in
the analemma. But the analemma is a relationship between
That was a short article but an interesting concept of " mapping" the lines on
a transparent medium and showing time where their shadow meets a point. A page
or two later in that Compendium, Fred Sawyer showed how a stained glass window
could apply the concept. I know Claude Hartman has done se
