Hi Steve,
I use to be a member of the NASS but I am retired now. And due to funds
I was not able to renew my membership. So I don't have access to Fred
Sawyer's and Bill Gottesman's article.
Maybe the Article and the drawing of the Earth with sundials could be
used to explain this?
Roderick.
On 3/04/2023 10:26 am, Steve Lelievre wrote:
You don’t need two wedges, you just skew the positioning to do both
adjustments in one.
If you have The Compendium vol 7 issue 1, take a look at the articles
by Fred Sawyer and Bill Gottesman.
Steve
On Sun, Apr 2, 2023 at 17:20, Rod Wall <rodwall1...@gmail.com> wrote:
Hi Jack and Steve,
To implement what Jack has indicated. You could have two wedges
one on top of each other. One for Latitude correction and one for
Longitude correction.
You could also just use a Longitude correction wedge if you only
wanted to correct for Longitude.
When writing instructions. Please also include people who live in
the southern hemisphere, we do also have sundials.
Do I have this correct?
Roderick.
On 3/04/2023 9:24 am, Steve Lelievre wrote:
Jack,
Try out my calculator! You can specify a time zone meridian for
the dial at its original location, or at its new location, or
both. If there is an effective longitude change, it'll tell you
how to position (twist) the dial on the wedge and how to orient
the wedge itself, turning it away (rotating it ) from the
meridian line.
Steve
On 2023-04-02 3:59 p.m., Jack Aubert wrote:
I thought about this briefly. I had always thought that the
purpose of the shim or wedge adjustment was to tip the dial
north or south so that dial is at the latitude it was originally
designed for. If the original dial has a built-in longitude
correction, that could also be factored into a wedge which would
have both a north-south and east-west axis. But a wedge would
not work if it moved the gnomon out of alignment with the with
the rotation of the earth (or the celestial sphere). I think a
longitudinal adjustment would only work if he original dial had
a time-zone offset included by rotating the hour lines with
respect to the origin of the gnomon.
Does this make sense? It sounds like a good project for a 3-D
printer.
Jack
*From:* sundial <sundial-boun...@uni-koeln.de>
<mailto:sundial-boun...@uni-koeln.de> *On Behalf Of *Steve Lelievre
*Sent:* Sunday, April 2, 2023 5:16 PM
*To:* Michael Ossipoff <email9648...@gmail.com>
<mailto:email9648...@gmail.com>
*Cc:* Sundial List <sundial@uni-koeln.de>
<mailto:sundial@uni-koeln.de>
*Subject:* Re: Adjusting dial to new location
Michael,
Yes, I recognize that to get Mean Time involves Equation of Time
adjustment and that Equation of Longitude can be handled there
to give Standard Time (or DST).
But anyway, my inquiry was to seek an online wedge calculator.
Nobody identified one and a week seemed an adequate wait for
responses, so I've just written one. Anyone who's interested,
please see
https://sundials.org/index.php/teachers-corner/sundial-construction/367-easy-dial-adjustment-for-your-latitude
Cheers,
Steve
On 2023-04-02 1:41 p.m., Michael Ossipoff wrote:
I just want to mention that the shim under the north or
south edge of the dial is only for latitude. Longitude is
corrected-for by changing the constant term of the
Sundial-Time to Clock-Time conversion.
But usually Sundial-Time, Local True Solar Time, is what I’d
want from a sundial.
On Sun, Mar 26, 2023 at 14:30 Steve Lelievre
<steve.lelievre.can...@gmail.com> wrote:
Hi,
Can anyone point me to an existing online calculator for
making a wedge
to adjust a horizontal dial to a new latitude and longitude?
I am not asking for an explanation of how to do the
calculation; I just
want to be able to point people to a calculator that has
already been
proved on the internet. It should use the original
location (latitude
and longitude) and the new location to calculate the
angle of slope of
the wedge and the required rotation from the meridian.
Many thanks,
Steve
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