Helmut
Sonderegger's program "Sonne" calculates shepherd or cylindrical dials corrected
for longitude and EoT. The program generates the location specific specific
drawings as in Fer's attachment. You can download "Sonne" from his website. http://web.utanet.at/sondereh/sun.htm
Roger Bailey
Walking Shadow
Designs
N 48.66 W 123.4
-----Original Message----- From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]On Behalf Of fer de
vries Sent: October 17, 2006 12:28 PM To: Gerard Hughes;
Sundial List Subject: Re: Heliochronometer card
dials?
Gerard,
You could make a sheperd's dial. These are
location specific.
Attached is a picture of the scale for such a
dial with correction for longitude and equation of time.
It would be better if you make two, one for the
morning hours and one for the afternoon hours.
Red cq blue lines in the picture.
Also a Capuchin dial for one latitude can be
corrected for longitude and EoT but also split the pattern in two
parts.
Correction for daylight saving time is no more
then adding new numbers to the dial.
Such altitude dial will not work accurate around
noon but the possibility to make them for clock time is present.
Best wishes, Fer.
Fer J. de Vries
Eindhoven, Netherlands lat. 51:30
N long. 5:30 E
----- Original Message -----
Sent: Tuesday, October 17, 2006 8:36
PM
Subject: Heliochronometer card
dials?
Ok, so I do realize
that "heliochronometer" and "card dial" are sort of
mutually exclusive. I’m looking for a way to make some easy to read card
dials that read in standard mean time.
I work at a number of
historical reenactment fairs and I’d love a quick and portable way to show
people how fun sundials can be and that sundials can be accurate. I have a
number of universal ring dials but they read LAT. I’d like the dial to read
in mean time because initially I’d like to be able to skip the explanation
of Local Apparent Time vs. Mean Time and such. I realize that
altitudinal card dials are not the most accurate, but since there is no such
thing as a pocket Schmoyer dial I’m looking for an alternative that offers
simplicity and a hook to catch people’s interest--and I'll be using them in
the summer so the sun will have some altitude for the dial to discern.
*
I’m
considering drafting latitude, longitude and date specific Capuchin dials
corrected for daylight savings and the equation of time. I realize these
dials would be one offs only of use at one location at one date, but since
card dials can be drafted fairly easily this seems like a reasonable way to
go. Granted, one can make a "universal" Capuchin dial that compensates for
latitude and the time of the year, but such a dial still reads in
LAT--Perhaps I could make two rotating hour wheels that line up with the
hour scale to set for daylight savings, longitude offset from the center of
the time zone and the equation of time (one for am and one for pm--I don't
think there is a way to make a single wheel work)
I’m wondering if
people have any alternate suggestions and ways to make drafting more
efficient on my Adobe CS2 equipped non-Intel Mac? (that is, I don't have
Delta CAD at the moment.)
Thanks, Gerard
*Others
may think that the path of the sun is fascinating as it is and doesn’t need
to be equated with mean time, but I, personally, didn’t become fascinated by
dialing until I discovered all the reasons why the dials I saw in parks
didn’t read clock time and I assume that others may be dismissive of
sundials for similar reasons.
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