Largest stone sundial?

[Dan-George Uza]

Hello,

Does anybody know what the largest one-piece stone sundial in the world is?

Thanks,


-- 
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DeltaCad has been discontinued

[Dan-George Uza]

Hello,

I've just found out that DeltaCad has been discontinued so you won't be
able to download the demo any longer. I find this very sad, it was a very
simple CAD software with many useful sundial macros available. However, it
seems that you will still be able to download your purchased copy.

Best wishes,

-- 
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Norths align in the UK

[Dan-George Uza]

Hello,

This is interesting:
https://www.ordnancesurvey.co.uk/newsroom/blog/magnetic-true-grid-north-align-over-great-britain

Cheers,

-- 
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Shadow art

[Dan-George Uza]

Hi,

Not quite sundials but interesting nevertheless.
http://kumiyamashita.com/light-shadow

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Right ascension on sundials

[Dan-George Uza]

Hello,

Are there sundials showing the Sun's right ascension? Can you please post a
photo? Thanks!

Dan Uza
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Re: U.S. Senate approves bill to make daylight saving time permanent

[Dan-George Uza]

According to opinion polls, Romanians are about 50%-50% for permanent DST
vs. permanent standard time, but the permanent DST crowd seems to be more
vocal. Legislation is bogged down right now but in the current form it
appears to favour permanent standard time.

Dan Uza

On Wed, Mar 16, 2022 at 1:13 PM Kurt Niel  wrote:

> It is still a shame, that DST is really that prominent. I stay in Europe
> and hope we can get rid of it - dammned DST.
>
> I am still very emotional about it and see it as one of many homan made
> mistakes.
>
> Kurt
>
> Steve Lelievre  schrieb am Di., 15. März
> 2022, 22:51:
>
>>
>> It seems the USA may be getting ready to abolish seasonal clock
>> changes.  The proposal has just passed in the Senate but still has to be
>> accepted by the House of Representatives, so we can't celebrate yet. (
>>
>> https://www.reuters.com/world/us/us-senate-approves-bill-that-would-make-daylight-savings-time-permanent-2023-2022-03-15/
>> )
>>
>> If it happens, Canada would quickly follow. In fact, here in British
>> Columbia it's already in law that we will switch to permanent DST once
>> Washington (state), Oregon and California have switched. The EU is
>> already on the same path but things have got bogged down with some
>> member countries yet to decide which timezone to adopt. EU-wide
>> preparations were further delayed due to the pandemic (
>>
>> https://www.thelocal.it/20211029/clocks-to-go-back-in-italy-despite-eu-deal-on-scrapping-hour-change/
>> ).
>>
>> I would have preferred permanent Standard Time over permanent
>> Daylight-saving Time but, even so, I hope the plans proceed. It will
>> certainly simplify the my designs for Civil Time sundials and Equation
>> Of Time signage.
>>
>> Cheers, Steve
>>
>> -----------
>> https://lists.uni-koeln.de/mailman/listinfo/sundial
>>
>> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>

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Astrolabe auction

[Dan-George Uza]

Dear all,

Mishail Ivanov informed me of this auction for a Persian astrolabe:

https://www.liveauctioneers.com/item/123871365_persian-astrolabe-c-17th-century

-- 
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New sundial book (in French)

[Dan-George Uza]

Dear all,

I've learned about Denis Savoie's new sundial book which was published a
couple of months ago and I though I'd let you know.

"Une Histoire des cadrans solaires en Occident"

https://www.lesbelleslettres.com/livre/9782251452319/une-histoire-des-cadrans-solaires-en-occident

Cheers,

Dan Uza
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Sun mirror in Norway

[Dan-George Uza]

Hello,

Not really a sundial, but interesting!

https://edukalife.blogspot.com/2015/09/the-giant-sun-mirrors-of-rjukan-amazing.html


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Re: A mis-aligned vertical dial

[Dan-George Uza]

Dear all,

In his book "Sundials Old and New", A. P. Herbert contends that rotating a
vertical dial by 15 degrees towards East (i.e. gnomon pointing 15 deg. West
of North) will switch it to Summer Time. Writing that this is against all
theory, but works quite well, he calls this "the housewife's trick" (page
80). I find it intriguing.

Dan Uza

lun., 8 nov. 2021, 23:50 Francesco Caviglia  a
scris:

> Dear John,
> attached you will find a graph calculated at latitude 42 degrees N
> for a vertical sundial mis-aligned by 1 degree toward West.
> For 52,5 degrees the values are somewhat larger (by about 10 to 30%).
> With greater mis-alignement (to some degrees) consider
> that the values are roughtly proportional to the mis-alignement itself.
> The original declination of the vertical dial has no influence on the
> error,
> just he mis-aligment matters.
>
> The graphs show the difference:(value indicated by the mis-aligned
> sundial) - (true value)
> They refer to the Time (above) and to the Solar declination (below),
> the value are expressed as a function of the True Time (Ora reale) of the
> day,
> at the equinoxes and at the solstices.
>
> In any case, to find the errors it is quite simple:
> just take the classical graph with the curves
> showing the elevation of the Sun as a function of the Azimuth
> for a set of Hours and Solar Declinations.
> Make a transparent copy of the graph,
> shift it in Azimuth as the considered sundial
> and paste it on the original graph.
> On every point in the plane of the graph you can read
> the values of the real Time and Declination (on the original graph)
> and those indicated in the same moment by the misaligned sundial (on the
> shifted graph).
>
> Best wishes
>  Francesco Caviglia
>
>
> > If a vertical dial is relocated and now faces a few degrees east or west
> of
> > its designed declination, you might expect it to run a few minutes slow
> or
> > fast.  Has anyone ever tabulated the greatest error, and at what times
> and
> > dates it occurs?  And does it make sense to think about the average
> error?
> > Clearly the errors depend on the latitude and the design declination, but
> > for starters they could be tabulated just for a direct south dial at 52.5
> > degrees N,  and for a location move of 1, 2 and 5 degrees either way.  As
> > the gnomon is no longer polar-pointing I imagine the maths is a bit
> hairy.
> >
> > Best wishes,
> >
> > John Foad
> >
> >
> >
>
> Francesco CAVIGLIA
> via SAFFI 21
> 10138 Torino
> tel. 011 4333703
> mob. 3356121207
> francesco.cavig...@tin.it
> ---
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>
>
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The German 2021 Sundial Conference - an Afterthought

[Dan-George Uza]

Dear all,

For those interested in current gnomonic events: I would like to mention
that there has been a sundial conference near Mannheim in Germany between
5-8 August which I had the pleasure to attend and post some photos on my
Facebook account.

The presentations (in German language) covered many interesting topics,
ranging from sundial history, sundial books, sundial funding programs,
sundial quizzes to modern technology applied to sundial manufacturing.
The circa 70 participants also had fun visiting local gnomonic sights in
and around Birkenau in the Odenwald - a small town which holds an
international record for the highest sundial density (8 sundials/square
km). All attendees received an anniversary medal and a jubilee album, gifts
which will also be sent to partner sundial organizations.

It was quite a special reunion since this year the German sundial working
group (Fachkreis Sonnenuhren) celebrates its 50th anniversary. The group is
part of the German Society for Timekeeping, a larger organization dealing
with various areas of horology.

I would like to thank the organizers for this wonderful and stimulating
conference! I am already looking forward to next year's meeting.

PS: If you would like to know more about the local sundials, I highly
recommend the new book "Sonnenuhren in Birkenau" ("Sundials in Birkenau").
It's also in English and French, available via i...@sonnenuhren-birkenau.de

--
Dan-George Uza
Romania
---
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Books about Sundials in Romania

[Dan-George Uza]

Hello,

You may be interested to know that a couple of books about sundials in
Romania have been printed in recent years which are still available. In
chronological order they are:

1) "Cadrane solare din Transilvania, Banat, Crişana şi Maramureş" /
"Sundials from Transylvania, Banat, Crișana and Maramureș" by myself (2014,
276 pages, Romanian language with an English abstract)
2) "Sundials from Cluj County, Romania" by myself (2020, 69 pages, full
English, Romanian language version is also available)
3) "Erdély napórái" / "Sundials from Transylvania" by Miholcsa Gyula (2020,
419 pages, Hungarian language with an English abstract).

All are available for purchase at
https://astromix.ro/product-category/carti/ and can be shipped
internationally. You can select your prefered language by clicking on the
flag in the upper right. Prices are in local currency, with 50 Romanian Lei
being about 10 Euro. If you are interested just let me know and I will
check shipping costs depending on the ordered weight and your exact
location.
"Sundials from Cluj County, Romania" is also available either as
paperback copy or E-Book directly from Amazon (.com, .co.uk, .de, .it etc.)

Best regards,

-- 
Dan-George Uza
---
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Sundial website template with map

[Dan-George Uza]

A happy new year to all of you!

I know that some national organisations (like the GSA in Austria or MCSE in
Hungary) display their national sundial catalogue on their website in an
embedded Google Map.

Can you please recommend a template for such a website - preferably cheap
or even free? Ideally it should work for Wordpress and should be using Open
Street Map instead of Google Maps. The user should be able to click the
placemark and get a photo and a few basic infos about each sundial.
Importing locations from a spreadsheet should also be possible.

Thanks,


Dan Uza
---
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Re: English native speaker wanted

[Dan-George Uza]

Wow so many people writing me to offer their help!
Thanks everyone, I will get back to you soon.

Dan

On Wed, Sep 16, 2020 at 12:28 PM Dan-George Uza 
wrote:

> Hello,
>
> I'd like to publish a booklet about the sundials in my area... and I've
> decided that it's going to be in English.
>
> So I would really need one or two native English speakers (preferably with
> a previous background in literature) to make sure everything's in order
> with my text. There are about 20 A4 pages for you to review. I can offer a
> signed paperback copy as a modest thank you gift once I get it published.
>
> Would anyone here be interested?
>
> Thanks,
>
> --
> Dan-George Uza
>


-- 
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English native speaker wanted

[Dan-George Uza]

Hello,

I'd like to publish a booklet about the sundials in my area... and I've
decided that it's going to be in English.

So I would really need one or two native English speakers (preferably with
a previous background in literature) to make sure everything's in order
with my text. There are about 20 A4 pages for you to review. I can offer a
signed paperback copy as a modest thank you gift once I get it published.

Would anyone here be interested?

Thanks,

-- 
Dan-George Uza
---
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Islamic time measurement

[Dan-George Uza]

Hello,

As you know the times of the five daily prayers in Islam are dependent on
the position of the sun.

What you may not know is that also dependent on the sun are some instances
when you should NOT pray.

One of those rules states that it is forbidden to pray from sunrise until
the sun has ascended to the length of a spear above the horizon.

Although I have found modern sources quoting this height to be 4.5 or 4.25
degrees, I did not find any details on how they used to perform this
measurement in the past using an actual spear.

In my country's popular literature (mostly fairy tales) there is also this
way of measuring time. Often events are reported to occur when the Sun's
height reaches 1, 2 or 3 spear heights on the sky. This cultural connection
is quite understandable because the old provinces that make up modern-day
Romania were under the influence of the Ottoman Empire for a good part of
the Middle Ages.

Can anyone explain how Muslims used the spear length to measure the height
of the sun back in the days?


-- 
Dan-George Uza
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Aperture nodus geometry

[Dan-George Uza]

Hello,

I'm a big fan of meridian lines inside churches and I know these are sort
of camera obscura sundials.

While I understand the geometry behind pinhole camera projections I can't
seem to find any help on how the solar image forms after the rays pass a
sizeable aperture nodus (for example a vertical 25cm nodus projected onto a
wall 10 meters away) and how the ratio of hole size vs. projection distance
affects the size and fuzzyness of the final projected image. So what's the
geometry behind that?


PS: Some sources refer to the projected image as "stenopaic image". Is this
universally acceptable?

-- 
Dan-George Uza
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Denizli sundial

[Dan-George Uza]

Hello, I've just read about the discovery of an antique sundial in Turkey.

https://www.dailysabah.com/life/history/2000-year-old-sundial-unearthed-in-southern-turkeys-denizli

Best regards,

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Sunrise time glitch?

[Dan-George Uza]

Hello all,

While doing some research for a paper, a friend of mine noticed peculiar
differences regarding sunrise times for his city (Alba Iulia, Romania).
They occur both on TimeAndDate.com as well as suncalc.org and -so far I can
tell- only in Romanian cities (Berlin and Vienna are okay).

I figure sunrise times should be pretty much the same except for the leap
year cycle, but for example between December 1st 1930 and December 1st 1931
the times differ by more than 15 minutes. What could be the cause?

I also looked at Gian Casalegno's Sun Ephemeris and all the times check out
neatly there.

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Amazfit Bip watchface

[Dan-George Uza]

Hello,

Is there any gnomonic watchface for the Amazfit Bip smartwatch? To display
EOT, LAT, declination etc.

Thanks,

-- 
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---
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Sundial designs against vandalism

[Dan-George Uza]

Hello,

Horizontal sundials are often victims of vandalism. I am looking for ideas
or designs of gnomons which are not that easy to break off i.e. how to
attach them permanently to the base plate.  Can you help?

Thanks,

-- 
Dan-George Uza
---
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Romanian Conference on Cultural Astronomy

[Dan-George Uza]

Dear all,

Please find below the invitation to our yearly national conference in
Romania. I would really enjoy meeting you there.

This year we also plan to have an exhibition on planispheres. If you
would like to contribute with items please let me know.

Best wishes,

Dan Uza


-- Forwarded message -
From: Societatea Romana pentru Astronomie Culturala <
cont...@astronomieculturala.ro>
Date: Tue, Sep 3, 2019 at 8:46 AM
Subject: 3rd SRPAC Conference on Cultural Astronomy / A 3-a Conferință a
SRPAC despre Astronomie Culturală
To: 


Dear colleagues / Dragi colegi,

(mesajul în limba română este mai jos)

It is my pleasure to invite you to our 3rd conference of the Romanian
Society for Cultural Astronomy (SRPAC) in Timisoara, Romania, held on
Nov 15-17, 2019. Two days of talks and meetings plus one day reserved
for trips to nearby archaeoastronomical sites. The event gathers each
year 20+ researchers, teachers, and amateurs from Romania and
neighboring countries. Last year the president of SEAC delivered an
online talk to our conference.

The sessions will include: archaeoastronomy, ethnoastronomy, history of
astronomy and space exploration, impact of astronomy on our daily lives,
astronomy & education. Full papers will be published after the
conference in March 2020 in our yearly conference post-proceedings with
ISSN as well as on academia.edu as a pdf after 1 year.

The website has all the details you need:
https://sites.google.com/view/comunicarisrpac/home-en (registration
included).

Deadline for registering the authors and abstracts is 15 Oct, 2019.

We offer free accommodation in our university guest house (limited on a
first come first served basis). Timisoara is reachable via low cost
flights from many places in Europe (London, Paris, Madrid, etc.) and by
car in about 3-8 hours from central Europe, Bulgaria, Ukraine, etc.

We hope to see you in Timisoara at this special event paving the way for
a better astronomy in culture approach in Romania.


Best regards,

Marc Frincu

President of SRPAC



Cu mult drag vă informez că a 3-a ediție a sesiunii de comunicări a
SRPAC va avea loc între 15-17 noiembrie 2019 la Timișoara. Primele 2
zile sunt rezervate pentru prezentări și întâlniri, a treia zi este
pentru vizite la situri arheoastronomice.

Sesiunile includ: arheoastronomie, etnoastronomie, istoria astronomiei
și a explorării spațiului, impactul astronomiei în viața cotidiană,
astronomia și educația.

Pe pagina de internet găsiți toate detaliile necesare:
https://sites.google.com/view/comunicarisrpac.

Termenul pentru înscriere este 15 octombrie 2019.

Se oferă cazare gratuită în căminele Universității de Vest (locuri
limitate - primul venit primul servit). Putem rambursa parțial drumul
spre Timișoara în funcție de fonduri și număr de cereri.


Cu deosebită considerație,

Marc Frîncu

Președintele SRPAC



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Re: Sunrise/sunset in old calendars/almanacs

[Dan-George Uza]

Hello again,

Here is the complete data with the exception of the first three months
which have been lost:

April 1793 - sunrise: 5:20 and sunset: 07:14
 - day length - 13 hours and 20 minutes, night - 10 hours
and 40 minutes

May 1793 - sunrise: 4:33 and sunset: 07:47
 - day length - 14 hours and 54 minutes, night - 9 hours
and 6 minutes

June 1793 - sunrise: 4:05 and sunset: 07:47
 - day length - 14 hours and 53 minutes, night - 9 hours
and 7 minutes

July 1793 - sunrise: 4:12 and sunset: 07:44
 - day length - 15 hours and 36 minutes, night - 8 hours
and 24 minutes

August 1793 - sunrise: 4:51 and sunset: 06:39
 - day length - 14 hours and 18 minutes, night - 9 hours
and 42 minutes

September 1793 - sunrise: 5:41 and sunset: 05:29
 - day length - 12 hours and 38 minutes, night -11 hours
and 22 minutes

October 1793 - sunrise: 6:24 and sunset: 05:20
 - day length - 10 hours and 52 minutes, night - 13 hours
and 8 minutes

November 1793 - sunrise: 7:24 and sunset: 04:21
 - day length - 9 hours and 12 minutes, night - 14 hours
and 38 minutes

December 1793 - sunrise: 7:54 pm and sunset: 4:05 pm
 - day length - 8 hours and 12 minutes, night - 8 hours and
48 minutes


Dan Uza

On Fri, Aug 9, 2019 at 10:50 PM Dan-George Uza 
wrote:

> Dear Steve,
>
> I will share the data for the whole year once I get it (I only have
> April). Your preliminary results sound too good to be true.
> I did a simulation using TimeAndDate.com for three completely different
> locations on the European continent: Constanta (Romania), Gorlitz (Germany)
> and London (UK). I chose these because of their proximity to the time zone
> meridians, this way the old solar time is more easily found (I just exclude
> 1h daylight saving time).
>
> The stated duration of the day of 13h20min for April is recorded in those
> localities on April 13, April 7, respectively April 7 (all gregorian, the
> last two cities have approximately the same latitude).
> Sunrise on these respective dates (in solar time): 5:24 in Constanta, 5:23
> in Gorlitz, 5:23 in London.
> Sunset (in solar time): 18:47 at Constanta, 18:42 at Gorlitz, 18:43 at
> London.
>
> In the calendar we've got sunrise at 5:20, which is a good enough fit for
> all the above examples.
> On the other hand, sunset is at 7:14 (p.m.) and this time doesn't fit any
> of the examples above.
> If we consider it to be the civil twilight, we have 19:16 for Constanta,
> 19:16 for Gorlitz, respectively 19:17 for London (old hours). These
> correspond quite well with the sunset given by the calendar.
>
> Dan Uza
>
> On Fri, Aug 9, 2019 at 10:15 PM Steve Lelievre <
> steve.lelievre.can...@gmail.com> wrote:
>
>> Dan,
>>
>> Using only your April data, and assuming:
>>
>> 1. day length is the difference of the sunset and sunrise (as opposed to
>> the daylength stated),
>> 2. sunrise and sunset are when the center of the sun is on the horizon
>> 3. my modern source of solar declination data is "good enough"
>> 4. your table of values is for the Julian calendar, which for the year in
>> question is offset from the Gregorian calendar by 11 days,
>>
>> then, by varying latitude to minimize the Sum of Squares of the
>> differences between true day lengths and the representative day length
>> stated  I get a latitude of 44.413N, which would correspond to
>> Bucarest.
>>
>> If I could use your table of data for the full year, the result would of
>> course be different - better, I would hope, but possibly not!
>>
>> As yet, I have no idea why the stated day length is not the same as the
>> difference of the sunrise and sunset.
>>
>> Steve
>>
>>
>> On 2019-08-09 1:06 a.m., Dan-George Uza wrote:
>>
>> Hello all,
>>
>> I have seen an old calendar from 1793 which lists for every month sunrise
>> and sunset times as well as day and night duration. For example, taking the
>> month of April: sunrise at 5 h 20 m, sunset at 7 h 14 m; day length 13 h 20
>> min, night length 10 h 40 m.
>>
>> Somebody asked me if it would be possible to establish the approximate
>> geographical area for these predictions.
>>
>> I'm pretty sure it's not possible. Back then they used true solar time
>> (or perhaps mean solar time?) so I guess these hours would have been valid
>> for a whole parallel of latitude, with variations once you go north or
>> south.
>>
>> Nevertheless, I made a simulation and realized that I cannot get close to
>> these numbers. I don't know why. Perhaps because back then sunrise and
>> sunset was not

Re: Sunrise/sunset in old calendars/almanacs

[Dan-George Uza]

Dear Steve,

I will share the data for the whole year once I get it (I only have April).
Your preliminary results sound too good to be true.
I did a simulation using TimeAndDate.com for three completely different
locations on the European continent: Constanta (Romania), Gorlitz (Germany)
and London (UK). I chose these because of their proximity to the time zone
meridians, this way the old solar time is more easily found (I just exclude
1h daylight saving time).

The stated duration of the day of 13h20min for April is recorded in those
localities on April 13, April 7, respectively April 7 (all gregorian, the
last two cities have approximately the same latitude).
Sunrise on these respective dates (in solar time): 5:24 in Constanta, 5:23
in Gorlitz, 5:23 in London.
Sunset (in solar time): 18:47 at Constanta, 18:42 at Gorlitz, 18:43 at
London.

In the calendar we've got sunrise at 5:20, which is a good enough fit for
all the above examples.
On the other hand, sunset is at 7:14 (p.m.) and this time doesn't fit any
of the examples above.
If we consider it to be the civil twilight, we have 19:16 for Constanta,
19:16 for Gorlitz, respectively 19:17 for London (old hours). These
correspond quite well with the sunset given by the calendar.

Dan Uza

On Fri, Aug 9, 2019 at 10:15 PM Steve Lelievre <
steve.lelievre.can...@gmail.com> wrote:

> Dan,
>
> Using only your April data, and assuming:
>
> 1. day length is the difference of the sunset and sunrise (as opposed to
> the daylength stated),
> 2. sunrise and sunset are when the center of the sun is on the horizon
> 3. my modern source of solar declination data is "good enough"
> 4. your table of values is for the Julian calendar, which for the year in
> question is offset from the Gregorian calendar by 11 days,
>
> then, by varying latitude to minimize the Sum of Squares of the
> differences between true day lengths and the representative day length
> stated  I get a latitude of 44.413N, which would correspond to
> Bucarest.
>
> If I could use your table of data for the full year, the result would of
> course be different - better, I would hope, but possibly not!
>
> As yet, I have no idea why the stated day length is not the same as the
> difference of the sunrise and sunset.
>
> Steve
>
>
> On 2019-08-09 1:06 a.m., Dan-George Uza wrote:
>
> Hello all,
>
> I have seen an old calendar from 1793 which lists for every month sunrise
> and sunset times as well as day and night duration. For example, taking the
> month of April: sunrise at 5 h 20 m, sunset at 7 h 14 m; day length 13 h 20
> min, night length 10 h 40 m.
>
> Somebody asked me if it would be possible to establish the approximate
> geographical area for these predictions.
>
> I'm pretty sure it's not possible. Back then they used true solar time (or
> perhaps mean solar time?) so I guess these hours would have been valid for
> a whole parallel of latitude, with variations once you go north or south.
>
> Nevertheless, I made a simulation and realized that I cannot get close to
> these numbers. I don't know why. Perhaps because back then sunrise and
> sunset was not counted by solar limb, but by geometric center of the Sun?
> How did they do it?
>
> Regards,
>
> --
> Dan-George Uza
>
> ---https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>

-- 
Dan-George Uza
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Sunrise/sunset in old calendars/almanacs

[Dan-George Uza]

Hello all,

I have seen an old calendar from 1793 which lists for every month sunrise
and sunset times as well as day and night duration. For example, taking the
month of April: sunrise at 5 h 20 m, sunset at 7 h 14 m; day length 13 h 20
min, night length 10 h 40 m.

Somebody asked me if it would be possible to establish the approximate
geographical area for these predictions.

I'm pretty sure it's not possible. Back then they used true solar time (or
perhaps mean solar time?) so I guess these hours would have been valid for
a whole parallel of latitude, with variations once you go north or south.

Nevertheless, I made a simulation and realized that I cannot get close to
these numbers. I don't know why. Perhaps because back then sunrise and
sunset was not counted by solar limb, but by geometric center of the Sun?
How did they do it?

Regards,

-- 
Dan-George Uza
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Can a sundial disprove Flat Earth?

[Dan-George Uza]

Hello,

In my country there is this growing Flat Earth movement akin to religious
fundamentalism. No matter what you throw at them, they simply ignore it.
There is even a big group on Facebook of about 5,000 users. I recently
joined there for fun. First I thought they were joking, but everybody seems
dead serious about it. I nearly got kicked out because my profile photo
shows a large armillary sundial which they consider to be a globe So
preposterous! :)

So I recently wondered: can a sundial can be used to prove the Earth is
round? And what would be the simplest gnomonic proof for this?

Dan Uza
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Temporal hours to modern hours

[Dan-George Uza]

Hello,

In a note quoted below from the "Dictionary of Greek and Roman Antiquities,
John Murray, London, 1875" I found the following advice to convert temporal
hours to modern hours.

*"A very quick and easy rule of thumb, when we read "the third hour, the
sixth hour", etc., is to add 3, 6, etc. to 5:00 A.M.: The first hour, for
example, runs from roughly 6 to roughly 7 A.M.; and the ninth hour from
roughly 2 to roughly 3 P.M."*

Source:
http://penelope.uchicago.edu/Thayer/E/Roman/Texts/secondary/SMIGRA*/Hora.html

Of course back then there was no summer time either...

But is there a closer aproximation for this, perhaps using a simple
mathematical formula? Are there apps that can convert temporal hours
directly to modern equivalents, perhaps as a spreadsheet?

Dan Uza
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Paper templates for Roman Sundials

[Dan-George Uza]

Dear all,

I'm looking for examples of Roman Sundials that can be printed, cut out and
assembled. Something not too difficult so that potentially a child could do
it.

I found some examples on http://sundialatlas.net (APP 37, 38, 41).

How about a Pelekinon?
And would a shepherd sundial be Roman enough?

Best regards,
Dan Uza
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: ​Reinhold Kriegler

[Dan-George Uza]

I am shocked and saddened by this terrible news. Although I did not have
the chance to meet Reinhold in person, we had a very interesting
correspondence during the last few years. He was very active and had such a
rich contribution to this field. He once confessed to me that he hoped his
website reminded us of him and his interests once he was gone...

My condolences to his family and all who knew him.

Dan Uza
Romania

On Tue, Mar 26, 2019 at 7:46 AM Martha A. Villegas V. via sundial <
sundial@uni-koeln.de> wrote:

> Diese Nachricht wurde eingewickelt um DMARC-kompatibel zu sein. Die
> eigentliche Nachricht steht dadurch in einem Anhang.
>
> This message was wrapped to be DMARC compliant. The actual message
> text is therefore in an attachment.
>
>
> -- Forwarded message --
> From: "Martha A. Villegas V." 
> To: sundial@uni-koeln.de
> Cc:
> Bcc:
> Date: Tue, 26 Mar 2019 05:43:51 + (UTC)
> Subject: Our sundial friend Reinhold Kriegler
> Sundial friends,
>
> Reinhold Kriegler had many contributions to the gnomonic field, I am sure
> many of you had the chance to be in contact with him.
> With deep sadness I want to communicate that my dear friend Reinhold
> passed away on Saturday 23th in Dessau.
>
> His rich web http://www.ta-dip.de  is still working; you can find a lot
> of interesting information on it.
>
> Rest in peace.
>
> Greetings to all of you
>
> Martha A. Villegas (from Mexico)
>
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
---
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Dr. Rüter Sundial

[Dan-George Uza]

I've never seen one of these before.

https://www.ebay.de/itm/Original-Dr-Ruter-Sonnenuhr-Berlin-1946-Kompass-Uhr/382722122995

Once you push a button, the dial plate with gnomon seems to rotate by
compass so as to align with magnetic north showing both summer time and
winter time. I guess small adjustments are also possible (therefore the +
and - markings).

Dan Uza
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Historic sundials

[Dan-George Uza]

Hello!

If you were to make a presentation addressed mainly to schoolchildren or
early college about some important historic sundials, which ones would you
choose and why? I would be interested in your shortlist, perhaps a top 5 of
historic sundials?

Best wishes,

Dan Uza
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: dischrony

[Dan-George Uza]

Perhaps "equation of longitude"?

Dan Uza

On Wed, Mar 13, 2019, 20:50 Julian Lush  wrote:

> How about longitude adjustment?
>
> Julian Lush
> 72 Bromfelde Road, London SW4 6PR
> 020 7622 949707815 637706
> --
> *From:* sundial  on behalf of Frank King <
> f...@cl.cam.ac.uk>
> *Sent:* 13 March 2019 12:29
> *To:* Dan-George Uza
> *Cc:* Sundial List
> *Subject:* Re: dischrony
>
> Dear All,
>
> I have a mild distaste for "correction" since
> it implies something is wrong.  In particular
> 'local mean time' and 'local mean time-zone time'
> are both correct, but different, times.  One is
> offset from the other but this offset is in no
> sense a correction!
>
> To me "offset" is neutral.
>
> There are, of course, many many different
> times in current use.  Here are just a few:
>
>   TAI, UTC, UT1, UT2, GMT, GST, GPS time
>
> None of these is wrong but each is offset
> from all the others.
>
> Sometimes the offset is constant such as
> the difference between TAI and GPS time
>
> Sometimes the offset changes infrequently,
> such as the difference between TAI and UTC
> (which changes only when there is a leap
> second).
>
> Sometimes the offset changes continuously,
> such as the difference between GST (sidereal
> time) and GMT.
>
> This suggests that the word 'constant' is
> not generally appropriate and is why I am
> not keen on the Italian "costante locale".
>
> This is actually a false assertion when
> referring to local mean time versus local
> time-zone time because in most places the
> reference time zone is shifted 15 degrees
> backwards and forwards at the whim of
> legislators!  The offset is not constant!
>
> Dan-George asks:
>
>   how would you translate the Italian
>   "foro gnomonico"
>
> In English, this translates literally as
> "gnomonic hole" but this would be a bad
> translation!  It generally refers to the
> hole in the roof (or possibly a side wall)
> of a cathedral or large church that lets
> in the sun so as to cast an image of the
> sun on the floor.
>
> The best English equivalent is "aperture
> nodus" but that isn't quite the same thing.
> An aperture nodus provides a spot of light
> on the dial plate, not an image of the sun.
>
> The French "oeilleton" is more challenging!
> In English, this translates literally as
> "eye-cap" which I think of as something
> for medical use, for washing your eyes.
>
> I rather suspect that the French also use
> this to mean aperture nodus but I should
> like confirmation.
>
> Frank
>
> Frank King
> Cambridge, U.K.
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
---
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Re: dischrony

[Dan-George Uza]

By the way: how would you translate the Italian "foro gnomonico" or the
French "oeilleton"?

Dan Uza

On Tue, Mar 12, 2019 at 2:02 PM Frank King  wrote:

> Dear Fabio,
>
> An interesting message...
>
> > In Italy some sundials show the
> > written 'costante locale'...
>
> I find Italian gnomonic vocabulary great
> fun.  There are technical terms which
> sound very good in Italian but sound very
> odd when directly translated into English.
>
> I especially enjoy 'Foro gnomonico' and
> 'Meridiana a camera oscura'.
>
> I share your dislike of 'costante locale'.
> This could be interpreted in many ways.
> Is it the height above sea level or the
> local latitude or something else?
>
> In English I often use the word 'offset'
> and this can be 'an angular offset' or
> 'a time offset' or 'a displacement offset'
> and for 'costante locale' I would usually
> write:
>
> the local longitude offset
>
> It helps that in England, the local
> reference meridian is Greenwich but
> to be more precise I would write:
>
>   the longitude offset from the
>   reference meridian for the local
>   time zone
>
> From where I am sitting:
>
>   My longitude offset (from the
>   Greenwich meridian) is one-eighth
>   of a degree east or 30 seconds of
>   time.
>
> 'Offset' is used for angles, time
> or distance.
>
> Frank
>
> Frank King
> Cambridge, U.K.
>
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
---
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Re: dischrony

[Dan-George Uza]

Dear Fabio,

I use "longitude correction" ("corectie de longitudine"), but also
"meridian correction" ("corectie de meridian") would sound okay in Romanian.

Ciao,

Dan

On Tue, Mar 12, 2019 at 12:55 PM fabio.sav...@nonvedolora.it <
fabio.sav...@nonvedolora.it> wrote:

> hi all, I've a matter to put to you.
>
> In Italy some sundials show the written 'costante locale', that can be
> translated as 'local constant'.
> The authors of these sundials use this expression meaning the time
> difference between the Local Sun Time and the Time-Zone Sun Time.
> This 'local costant' is an angle if it highlights the difference of
> longitude or a time if it highlights the difference between the two Sun
> Time.
>
> I don't really like this expression. I think that the term 'costant' is
> misleading: the shown value depends on the selected meridian, it could
> not be that of the Time-Zone (e.g, outside UK, the one of the national
> observatory used in the past).
> Moreover the term suggests that there is a not better identified costant
> in that location but it isn't a costant, it is a choice on how to show
> the time.
>
> I started to look for a more proper expression.
> I'd like to know if there are any terms used in other languages, may be
> that a proper expression already exists.
> Anyway I found two italian terms that I think to propose as an
> alternative to the italian diallists, these terms may be used also in
> english so I'd like to know your thoughts.
> The first term is 'dislocation' (dislocazione), it means a different
> location and it refers to an angle.
> The second one is 'dischrony' (discronia) and it means a different time.
> This terms is curious because it rarely appears on the italian
> dictionaries, it is a technical term used in the medical field to
> indicate the cause of the 'jet lag' (while dysrhythmia is used for the
> effects), that is: to live with a different time.
>
> ciao Fabio
>
>
> --
> Fabio Savian
> fabio.sav...@nonvedolora.it
> www.nonvedolora.eu
> Paderno Dugnano, Milano, Italy
> 45° 34' 9'' N, 9° 9' 54'' E, UTC +1 (DST +2)
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
---
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Re: Frank King

[Dan-George Uza]

Here's the link.

https://www.dailymail.co.uk/news/article-6727419/Top-sundial-expert-sheds-fascinating-light-art-form-fears-slipping-shadows.html

Dan Uza

On Thu, Feb 21, 2019 at 11:17 AM Colin Davis 
wrote:

> Hi!
>
> In todays Daily Mail is a full page article by Frank King on his fear
> about the demise of the sundial
>
> Cheers
>
> Colin Davis
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
---
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Accuracy of wristwatch as compass

[Dan-George Uza]

Hello!

I'm sure you know the method of pointing the analogue wristwach hour hand
towards the Sun and then bisecting the angle to 12 o'clock in order to find
south (or north, if you live down in the south). Actually I guess what you
should be doing is bisect the angle to your noon time and not necessarily
12 o'clock, but anyway. A few years ago I read an interesting seasonal
accuracy analysis of this method. I also vaguely remember the demonstration
involved Vitruvius' analemma and I'm pretty sure it was all in a book.
Thing is - I can't remember where! Can you help?

Dan Uza
---
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Re: How good is a cell phone compass

[Dan-George Uza]

I would try to use a theodolite. If you center it on the first point and
know the azimuth to a distant reference, I guess you can determine where
the second post needs to be.

Dan Uza

On Tue, Sep 11, 2018 at 10:48 PM Dan-George Uza 
wrote:

> In my experience, cellphone compasses are completely unreliable for
> dialling. Some are off by more than 20 degrees. You can quickly check the
> accuracy on Google Maps: the narrower the blue cone is, the more accurate
> results will be.
>
> Dan Uza
>
> On Tue, Sep 11, 2018 at 10:39 PM Steve Lelievre <
> steve.lelievre.can...@gmail.com> wrote:
>
>> Hi everyone,
>>
>> How good is a cell phone compass? I mean, if I have no metal nearby and
>> I have the phone set to show True North, what kind of accuracy can I
>> expect if I lay my phone flat and use the compass app?
>>
>> I'm working on a vertical west sundial for a community garden (a.k.a
>> allotment) and have a deadline of end of September to get it installed,
>> because the aim is to unveil it at the group's annual meeting.
>>
>> The dial is to be installed on two posts. I want to get the posts lined
>> up as close to north-south as I can, to make aligning the dial easier. I
>> will use adjustable bolts to fix the dial to the posts, so can I
>> compensate for the line between them being a couple of degrees off - but
>> no more than that.
>>
>> I already have one post installed and concreted in place. I had hoped to
>> use the sun's meridian shadow cast by it to give me a precise line N-S
>> for placing the second post. Unfortunately, rain has set in here and it
>> looks as if there will not be a sunny day for at least a week. I don't
>> think I can wait that long to get the second post installed; otherwise
>> I'll be short of time for the other remaining tasks. Hence my interest
>> in using my phone compass for alignment.
>>
>> Cheers,
>>
>> Steve
>>
>>
>>
>>
>>
>>
>> ---
>> https://lists.uni-koeln.de/mailman/listinfo/sundial
>>
>>
---
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Re: How good is a cell phone compass

[Dan-George Uza]

In my experience, cellphone compasses are completely unreliable for
dialling. Some are off by more than 20 degrees. You can quickly check the
accuracy on Google Maps: the narrower the blue cone is, the more accurate
results will be.

Dan Uza

On Tue, Sep 11, 2018 at 10:39 PM Steve Lelievre <
steve.lelievre.can...@gmail.com> wrote:

> Hi everyone,
>
> How good is a cell phone compass? I mean, if I have no metal nearby and
> I have the phone set to show True North, what kind of accuracy can I
> expect if I lay my phone flat and use the compass app?
>
> I'm working on a vertical west sundial for a community garden (a.k.a
> allotment) and have a deadline of end of September to get it installed,
> because the aim is to unveil it at the group's annual meeting.
>
> The dial is to be installed on two posts. I want to get the posts lined
> up as close to north-south as I can, to make aligning the dial easier. I
> will use adjustable bolts to fix the dial to the posts, so can I
> compensate for the line between them being a couple of degrees off - but
> no more than that.
>
> I already have one post installed and concreted in place. I had hoped to
> use the sun's meridian shadow cast by it to give me a precise line N-S
> for placing the second post. Unfortunately, rain has set in here and it
> looks as if there will not be a sunny day for at least a week. I don't
> think I can wait that long to get the second post installed; otherwise
> I'll be short of time for the other remaining tasks. Hence my interest
> in using my phone compass for alignment.
>
> Cheers,
>
> Steve
>
>
>
>
>
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
---
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Sundial Conference in Romania

[Dan-George Uza]

Dear all,

You are cordially invited to attend the 2018 conference of the *Romanian
Society for Cultural Astronomy*. The event will take place for two days in
*Timişoara, Romania, *on *November 16th and 17th* of this year. The
organizers have launched a call for papers in one or more of the following
topics:

1. Archaeoastronomy (astronomically aligned buildings, ancient astronomical
symbols)
2. Gnomonics (sundials, history of sundials, etc.)
3. History of astronomy (events, people, discoveries, etc.)
4. Ethnoastronomy (astronomy in current societies: symbols, myths, folklore)
5. Impact of astronomy in our society (light pollution, etc.)
6. Astronomy and education

The organizers can provide free accommodation in the University guest dorms
(subject to availability) as well as partial reimbursement of travel
expenses for Eastern European participants. Of course you may also present
your paper from a distance using Skype.

The registration fee is 10 EUR/person.

You may find more details at the link below:
https://sites.google.com/view/comunicarisrpac/home-en

If you require any other information please contact me.

Best regards,

Dan Uza
---
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UFO Secrets Of The Settle Sun Dial

[Dan-George Uza]

Hello,

Any thoughts on this book?

https://www.amazon.com/UFO-Secrets-Settle-Sun-Dial/dp/B01F9QJMVM

In Settle (England) once stood "the largest sundial in the world", but it
suddenly disappeared from the scene and from the historical records. The
author suggests that this was not just a sundial, but a portal to another
world already known to Isaac Newton. In the search for the truth about the
disappearance of the sundial, we encounter UFOs, ghosts, freemasons, and
other figures...


Dan Uza
---
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Re: A trip to Vienna

[Dan-George Uza]

Darek,

For Vienna I recommend the Freiluftplanetarium installation on a hill at
the outskirts of the city. It's sort of a modern day Stonehenge and it also
has a monumental sundial (including a qibla marker!). It is a bit difficult
to get to, but I liked it a lot. Here you have some photos:
http://cerculdestele.blogspot.com/2017/06/la-planetariu-sub-cerul-liber.html

Dan Uza

On Sun, Jul 22, 2018, 21:36 Darek Oczki  wrote:

> Hello
>
> Next weekend I will be travelling to Vienna / Bratislava.
> Do we have here anyone who could recommend some sundial-related places /
> objects / museums worth visiting, please?
>
> With sunny regards
> Darek Oczki
> 52N 21E (Warsaw, Poland)
> GNOMONIKA.pl
> Sundials of Poland
> http://gnomonika.pl
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
---
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Frank W. Cousins

[Dan-George Uza]

Not realy a biography, but rather an investigation into the life and work
of Frank W. Cousins - author of "Sundials - The Art and Science of
Gnomonics / A Simplified Approach by Means of the Equatorial Dial". Text is
German, but I guess Google Translate works well enough.

https://scilogs.spektrum.de/relativ-einfach/frank-w-cousins-amateurastronom-ingenieur-buchbesitzer/

Dan Uza
---
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Meridian line in Brussels

[Dan-George Uza]

Hello! I'm looking for information and photos about a meridian line inside
Brussels St Michel church. Rene Rohr mentions it in passing in his work
about sundials. Thank you.

Dan Uza
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Sundial Atlas

[Dan-George Uza]

Dear Fabio,

Congratulations on your impressive work! I am using Sundial Atlas to keep
track of the Romanian sundials as well as every time I go abroad to find
local sundials. I am convinced that future generations will appreciate this
extraordinary tool... provided there will still be people in the future :)

Dan Uza

On Wed, Apr 25, 2018 at 11:48 AM, fabio.sav...@nonvedolora.it <
fabio.sav...@nonvedolora.it> wrote:

> Hi all, I've some news.
>
> Sundial Atlas was born 8 years ago, on april 25th 2010, and today it has
> changed appearence.
> In the last months I have worked on a new software, renewing the graphics,
> with a new faster server, with new features and, overall, with a new
> management system as planned when started.
> Sundial Atlas is not my website but an international and public tool to
> spread gnomonics through the knowledge of the sundials so the new structure
> has a national referent for every country with an heritage of sundial.
> These referents are the real management board of Sundial Atlas and they
> all together can run the project that must survive me (I'm well but I'm
> worried about the next century :-))
>
> The new website has a guide for the users (home page, click 'Sundial
> Atlas' on the left, then click 'logo & guides').
>
> If you need any info or if you have suggestions, or you find any bugs,
> plese report them to me (my role is webmaster with Gian Casalegno for the
> Android app).
> The whole transition from the old server need some days while you will
> find www.sundialatlas.net even if you call www.sundialatlas.eu, only for
> few days, anyway nothing changes for the users calling one of the two.
>
> Enjoy it, Fabio
>
> --
> Fabio Savian
> fabio.sav...@nonvedolora.it
> www.nonvedolora.eu
> Paderno Dugnano, Milano, Italy
> 45° 34' 9'' N, 9° 9' 54'' E, UTC +1 (DST +2)
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
---
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Analemma intersection

[Dan-George Uza]

Hello,

Tomorrow the Sun will have reached the point of intersection in the
analemma 8-curve. How do you compute the exact time of intersection (i.e.
when both the hour angle and the solar declination match for two days)? And
does it have any special significance?

Dan
---
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Solar math

[Dan-George Uza]

Dear all, given the azimuth and altitude of a point in the sky, what would
be the best way of finding the dates and times during which the Sun reaches
that point? Is there any software for this?

Dan Uza
---
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Zodiac concrete slab

[Dan-George Uza]

Do you think this item is genuine? I can't make out any hour lines,
although there seem to be some kind of anchor points for a rod. Watch from
min. 11:09 onwards.

https://youtu.be/-o-70BqIxIs

Dan Uza
---
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Sundial with filtering panels

[Dan-George Uza]

Hello,

How would you go about designing such a sundial sculpture
without CAD (it was built in 1980)?

https://apod.nasa.gov/apod/ap120626.html

How precise do you think it is? And what would be the minimum required
size of the separation for light to pass the filtering panels only on
equinox days?

Thanks,

Dan Uza
---
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Re: The utility of sundials today.

[Dan-George Uza]

Meanwhile in France...

According to a recent opinion poll, the monumental sundial of Perpignan
(SOLART2) made it into the top 3 of worst/ugliest roundabouts in the
country. It's also the largest in Europe.

https://tv-programme.com/journal-de-tf1_emission/replay/la-deuxieme-place-du-plus-laid-des-ronds-points-a-ete-remportee-par-celui-de-perpignan_5a579cc92893a


Dan


On Sun, Jan 14, 2018 at 9:26 PM, Willy Leenders 
wrote:

>
> When I talk about sundials, I get the question: "What utility can sundials
> have today?"
> In order to be able to give an answer as diverse as possible, I would
> like to receive your answer to this question
>
>
> Willy Leenders
> Hasselt in Flanders (Belgium)
>
> Visit my website about the sundials in the province of Limburg (Flanders)
> with a section 'worth knowing about sundials' (mostly in Dutch):
> http://www.wijzerweb.be
>
>
>
>
>
>
>
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
>
---
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Sundial Calendar for 2018

[Dan-George Uza]

Hello,

I have prepared a calendar for 2018 containing images of Romanian sundials
and some daily astronomical information (the equation of time, the Sun's
declination angle & zodiac sign, the Moon's phase & age etc.).You may
download the English version at the link below:

https://goo.gl/FNafub

It includes a brief introduction to the Romanian calendar, such as an
explanation for the names of the days and months, the dates of national
holidays etc.

This is actually my second calendar. I did the first one last year inspired
by Fabio Savian's French Republican Calendar.

The astronomical data was generated in Sun Ephemeris, Gian Casalegno's
excellent software.

A big thanks goes to Patrick Powers who was kind enough to correct my
spelling mistakes for this English edition.

The calendar is freeware so you may of course share it.

If you want to print it out I can send you a larger and higher quality
file. It's intended for A3++ size paper (330x483mm) but I guess simple A3
will do.

Have a Happy New Year or - as we like to say in Romanian - La Multi Ani!


Dan Uza
---
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Lithuania wants to abolish DST

[Dan-George Uza]

>From the news:

https://www.euractiv.com/section/health-consumers/news/lithuania-hopes-to-kill-daylight-savings-time/

Please also note the smiling sundial in the picture.

Dan Uza
---
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Sundial books for children

[Dan-George Uza]

Hello,

I am looking for titles of sundial books for children. I particularly liked
Annos sundial pop-up book by Mitsumasa Anno. Also, I would like to know
some of your experiences in working with kids. What do you think is the
best approach to teach 10 year olds about sundials?

Regards,

Dan Uza
---
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Re: Hemicyclium correction

[Dan-George Uza]

I find the video below extremely instructive!

https://youtu.be/0hs6QqwJIhs

The sundial is marked in old temporary (or seasonal) hours. Changing them
to modern hours does not make much sense to me.

For it to become a hemicyclium I guess you just have to leave out the
unused part of the half-sphere.

Dan Uza


On Sun, Oct 22, 2017 at 2:40 PM, Patrick Powers <
patrick_pow...@compuserve.com> wrote:

> Hi Brad
>
> Further to your interest in an hemicyclium you might like to know of this
> link to the former webpages of the late Frans Maes who set out his
> instructions for *“Construction of Hemispherium”* some time ago and which
> is based on several earlier documents – all referenced.  You might find it
> useful – or at least interesting!
>
> http://www.fransmaes.nl/zonnewijzers/downloads/hemisph.htm
>
> Good luck
>
> Patrick
>
>
>
> *From:* Brad Thayer 
> *Sent:* Monday, October 16, 2017 1:48 PM
> *To:* sundial@uni-koeln.de
> *Subject:* Hemicyclium correction
>
>
> I am looking to make a hemicyclium-type sundial (half-hemisphere) in a
> metal working class.  What little I can find on them says they are
> inaccurate, without being very clear on the problem.  It appears to me the
> only issue is it needs to be tilted so that the gnomon aligns with the
> Earth’s rotation axis; thus the half-bowl faces south and the gnomon points
> south, but the end of the gnomon that attaches to the bowl points north.
> Am I missing anything?  I am also looking to use an analemma-shaped gnomon
> to cast the shadow on the bowl, and at least month lines for the solar
> elevation.  The bowl will also have a rod and bracket on the bottom to
> allow it to be rotated for daylight-savings time and for local longitude
> corrections.
>
>
>
> Thanks in advance -- Brad
>
> --
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
>
---
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Re: Great Circle Studios webpage gone?

[Dan-George Uza]

I use Gian's *Sun Ephemeris* and love it!
http://www.sundials.eu/download/SunEphemeris_enu.html

Dan

On Thu, Oct 12, 2017 at 10:53 PM, Patrick Powers <
patrick_pow...@compuserve.com> wrote:

> I believe that Great Circle is indeed no longer available.  It disappeared
> once before only to return some time later so maybe there is some hope?
>
> In the meantime there is another, broadly similar resource which is at
> ​​
> http://midcdmz.nrel.gov/solpos/spa.html
>
> Anybody know others?
>
> Patrick
>
> *From:* Thibaud Taudin Chabot 
> *Sent:* Thursday, October 12, 2017 8:37 PM
> *To:* sundial@uni-koeln.de
> *Subject:* Re: Great Circle Studios webpage gone?
>
> I google with your text "Great Circle Studio's solar data calculator" and
> find:
>   http://www.redrok.com/solcalcjava1.htm
> I guess that is the page you want.
> Thibaud
>
> At 20:43 12-10-2017, Steve Lelievre wrote:
>
> I've tried to access the Great Circle Studio's solar data calculator a
> couple of time recently, but the website seems to be unavailable. Can
> anyone tell me if it's permanently gone, as opposed to suffering a
> temporary problem?
>
> I'll miss it if it is gone... it is/was a great site for getting solar
> position and EoT data.
>
> Steve
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
> --
> Th. Taudin Chabot, . tcha...@dds.nl
>
>
>
> --
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
>
---
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Sundials in Belgrade / Novi Sad

[Dan-George Uza]

Hello,

I will be travelling to Belgrade and Novi Sad next week. Can you recommend
a few sundials for me to visit there? Haven't found any on Sundial Atlas.

Thanks

Dan Uza
---
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Pocket sundial

[Dan-George Uza]

Hello, has anyone got one of those?

https://www.pocket-sundial.com/


Dan-George
---
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Adjustable metal frame for a vertical sundial

[Dan-George Uza]

Hello,

I was wondering if some of you used adjustable metal frames for orienting
vertical sundials due south. I remember seeing on the Internet such a
framework for fine-tuning vertical sundials made of aluminum composite...
but I can't remember where. Would it be possible to apply this technique to
heavier, stone plate vertical sundials? If the wall declination is no
longer an issue, I guess one can design direct south dials and orient them
properly by the watch using a rotating metal frame.

Dan Uza
---
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Re: St. Hildevert

[Dan-George Uza]

Is this an official Catholic saint? Can't find him here for today

http://catholicsaints.info/27-may/


Dan



On Sat, May 27, 2017 at 4:04 PM, Fred Sawyer  wrote:

> Happy St. Hildevert's Day - patron saint of dialists.
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
>
---
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Cast resin sundial

[Dan-George Uza]

Hello!

I'm looking for advice on how to cast a sundial from epoxy resins,
specifically a cubical multiple sundial. Any ideas on how to go about
casting the faces?

Thanks,

Dan Uza
---
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Solar watchface for a Pebble smartwatch

[Dan-George Uza]

Hello,

I've recently bought a Pebble smartwatch and I thought I'd share my
favorite watchface with you.

It's called "Solar watch". It displays the current date, outside
temperature, standard time (in white), but also sunrise and sunset times,
as well as local apparent solar time (in black). The hour hand shows the
Sun's daily progress on a 24 h circular dial featuring solar hours. Civil,
nautical and astronomical twilight markers are also present. What I like
most about the Pebble is its retro/toy-ish look and above average battery
life although the screen stays always on and is very easy to read in the
sun.

Greetings,

Dan Uza
---
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Re: Bringing the sun indoors

[Dan-George Uza]

Thanks for the link! Here's bringing the sun outdoors: if you haven't
already, check out Viganella in Italy!

http://m.dw.com/en/lighting-up-a-shady-village/av-37251098?maca=en-Facebook-sharing

Dan Uza

On 21 Mar 2017 19:29, "John Goodman"  wrote:

> Not a sundial, but another tool sensitive to solar movement.
>
> The first of her kind, Caia illuminates your home with real sunlight.
> She’s a smart robot that finds and redirects natural light for you. Caia
> remembers where to send the sunlight and keeps it there all day as the sun
> moves. You can place Caia anywhere with no installation and she will
> brighten up your home or office with sunshine.
>
>
> https://www.indiegogo.com/projects/caia-a-robot-that-
> fills-your-home-with-sunshine-solar#/
>
> ---
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>
>
>
---
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Watches that display EoT

[Dan-George Uza]

Hello,

Here's an interesting wristwatch from this year that shows the Equation of
Time in a clever way. "Sex on a wrist!" - to quote a comment.

https://www.hodinkee.com/articles/vacheron-constantin-les-cabinotiers-celestia-astronomical-grand-complication-introducing

Of course there are many more in this category, all rather untouchable
because of the price. But could there be one for us mortals? Made in China,
perhaps? I suppose smartwatch faces already exist for this. But would it be
difficult to design a mechanical EoT timepiece?

Dan Uza
---
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Re: Sun path polar chart generator

[Dan-George Uza]

Something like this.


​

Dan Uza

On Mon, Feb 27, 2017 at 8:40 PM, Helmut Haase <helmut.ha...@teleos-web.de>
wrote:

> Hell Dan-George,
> Could you post an example graph how the plot should approximately look
> like?
>
> Regards
> Helmut Haase
>
> --
> Am 27.02.2017 15:49, schrieb Dan-George Uza:
>
> Hello,
>
> I'm looking for a freeware solution to generate customizable polar sun
> path charts in vector format. The software should be able to display sun
> paths for a custom time interval (like daily, weekly) and feature analemma
> curves for standard hours. Any help will be appreciated!
>
> Dan Uza
>
>
> ---https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
>
---
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Sun path polar chart generator

[Dan-George Uza]

Hello,

I'm looking for a freeware solution to generate customizable polar sun path
charts in vector format. The software should be able to display sun paths
for a custom time interval (like daily, weekly) and feature analemma curves
for standard hours. Any help will be appreciated!

Dan Uza
---
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A different sort of timekeeping

[Dan-George Uza]

Dear group,

Here's an interesting trivia from a German book written by Helga Pohl: "Wenn
dein Schatten sechzehn Fuss misst, Berenike" (1955).

While talking about ancient Chinese timekeeping, she mentions that they
used water clocks and the shadows of the edges of their homes to tell
approximate time. However... an entirely different approach involved
looking into the eyes of cats, a practice that is also shown to be used in
20th century Switzerland in a slightly modified form: in the area around
Graubunden, shepherds tell time by looking into the eyes of their goats. I
am completely at a loss about how this could possibly work!


Dan Uza
---
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Genuine or not?

[Dan-George Uza]

Hello!

There's a diptych sundial on sale for about 80 euros supposedly dating from
1920.

Do you think this is genuine? I think it is a modern replica.

http://anticariatulnou.ro/diverse/antichitati-artizanat-colectionabile/cadran-solar-cu-busola-antica-din-lemn-diptic.html

The string does not seem to be adjustable for latitude, I see only one hole
(it's fixed at 42 deg.). Why then go through the trouble of printing the
latitudes for European cities on the back?

One thing I find interesting is the plumb bob and the orifice on the
vertical plate. I think it is meant to align the piece to the vertical. I
haven't seen this before.

Thanks,

Dan Uza
Romania
---
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British artist accuses Shanghai sundial of being ‘complete copy’

[Dan-George Uza]

Well, at least they changed the angle...

http://m.scmp.com/news/china/society/article/2050104/british-artist-accuses-shanghai-sundial-being-complete-copy-her

Dan Uza
Romania
---
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Why we should reform the Calendar

[Dan-George Uza]

A bit off topic, but I enjoyed this quite a lot!

https://youtu.be/EcMTHr3TqA0

Dan
---
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Astrolabes

[Dan-George Uza]

Dear group,

While visiting the Barcelona CosmoCaixa this spring I saw a wonderful
looking astrolabe on display in the science museum gift shop.

It is the one listed below:

http://www.antiquus.es/p-172/Orientacion-y-Medida/Astrolabio/Astrolabio-Arsenius-20-(dos-latitudes)

This brass plated astrolabe measures 20 cm / almost 8" and it comes with
two base plates for two different latitudes (41 and 45 degrees).

I was very tempted to buy it but after doing some research back home I
found that there are some inaccuracies in the rete and alidade design. They
are pointed out in the link below (in Spanish).

http://www.oagarraf.net/Comunicacions/ASTROLABI/INDEX%20ASTROLABI.html

Can you sugest other working astrolabes in this price range?


Dan Uza
---
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Permanent DST

[Dan-George Uza]

Dear group,

We are witnessing a few interesting developments! After Turkey decided a
few months ago to remain on Daylight Saving Time all year round, Hungary is
now considering to do the same.

http://www.seattletimes.com/nation-world/hungary-mulls-staying-on-daylight-saving-time-all-year-round/

If the measure passes, neighboring countries Hungary and Romania will share
the same official time for half of the year although they are located in
different time zones (CET and EET respectively). For eastern Hungary the
sun sets at about 15:40 during winter, i.e more than an hour ahead of
Paris, which shares its time zone.

I'm wondering: aren't EU member states supposed to equally follow DST by
law?


Dan Uza
---
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Solar Declination

[Dan-George Uza]

Hello,

Can you provide a free accurate spreadsheet for the calculation of daily
solar declination across a leap year as well as non-leap year?

Thanks,

Dan Uza
---
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I count only the bright hours

[Dan-George Uza]

Hello,

I was wondering about the origin of this famous sundial motto. Latin form
is *Horas non numero nisi serenas - *does this mean it's from an ancient
text? I have seen Horace's Odes quoted for this, but I haven't been able to
find it in his works.

Dan Uza
---
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The Brightest Part of a Shadow is in the Middle

[Dan-George Uza]

Hello, what a fascinating video this is!

https://www.youtube.com/watch?v=y9c8oZ49pFc


Dan Uza
---
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Using color temperature to determine time

[Dan-George Uza]

Hello!

I've recently become interested in film photography. I think it has some
similarities to sundials. For example, it is said that black and white film
photography is about taking pictures not of actual subjects, but of light
and shadows. I find it fascinating how light actually darkens the salts on
the photographic material, like a gnomon does to the surface of a sundial.
Not to mention the meridian lines in churches that also act like giant
camera obscuras, projecting the solar disc image onto the pavement.

Now I've read that daylight color temperature fluctuates by the hour of the
day: light in the early morning and late evening has under 5000 K, while
around noon it reaches 6000 K and beyond . But can you actually use this
intrinsic light quality for time telling i.e. design a color temperature
sundial?

Dan Uza
Romania
---
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Tower of the Winds

[Dan-George Uza]

Did you know that this important Greek monument has recently re-opened to
the public for the first time in 200 years?

http://www.reuters.com/article/us-greece-archaeology-towerofwinds-idUSKCN1101OS

Dan Uza
---
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Astronomical tourism in Rome, Italy

[Dan-George Uza]

Hello!

S.T.A.R by Mobile Soft is a nice phone app for your next visit to Rome. It
features several sundial-related locations inside the city. They include
the Horologium Augusti, Santa Maria degli Angeli meridian line, the
Pantheon, St.Peter's meridian line. Descriptive text is in English, but
audio-guide is only in Italian.
Of course you can always use Sundial Atlas to discover more.


Dan Uza
---
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Ceahlau shadow pyramid

[Dan-George Uza]

Hello!

You might not know about this.

Every year around the 6th of August (Feast of the Transfiguration) an
interesting optical phenomenon occurs in Ceahlau Mountains of Eastern
Romania: from the top of Toaca summit (1904 meters) a giant triangular
shadow can be seen stretching across the landscape at sunrise. It is
actually made up of at least 4 distinct shadows projected by various nearby
mountain peaks.

You can find photos and more detalis in the article below (try Google
Translate).

http://adevarul.ro/locale/piatra-neamt/foto-video-piramida-spatiala-muntele-ceahlau-fenomenul-ziua-schimbarii-fata-1_51ff94cac7b855ff56a8daf8/index.html

Unfortunately I have not seen it myself (perhaps I can make it next
year). One needs to climb the mountain very early in the morning or sleep
up there in a tent.

However, such a shadow phenomenon is by no means unique. So far I have read
about one in the Alps (
http://www.dailymail.co.uk/news/article-2209467/Phantom-mountain-Magical-pictures-conjures-spectacular-illusion-shadowy-peak.html)
and one in Tenerife (
http://gizmodo.com/5818097/the-mystery-of-the-phantom-pyramid-that-never-existed
).

Regards,

Dan Uza
Romania
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Moon phases on a meridian line

[Dan-George Uza]

Greetings!

Can anyone please share a photo of a lunar projection from a *camera
obscura* type sundial?  Thanks!

Dan Uza
---
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Re: Using analemmatic sundials for determining sun exposure times

[Dan-George Uza]

How about any south facing wall during equinoxes?

Dan


On Tue, Jun 14, 2016 at 6:39 PM, Frank King  wrote:

> Dear Willy and Geoff,
>
> Good answers but the correct value
> exceeds both your scores.
>
> Let's see who else will rise to the
> challenge before I declare my hand!
>
> Frank
>
> ---
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>
>
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Using analemmatic sundials for determining sun exposure times

[Dan-George Uza]

Hello!

An interesting use for an analemmatic sundial which I have only recently
read about involves measuring how many hours the sun potentially shines on
a given vertical wall. First you draw the analemmatic sundial on paper
according to your geographic location. Then you place a ruler on the
particular spot of the date line you are interested in. Then you rotate the
ruler around that point by the measured declination of your wall. The ends
of the ruler give you the first and last hours of wall illumination,
provided the sun is still over the horizon (sunrise and sunset times have
to be considered).

Also, if you stretch your arms 180 degrees apart pointing one arm to the
sunrise/sunset time for that particular date, the other arm will show you
the direction of sunrise/sunset.

These are from Heinz Schumacher's book "Sonnenuhren vol. 1".

Regards,

Dan Uza
---
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Sundial in Risen movie

[Dan-George Uza]

Hello,

I've spotted a horizontal sundial in the new biblical drama film Risen
(2016). You can see it in different scenes starting about half an hour into
the movie. It's alongside a hourglass on a desk belonging to Roman tribune
Clavius, the main character. I'm attaching a screenshot.

Dan Uza
---
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Planispheric projections

[Dan-George Uza]

Hello!

This is not particularly sundial-related but: can you create an oblique
azimuthal equidistant projection solely by technical drawing in Delta Cad?
I understand that David Chandler's planisphere uses such a projection in
both southern and northern face and it looks great.

http://www.davidchandler.com/products/planispheres-star-charts/

While I am familiar to the stereographic projection used for the climates
of astrolabes, I have no idea how to go about on creating an oblique
azimuthal for generating the horizon line in a planisfere such as
Chandler's. Polar equal azimuthal for the starmap seems fairly easy to do.

I would appreciate it if you can help while keeping math to a minimum :)

Dan Uza
---
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Sundials with Greek alphabetical numerals

[Dan-George Uza]

Hello!

This is the only sundial with Greek alphabetical numbering I've come across
in Romania and I was wondering: are they common in the rest of Europe?

Dan Uza
---
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Gnomon of Saint-Sulpice

[Dan-George Uza]

Hello,

Last week I visited the meridian line of Saint-Sulpice in Paris which dates
back to 1743. After the French Revolution the Republicans chiseled out all
references to royalty from the inscriptions. I don't know why but they also
erased some of the zodiac signs. Could it have something to do with the new
Republican Calendar? Also, there are two holes for the light to enter with
two spots forming on the ground and I don't understand exactly why...

Dan Uza
---
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Horary machine

[Dan-George Uza]

Hello!

An old print depicting a "horary machine" is being sold on E-bay. Can you
please tell me what it is and how it works?

[image: Inline image 2]

http://www.ebay.com/itm/1766-PLUCHE-Horary-Machine-Ring-Dial-Sundial-Antique-Engraving-/291691633308?hash=item43ea2d1a9c:g:9nUAAOxyrrpTgZSe

Thanks!

Dan
---
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Shadow during solar eclipse

[Dan-George Uza]

Hello,

A friend came up with a theory about the sundial of Ahaz. He says that
because the Moon covers the Sun from west to east during a solar eclipse,
on a very precise sundial the shadow should appear to move slightly
backwards. I've done a test using my phone's flashlight and it appears to
check out. What do you think?

Dan Uza
---
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Diamond Fuji

[Dan-George Uza]

Hello,

I saw a news report today about “Diamond Fuji”. When the sun appears to
rise or set on top of Mount Fuji in Japan it shines like a diamond.

http://newsonjapan.com/html/newsdesk/article/114827.php

-- 
Dan
​ Uza
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Re: How to tilt circular text in Delta Cad

[Dan-George Uza]

In order to get the slanted effect for the hours I used a Python based
graphics package called Nodebox and Kevin Karney's excellent script found
below.

https://www.nodebox.net/code/index.php/Sundial

Unfortunately the software only works under Mac OS, so I first needed to
set up a Virtual Machine on my Windows PC. It runs slowly but it does what
it's supposed to do and the sundial furniture is simply amazing. I save the
output as PDF, then open it in Adobe Illustrator in Windows, save it again
as DXF and finally import it into Delta Cad. However, there are a some
important artifacts which I still need to remedy manually (example: circles
are ovalised). I guess this great code could also be adapted to Delta Cad,
but I lack the ability to do so.

Thanks again!

Dan Uza

On Mon, Dec 21, 2015 at 3:04 AM, Peter Mayer <peter.ma...@adelaide.edu.au>
wrote:

> Hi Dan,
>
> It's certainly possible to wrap text in a circle.  Here's a small
> image of a modification I made some time ago to a Steve Lelievre dial.  I
> can send the bits of code I used if it's of use.  Slanting is another
> question though...
>
> best wishes,
>
> Peter
>
> On 21/12/2015 9:13 AM, Dan-George Uza wrote:
>
> Hello,
>
> This is something I've always wanted to do but didn't know how.
> I'm talking about adjusting the numerals on a horizontal sundial so that
> they appear both circular and slanted in accordance to the offset hour
> lines. Can this be accomplished in Delta Cad?
>
> Thanks!
>
> Dan Uza
>
>
> ---https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
>
> <https://www.avast.com/sig-email?utm_medium=email_source=link_campaign=sig-email_content=emailclient>
>  This
> email has been sent from a virus-free computer protected by Avast.
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>



-- 
Dan-George Uza
http://cerculdestele.blogspot.com
---
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How to tilt circular text in Delta Cad

[Dan-George Uza]

Hello,

This is something I've always wanted to do but didn't know how.
I'm talking about adjusting the numerals on a horizontal sundial so that
they appear both circular and slanted in accordance to the offset hour
lines. Can this be accomplished in Delta Cad?

Thanks!

Dan Uza
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Gnomon filaris mystery

[Dan-George Uza]

One more interesting titbit regarding filar gnomons: in 1968 Romanian-born
German-language poet Paul Celan published the poem "Fadensonnen" which you
can listen to at the link below as read aloud by its author:

https://www.youtube.com/watch?v=tV_7AVKyBpo

The English translation of "Threadsuns" goes like this:

*Threadsuns*
*over the grayblack wasteness.*
*A tree-*
*high thought*
*strikes the light-tone: there are*
*still songs to sing beyond*
*humankind*

Some literary critics think that the word "Fadensonne" is an old synonym
for "filar gnomon", certainly making this one of the strangest sundial
poems I've come across.

Dan Uza


On Sun, Nov 29, 2015 at 7:55 PM, Dan-George Uza <cerculdest...@gmail.com>
wrote:

> Hello,
>
> Catholic bishop Batthyany Ignac established one of the first astronomical
> observatories of Transylvania in Alba Iulia in the late 1700s, with
> Antonius Martonfi - a former Jesuit - serving as astronomer and director.
> The latter published a 400 page book in 1798 entitled "Initia astronomica"
> which lists the observatory's available technical equipments. Among them
> were two scientific gnomons, one of which is said to have been filar
> (gnomon filaris, gnomon filair, meridienne filaire). Today Martonfi's book
> is rather difficult to come by, there once was a copy in Cluj University
> library, but that has since vanished (perhaps it was stolen and sold off to
> collectors). So far I have been unable to gain access inside the
> Observatory in Alba Iulia and actually see what remains of these gnomons,
> but I managed to obtain a photo showing what appears to be a trap door on
> the wooden floor of the observing room, presumably with a cable running
> underneath up to the wall in the back, ending with a suspended weight (see
> enclosed). I've done some research and it seems this kind of sundial was
> first described by German physicist Christian Gottlieb Kratzenstein in
> 1782. A detailed description and drawing are also available in the work
> "Beschreibung der meteorologischen Instrumente" by Augustin Stark, a copy
> of which can be read here:
> http://www.e-rara.ch/zut/content/titleinfo/6013342
>
> Have a look at the drawing on the left of Tab. V on page 100. There light
> enters through a 2 mm hole drilled in a metal plate which is fixed outside
> the southern window, parallel to the equator, and the meridian cable runs
> across the roof of the room and also ends in a weight. From it you had to
> suspend one or more vertical wires, the shadows of which caught on a piece
> of paper were used to time solar transits. But contrary to the filar gnomon
> presented in this book, the meridian cable from the old observatory in Alba
> Iulia appears to run UNDER the floor so I am unsure how it was used. The
> question also arises whether there still are any similar working filar
> gnomons left in other old astronomical observatories.
>
> Dan Uza
>



-- 
Dan-George Uza
http://cerculdestele.blogspot.com
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: largest sundial

[Dan-George Uza]

He or she should hurry, seems there are already plans to transform the
Berlin Fernsehturm into a giant sundial (368 m) by marking the hours on
surrounding buildings.

http://www.sonnenuhr-berlin.com/

Dan Uza

On Tue, Oct 27, 2015 at 12:33 PM, Jackie Jones <jac...@waitrose.com> wrote:

> Can someone please tell me what is the world’s largest sundial?   If a
> vertical tower, how high above the ground is the nodus?  I have been
> consulted by someone who is claiming that a tower he wants to use as a
> sundial, which is 162m tall, will be the world’s largest dial.  There are
> many issues with a dial of this size, which will be explained to him, but I
> would like to know about sizes of other large dials, please.  This is not
> just a tall building casting a shadow, but one where there are hour
> markings on the ground.
>
>
>
> With best wishes to you all,
>
> Jackie
>
>
>
> Jackie Jones
>
> 50° 50’ 09” N0° 07’ 40” W
>
>
>
> -------
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
>


-- 
Dan-George Uza
http://cerculdestele.blogspot.com
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: How wrong is your time zone: Map shows how far world clocks are from solar time

[Dan-George Uza]

Here is the updated version from February 2015.

http://blog.poormansmath.net/the-time-it-takes-to-change-the-time/

Dan Uza
Pe 25.10.2015 03:10, "Donald Christensen" <dchristensen...@gmail.com> a
scris:

> I love that time zone map! does anyone know where I can download the jpeg
> file?
>
>
> Cheers
> Donald Christensen
> 0423 102 090
> www.fotoresumes.com   <http://www.fotoresumes.com>
>
>
>
> This e-mail is privileged and confidential. If you are not the intended
> recipient please delete the message and notify the sender. Un-authorized
> use of this email is subject to penalty of law.
> So there!
>
>
>
> On Sun, Oct 25, 2015 at 9:22 AM, Steve Lelievre <
> steve.lelievre.can...@gmail.com> wrote:
>
>> On 24/10/2015 15:22, Dan-George Uza wrote:
>>
>>>
>>>
>>> http://www.slate.com/blogs/the_world_/2014/02/21/how_wrong_is_your_time_zone_map_shows_how_far_ahead_or_behind_the_world.html
>>>
>>> Are you aware of any territories following official solar time?
>>>
>>>
>>>
>> Interesting question for which I do not know a definite answer, but I
>> guess it would depend on how wide the territory is. If true solar time was
>> used, then the West of the territory is going to run a different time to
>> the East. Perhaps you could standardise country wide by using, uh, a time
>> zone centred on your capital city. Greenwich to Trafalgar Square isn't very
>> far so can we treat the UK as using a timezone based on noon in its
>> capital? Not during Daylight Savings, though. As well, from the map you
>> cited, Guyana look like it's fairly well centred to its natural noon.
>>
>> For genuine local solar time, I'd like to think that there are indiginous
>> peoples left in some parts of the world who don't need to live by the
>> clock, rising with the dawn and bedding down with dusk.
>>
>> Steve
>>
>> ---
>> https://lists.uni-koeln.de/mailman/listinfo/sundial
>>
>>
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
>
---
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How wrong is your time zone: Map shows how far world clocks are from solar time

[Dan-George Uza]

http://www.slate.com/blogs/the_world_/2014/02/21/how_wrong_is_your_time_zone_map_shows_how_far_ahead_or_behind_the_world.html

Are you aware of any territories following official solar time?

Dan Uza
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Ancient sundials in Romania

[Dan-George Uza]

Dear Group,

Below you will find two articles dating back from 1966 and 1970
respectively about a few ancient sundials that have been discovered in
Romania. The text was written in French.

https://www.scribd.com/doc/286134635/Sylviu-Comanescu-Contribution-a-l-Etude-Des-Cadrans-Solaires-Antiques-Decouverts-en-Roumanie

https://www.scribd.com/doc/286135014/Constantin-Ionescu-Carligel-Contribution-a-l-Etude-Des-Cadrans-Solaires-Antiques

Those two sources are cited in some works about ancient sundials (I think
also Gibbs), but they are not easy to find.

Regards,


Dan
​ ​
Uza
---
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Re: Romanian reclining sundial

[Dan-George Uza]

Willy,

I'm sorry but I did not quite understand your message. The dial is supposed
to show standard Eastern European Time, not true local time. The longitude
correction for Bistrita is already built in the hour marks because they
were empirically drawn according to the watch when EoT was 0. Therefore the
correction table only deals with variations in Eot.

Dan

On Thu, Oct 1, 2015 at 10:55 PM, Willy Leenders <willy.leend...@telenet.be>
wrote:

> A nice project for the decoration of the roof !
> However, it is not possible to read the true local time.
> And one can not deduce it for the place at longitude: 24° 30′ 3.82′′ E
> (Bistrita) with only the table for EOTas a tool.
>
>
> Willy Leenders
> Hasselt in Flanders (Belgium)
>
> Visit my website about the sundials in the province of Limburg (Flanders)
> with a section 'worth knowing about sundials' (mostly in Dutch):
> http://www.wijzerweb.be
>
>
>
>
>
>
>
> Op 1-okt-2015, om 21:24 heeft Dan-George Uza het volgende geschreven:
>
> Dear group,
>
> I am happy to be able to share a picture of the first Romanian reclining
> sundial built recently by Damaschin Berende, a friend from a neighboring
> town. It's made of plywood, it sits on a roof and it features both a EoT
> correction table and interchangeable hour marks for winter time and
> daylight saving time. Reported accuracy is so far around 1:30 min.
> Direction of gnomon across the roof was fixed by taking a plumb bob shadow
> ​reading ​
> from the base of the gnomon at local noon, the elevation angle was
> calculated according to the latitudine and the hours were marked on the
> shadow during September 1st, when EoT was 0. I especially like the wooden
> pole etched with traditional solar motifs and the rooster on top. You can
> view more photos here:
>
> http://cerculdestele.blogspot.ro/2015/10/sine-sole-sileo-ceasul-solar-inclinat.html
>
> Please also consider it for the Sundial of the Month on
> http://sundialatlas.eu using ID no. RO23.
>
> Regards,
>
> ​Dan Uza
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
>


-- 
Dan-George Uza
http://cerculdestele.blogspot.com
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Possible sundial in movie

[Dan-George Uza]

Hello,

Tonight I saw the trailer for "The 100-Year-Old Man Who Climbed Out the
Window and Disappeared".

https://www.youtube.com/watch?v=P-k7DUQPHfQ

After the old man climbs out the window at 0:53 he walks past what appears
to be a cast iron armillary sundial. However, as the equatorial band seems
to completely circle the globe I think this piece would not show time...at
least not around the equinoxes!

Speaking about sundials in movies, I found a useful list at the link below:
http://www.shadowspro.com/en/sundials-in-movies.html

Best wishes,

Dan Uza
---
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Ancient Astronomy and Astrology in Early Judaism

[Dan-George Uza]

Hello,

This might be of interest to researchers. "Zodiac Calendars in the Dead Sea
Scrolls and Their Reception - Ancient Astronomy and Astrology in Early
Judaism" by Helen Jacobus is a recent scholarly book (2014) about ancient
middle-eastern astronomy which also handles the subject of Greco-Roman
zodiac sundials in chapter 4. The entire work seems very well documented.

You can search for it on Scribd.com

​Regards,​

​Dan Uza
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Construction of a Hemispherium

[Dan-George Uza]

Hello!

I am trying to locate a copy of Fer de Vries' website article detailing the
construction of a hemispherium sundial. The link was posted here in 1996
but it is no longer available. Please help if you can.

​Dan Uza
---
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