Send reply to: "Fritz Stumpges" <[EMAIL PROTECTED]>
From: "Fritz Stumpges" <[EMAIL PROTECTED]>
To: "Sundial List" <[email protected]>
Subject: Classification
Date sent: Thu, 30 Mar 2000 07:26:31 -0800
Dear Fritz,
I encountered the same problem when I tried to find a practical way to
present my sundial picture collection on the web. I could not even find
English equivalents for two basic classes of sundial types, commonly
distinguished in the Dutch sundial literature. After some hesitation (being a
novice in the field of dialing) and asking the advice of Fer de Vries, I went
so
far to introduce English terms for these classes: "nodal sundial" and "pole-
style sundial". See:
http://www.biol.rug.nl/maes/welco-en.htm
Using "other" categories, I managed to get my pictures out, though. But I
would also love to see a more comprehensive classification scheme or
sundial typology!
The theoretical approach of J.A.F. de Rijk might be relevant here. I found it
in
the book "25 eeuwen tijdmeting" by Bruno Ernst (a pseudonym), Amsterdam
1988. It is in Dutch; I do not know whether English versions of his ideas have
been published.
He states that five parameters are involved:
- latitude (b)
- date (d)
- time (t)
- elevation of the sun (h)
- azimuth of the sun (a)
and that, given three of them, the other two can be calculated.
Sundials, then, can be classified according to which three parameters they
use to 'calculate' the other two, and he gives several examples of this
approach. He notes that the two sundial classes mentioned above (nodal and
pole-style) escape this approach, as they measure time directly.
It therefore seems that this approach does not provide a complete basis for
classification.
Yours,
Frans Maes
Peize, The Netherlands
[EMAIL PROTECTED]
www.biol.rug.nl/maes/
> Could someone please help direct me to more information on the
> classification of sundials. I see that John Davis' Glossary includes many
> definitions, but I was hoping to find one that was organized more like a
> flow chart or genealogy chart. Hopefully it would include basic types
> with lines to sub types and multiple lines for ones with several origins
> etc. How is the organizational system used by the Patient Office? I
> seem to remember it not being completely usable, or at least difficult to
> use, the way it is. Thank you, and I sure enjoy all of the dialog this
> list generates!
