Re: A sundial in Seville

[Patrick Powers via sundial]

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eigentliche Nachricht steht dadurch in einem Anhang.

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Plaza de America. 
https://elsolieltemps.com/php/rutes/rutes_fitxa.php?rutes_ID=20=english

On 22/03/2024 14:41:08, Douglas Bateman via sundial  
wrote:
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Francis West and Sons

[Patrick Powers]

Members of this list who follow my 'nearly-weekly' news updates about sundials, 
dialling news and comment and related matters (it can be found at my  'SunInfo' 
webpage which is at www.ppowers.com/sun.htm) will have seen the latest entry 
about the interesting Francis West (1789–1867) sundial that was later moved to 
Frogmore House Gardens in Windsor Great Park from Claremont House in 1931 after 
its purchase by the late Queen Mary. 

Only a little is known about Francis though his business was later grown by his 
sons after his death and they expanded it into many other aspects of 
instrumentation even, it is said, to the design and sale of magic lantern 
slides!  Clearly a go-getting family.  If anyone on this list is able to add 
more either to the life and works of Francis West himself or knows more about 
his sons' follow-on businesses please do let me know.  Thank you for your help.

Patrick Powers---
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Re: Can a sundial disprove Flat Earth?

[Patrick Powers]

Hello 

Not sure about doing this with only one sundial but you can (apparently) with 
two.

See SunInfo (www.bit.ly/suninfo) look down the middle column to eight entries 
down for a light blue box entitled “Using two sundials to destroy the idea of a 
flat earth!!”

Patrick



From: Dan-George Uza 
Sent: Monday, June 17, 2019 2:04 PM
To: Sundial List 
Subject: Can a sundial disprove Flat Earth?

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



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Re: Pope Sabinian

[Patrick Powers]

Hi

I know of this which refers to him introducing the custom of ringing at 
Canonical hours and at the Eucharist – is this perhaps what you wanted?  Sorry 
I do not have the actual text. 

--
Re Pope Sabinian
See: https://www.revolvy.com/page/Pope-Sabinian

Under ‘Biography’ it says:

"The erudite Italian Augustinian Onofrio Panvinio (1529–1568), in his Epitome 
pontificum Romanorum (Venice, 1557), attributes to him the introduction of the 
custom of ringing bells at the canonical hours and the celebration of the 
Eucharist.[2]
The first attribution of this was in Guillaume Durand's thirteenth-century 
Rationale Divinorum Officiorum.[1]

Notes
1.  Wikisource-logo.svg Herbermann, Charles, ed. (1913). "Pope Sabinianus". 
Catholic Encyclopedia. New York: Robert Appleton Company.
2. Wikisource Chisholm, Hugh, ed. (1911). "Sabinianus". Encyclopædia 
Britannica. 23 (11th ed.). Cambridge University Press. p. 966.
--

Patrick







From: Darek Oczki 
Sent: Wednesday, November 07, 2018 10:26 AM
To: sundial@uni-koeln.de 
Subject: Pope Sabinian

Hello All,


We often read that Pope Sabinian (Sabinianus) edicted an order to place a 
sundial on every church. This was supposed to happen somewhen during the period 
of his reign which felt in years 604-606. Now, do we have any hard evidence of 
this statement? Any exact copy of this order, perhaps a translation from Latin? 
Was it just a single sentence eg. "You shall make a sun dyal on every church" 
or something more elaborate, with detailed instructions and explanations? 


I would be very grateful for any help.


Best regards

Darek Oczki 

52N 21E (Warsaw, Poland) 

Gnomonika.pl - Sundials of Poland 

http://gnomonika.pl





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BST/GMT

[Patrick Powers]

The history is well summarised here

http://www.bbc.com/future/story/20160310-the-builder-who-changed-how-the-world-keeps-time

From: Douglas Bateman via sundial 
Sent: Friday, August 31, 2018 4:40 PM
To: Frank King 
Cc: Sundial list 

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. 



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A missing sundial with a twist

[Patrick Powers]

Might anyone on the list have information of a dial, the engraved base of which 
can be seen in the formal gardens of the Victoria Falls Hotel, Zimbabwe at 
17.93 S, 25.84 E.  The hotel itself appears to know nothing.



The base is signed Casella London and a company of that name is still in 
existence in London yet they have no records of it in their quite extensive 
archives – indeed they are not aware of making any fixed dials at all though 
they are known for some portable dials and other scientific instruments like 
sunshine recorders. Clearly, the one in the hotel gardens is quite rare.



If interested there is more about this intriguing puzzle at www.bit.ly/suninfo. 
 



Patrick
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Another gnomon teaser?

[Patrick Powers]

Following Frank’s teaser about circular-section gnomons there are of course 
many other gnomons of varying cross sections to be seen.   Those of rectangular 
section on vertical dials have always interested me since it can often be 
difficult to know where in the shadow the time should be measured – not least 
because the answer is also affected by the time of day as well as by the 
gnomon’s shape.  See the picture for just two examples.  Has anyone ever 
devised an easy way by which to get a better estimate of the displayed time 
than the centre of the shadow in such cases?



Patrick---
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Re: Hemicyclium correction

[Patrick Powers]

Hi Brad, 

My message re your interest in hemicyclia should have made it clear that it was 
Fer De Vries’s original work on the construction of a Hemispherium that he 
placed on his website and which was republished after his death by Frans Maes 
and then placed on his own website for us to read today. My sincere apologies 
to Frans!

Patrick

From: Patrick Powers 
Sent: Sunday, October 22, 2017 12:40 PM
To: Brad Thayer ; sundial@uni-koeln.de 
Subject: Re: Hemicyclium correction

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




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Re: Hemicyclium correction

[Patrick Powers]

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




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Great Circle Studio Solar Calculator - again!

[Patrick Powers]

Hello to all those interested in the currently defunct Great Circle software. 
I have managed to make contact with the designer of the Great Circle Studio 
Solar Calculator and mentioned that it does not seem to work.  His reply 
tonight tonight is:
-
Hi Patrick,
Thank you for your e-mail. I'm afraid that got broken when I updated my server. 
I'll take a look and get it fixed.
Thanks again...

Maybe we can hope?  If I hear more I shall report it here.

Regards

Patrick
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Re: Great Circle Studios webpage gone?

[Patrick Powers]

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
  ---
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Th. Taudin Chabot, . tcha...@dds.nl







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Re: Impact of making instruments out of boxwood

[Patrick Powers]

Hi John,

Answer is I don’t know but it seems from the link below that all the different 
varieties of box known at the time in Roman times were abundant. 
If you can put up with the use of CE and BCE, see: 
https://www.ebts.org/2013/12/boxwood-in-roman-times-by-mark-v-braimbridge/
I expect that just as with oak (especially) but also with other tree varieties 
in what is now Great Britain, the old forests were simply over-harvested to 
their present state of relative rarity but that there was never any real 
‘national concern’ because there were always other sources elsewhere.  Indeed, 
by the thirteenth century it was as cheap to import oak and fir (deal) from the 
Baltic as it was to bring it from anywhere in Britain outside the home 
counties; presumably a symptom of the extraordinary demand in London as well as 
of difficulties with overland transport. 
We also need to remember that the population of England in Tudor times was only 
about 4 million, having risen from 2 million not long before, so demand for 
things made of box would surely have been quite low.   
Patrick


From: John Pickard 
Sent: Thursday, September 07, 2017 2:25 AM
To: Sundial List 
Subject: Impact of making instruments out of boxwood

Good morning,

This is purely a curiosity question.

Box wood was favoured for rules and instruments for centuries when ivory was 
either too expensive or not available for some reason. Given the number of 
rules etc. made from box wood, I would expect some contemporary concern 
about the reduction in the number of trees available.

My questions:

1. Where did all the box wood come from?
2. Was there ever a shortage?


Cheers, John

John Pickard
john.pick...@bigpond.com

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Re: a strange sundial

[Patrick Powers]

Hi Willy,
Here is another example of the reason why surrounding a dial with vertical, 
numbered, hour posts is not always a good thing!
Patrick---
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Sundials that come with 'baggage'.

[Patrick Powers]

Hello all,

It’s always interesting to look a little further into an old sundial – 
especially when it is one that is one of the lesser-known ones and is of some 
age too.  
This is true of a lovely dial set up in 1790 in Grantham, UK. [Grantham 
appeared as early as 1086 in the Domesday Book and was of course the place 
where Isaac Newton was first educated]. 

The dial of interest is a West Declining Dial which was partially ‘restored’ in 
1968 but which restoration has left a number of questions behind.

I would be interested to hear of any others’ comments about the various 
examples of restoration ‘drift’ and other oddities that are evident on this 
dial.
My initial summary about the dial can be found via a link on the SunInfo Web 
Page (www.bit.ly/suninfo) or more directly at 
http://www.ppowers.com/grantham.htm.

What might the letters ‘San’ mean?, is the motto unique in the UK? and why were 
the declination lines not restored too?, all come to mind.



Patrick Powers
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Re: Unusual bi-annual sundial

[Patrick Powers]

Hi Geoff, 

Your most interesting ‘penumbral’ comment also raises another possibility that 
this could be a tad more interesting if we can believe a ‘throw away’, and not 
fully explained, comment about the monument which suggests a question that 
there might be still more to the design than we thought.

“The ellipses of the Anthem Veterans Memorial will form a circle of light once 
a year, but we can only experience the eleventh year once in a hundred years.”

Maybe this might also be connected with the odd proliferation of the number 11 
in the engineer’s explanation?

It occurs in this link:

http://www.isisinform.com/category/memorials/anthem-veterans-memorial/

Regards

Patrick




From: Frank King 
Sent: Saturday, January 21, 2017 2:59 PM
To: Geoff Thurston 
Cc: John Goodman ; Sundial List 
Subject: Re: Unusual bi-annual sundial

Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii

Dear Geoff,

As so often, you cause me to reflect a
little and to refine my analysis...

> I wonder if the errors might be masked
> by the 32 arc minute solar penumbra.

In pondering this "instrument" I made
the naive assumption that we had an
ordinary aperture nodus.  It IS an
aperture nodus but it is hardly
ordinary...

Imagine a bug sitting at the centre
of the Great Seal and looking up the
array of elliptical openings.

We can think of the bug looking along
a tube which has a uniform elliptical
cross-section along its length.

Of course, to the bug, the far end of
the tube appears smaller than the near
end.  From photographs, I estimate
that the angular separation of the top
and bottom of the far end of the tube
is about 4 degrees or about 8 times
the diameter of the solar disc.  The
angular width is about 11 solar discs.

Although we are referring to the far
end of the tube, it is still many times
larger than the apparent diameter of
the solar disc.

The tube is therefore much too big to
be regarded as a shadow-sharpener and,
when investigating the patch of light
on the ground in the vicinity of the
Great Seal, we can deem the relevant
aperture to be the hole in the nearest
face of the shortest column.  This is
the hole closest to the Great Seal.

The only effect of the long tube is
to limit the range of declinations
and the range of hour-angles for
which the relevant aperture can give
rise to a full patch of light.

Clearly this is several days either
side of 11 November and several
minutes either side of 11:11.

When the patch of light is anywhere
near the Great Seal we can ignore
every aspect of the tube except the
nearest hole.

It is a great pity that the time lapse
video doesn't start early enough to
see just when the patch starts to
appear "full".  Otherwise I could
determine the dimensions with more
precision.

I did say at the outset that this is
a whole can of worms!

OK, that's a preliminary.  Now to
your pertinent observation...

I am sure you are right.  At 11:11
the extreme altitudes over the
10 year period are +/- 5.5 arc
minutes either side of the mean.

The fuzz at the top and bottom of
the patch of lighe illuminating the
Great Seal will always be around
+/- 16 arc minutes (half the solar
diameter) which is definitely a
greater range.

That said, the many photographs
of the spot of light at the
critical instant seem to show
the top edge of the Great Seal
not quite fully illuminated.

It is a very small effect but
it does make me wonder whether
the Great Seal has been put in
the correct place.

It would be most interesting to
see photographs on 12 November
when the declination and hence
altitude are slightly lower
and the patch would be further
out.

I think there would be a slight
over-correction and we would
conclude that the design date
of 11 November is better.

My concluding thought is that
there should be a removable
Great Seal printed on some
high-quality material and
treated with due respect.

Each year, Anthem's official
astronomer would oversee the
placing of the Great Seal
in the exact position for
the declination this time
round!

Very best wishes

Frank


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Re: Unusual bi-annual sundial

[Patrick Powers]

John,

There is also this that describes (a little) the thinking that was behind the 
way they attempted to accommodate the small changes that still occur year to 
year.

http://www.onlineatanthem.com/news/memorial-science

Patrick


From: John Goodman 
Sent: Thursday, January 19, 2017 5:01 PM
To: Frank King ; Sundial List 
Subject: Re: Unusual bi-annual sundial

Thank you, Frank. You’ve sharpened my vague suspicions with mathematical 
clarity.

> On Jan 19, 2017, at 11:33 AM, Frank King  wrote:
> 
> OK, take a deep breath and see what we are up against...

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Re: Solar Declination

[Patrick Powers]

Hi,  I have an Excel (Windows) one that is based on Smart’s formulae as 
reported by Jan Meuss.  This is simpler (!) than Meuss’s ‘better’ one but 
nevertheless it is accurate to a maximum of 4 secs and usually to within 1 sec. 
 The spreadsheet calculates all leap year days every year but in years without 
a leap year the values for the 29th Feb and 1 Mar show the same.

In 2012 I made an accurate comparison of this formula with the true one (not 
against Meuss’s higher accuracy formula) and the error curve was this:



Not sure this is what you might be looking for but if you’d like this just say.

Regards Patrick  

From: Dan-George Uza 
Sent: Tuesday, October 25, 2016 5:38 PM
To: sundial@uni-koeln.de 
Subject: Solar Declination

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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Re: Using linkages to draw curves on sundials

[Patrick Powers]

Hi John,

Would you include Nomography in such a study? 
After all nomograms might (just) be considered as mechanical devices

Patrick

From: John Pickard 
Sent: Wednesday, September 07, 2016 1:14 AM
To: Sundial List 
Subject: Using linkages to draw curves on sundials

Good morning,

While researching mechanisms of wire strainers used to tighten wires in 
fences, and trying to find the theoretical mechanical advantages of the
different mechanisms, the first thing I learned was that "linkages" are the 
key to many of them. There's a whole branch of mechanics devoted to the
theory of these things which involve a zillion combinations of pivots and 
links to achieve various purposes, usually to transmit motion in a specific
manner.

The best explanation I found was Slocum, A. (2008). Fundamentals of design. 
Topic 4. Linkages
(http://web.mit.edu/2.75/fundamentals/FUNdaMENTALs%20Book%20pdf/FUNdaMENTALs%20Topic%204.PDF).
 
3.3 MB

But my curiosity lead me further, to a more mathematical treatment. 
Unfortunately and for unknown reasons, the Jefferson Lab Library has removed 
the title page.
Bizarre! I contacted the library and they gave me the full title etc.

Svoboda, A. (1948). Computing mechanisms and linkages. MIT Radiation 
Laboratory Series, Volume 27. New York, McGraw-Hill.
(https://www.jlab.org/ir/MITSeries/V27.PDF) (CAREFUL: 40.8 MB)

Among other things, this book shows how you can use mechanical linkages of 
various forms to draw the curves of mathematical functions. And seeing that
the curves on sundials are all defined by equations, I was wondering if 
anyone knows of any attempts to make a mechanical device of links and pivots
specifically for generating sundial equations, and thus drawing sundials? It 
seems to be a feasible but complicated way of doing it, with some serious
mathematics behind the linkages.

I don't include sundial rulers in this, as they are not physically linked 
and pivotted. Similarly, I don't include CNC machining as this involves 
moving the tool / work using a pre-programmed series of x, y and z 
coordinates. And of course, 3-D printing is out.

(And I still haven't figured out what sort of linkages are used in the wire 
strainers I'm studying!)

Cheers, John

John Pickard
john.pick...@bigpond.com 

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Re unreadable dials

[Patrick Powers]

Hi Nicola

Your comment regarding the placement of armillary dials too high to be read is 
very interesting.  I am sure that you are correct.  
This practice continues (nearly) to the present day.  We have a few ‘dials’ 
like that in Britain and it does indeed seem sometimes to have been the 
practice to add focus to a garden by placing what is effectively a ‘false’ dial 
on a very tall column.

A particular one that I recall dates (I think) from the 1920s and is one which 
I managed to photograph close up some time ago. It is at Snowshill Manor in 
Gloucestershire (UK) where it is complete as a dial, even to the inclusion of a 
nodus.  It does not however have a time scale.

That dial is mounted on a 4m high octagonal column and as a consequence it is 
remarkably difficult to photograph against the sky let alone view any of its 
detail from the ground.
Thank you for providing the historical background to this interesting practice.

Patrick---
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Re: Sundials with Greek alphabetical numerals

[Patrick Powers]

Hi

That’s really interesting Dan.  I do not know of any dial in Britain/Ireland 
having Greek numerals for time indication.  However, I am aware of Greek being 
used on something like 20+ British dials but all but one of those only use 
Greek for their mottoes.  The one exception still does not use Greek time 
numerals but it does apparently have the dial’s date written in Greek; or at 
least it’s thought to be the date.  The dial was originally found in Paisley, 
which is the largest town in Renfrewshire, in Scotland but it now resides in 
England.

What is there is: 



It reads:

E. K. 
XH HHH ∆∆∆ I

Now, we have always supposed that the letters E. K. were the makers initials 
and the Greek capitals below represented the date.  However it’s not easy to 
know.  If we were dealing with ancient Greek coins (!) then their dates often 
started with an E (short for ΕΤΟΥΣ meaning ‘Of the Year’) but I don’t think 
that applies here!  The dial’s date is thought to be 1835 but I have not found 
a reference that translates what is on the dial into 1835.  Maybe this dial 
uses some sort of pseudo-Greek!

Regards

Patrick

From: Dan-George Uza 
Sent: Friday, April 15, 2016 8:50 AM
To: sundial@uni-koeln.de 
Subject: Sundials with Greek alphabetical numerals

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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Re: Painted dial

[Patrick Powers]

Hi, 

It sounds an interesting project.

If you must use wood, don’t use exterior grade ply.  Exterior grade ply 
specifications relate mainly (possibly only) to the glue that is used; not to 
the way they might survive in an exterior environment.
Marine grade ply is much better – the more so if you go for Bruynzeel Marine 
Plywood, at least 18mm thick; though it is not not cheap and may cost you over 
£200 just for your one panel.  You should choose grades that are compliant with 
either:
Suprahecht® - Lloyds register type approval certificate No. 04/00049 (E1)
Hechthout® - Lloyds register type approval certificate No. 04/00047 (E2)

They can be expected to last 10 years, possibly even 20 years.  This will 
probably be longer than the lifetime of the paint.
Always use exterior grade paints – certainly not any artistic paints, even if 
the colour range is limited and be sure to paint the back as well as the fronts 
and most importantly the sides.  Indeed it may be sensible to seal a strip of 
lead around all the edges too.

Such a dial may last 10 years or possibly more.

You might also consider using stainless steel sheet as the backing.  This can 
be powder coated and baked with its background colour before applying oil based 
paints of exterior grade or, of course – and more difficult and expensive , you 
can use a computerised approach to powder coat the dial itself on the steel 
sheet and bake that.  This would last decades. A resin coated approach might 
work too.

Regards

Patrick


From: Jackie Jones 
Sent: Friday, May 08, 2015 5:46 PM
To: sundial@uni-koeln.de 
Subject: Painted dial

Dear All,

 

I have been asked to do a painted dial for a south facing wall.  Due to lots of 
reasons, I am going to paint it on board and then screw it onto the wall when 
it is completed.  The wall is not suitable to paint directly onto and it is 
some distance away from me.  

 

I thought of using exterior or marine grade plywood; has anyone who has had any 
experience of this any tips or advice as to how to protect it so it will last a 
good number of years?  Should I also paint the back and/or cover the top edge 
of the wood?

 

Many thanks,

Jackie

 

Jackie Jones

50° 50’ 09” N0° 07’ 40” W

 




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Re: New York Times article on Flower Clocks

[Patrick Powers]

Hi Robert,

Indeed it is still using the sun!  

It’s also interesting for those of us in the UK to compare the flowers quoted 
in this article with those suggested for a similar purpose in some nineteenth 
century European gardens. There is a problem with latitude of course but an 
interesting article in a very early BSS Bulletin (Vol 91.3 p 4) suggested that 
some flowers on a sunny day in summer can (just about) be expected to open or 
close within half an hour of the same time each day.  The opening/closing times 
for the flowers suggested in that article were:

Spotted Cat’s Ear opens 6am
African Marigold opens 7am
Mouse-ear Hawkweed opens 8am
Prickly Sowthistle closes 9am
Common Nipple-wort closes 10am
Star of Bethlehem opens 11am
Passion Flower opens Noon
Childing Pink closes 1pm
Scarlet Pimpernel Closes 2pm
Hawkbit closes 2pm
Small bindweed closes 4pm
White Water Lily Closes 5pm
Evening Primrose opens 6pm

It all seems a lot of work for just a few weeks of operation, the need for a 
pond for the water lily and to say nothing of the risk from growing bind weed!

Patrick



From: Robert Terwilliger 
Sent: Thursday, January 29, 2015 11:30 AM
To: sundial@uni-koeln.de 
Subject: New York Times article on Flower Clocks

It's still using the sun to tell time isn't it?
Planting a Clock That Tracks Hours by Flowers

 

Bob




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Re: CORRECTIONS Extensions to A few new Tables for the Gnomonist...

[Patrick Powers]

Hi Kevin,
Thanks for that change.  An apparently similar problem seems to apply to the 
‘Victorian EoT’ table when Longitude is zero.  There are then listed EoT values 
of 23 and 24 mins in Jan and Feb.

You asked for input re formats on azimuth.  I think that just as with the sign 
of the EoT there are conventions that grew up with gnomonics and conventions 
that arose within astronomy and navigation.  If what you are providing is 
intended more as a resource for those interested in sundials then maybe 
Gianni’s view should prevail?
I suspect your idea of a radio button for these would be the best option!
Regards

Patrick

From: Kevin Karney 
Sent: Thursday, June 12, 2014 6:12 PM
To: Sundial 
Subject: CORRECTIONS  Extensions to A few new Tables for the Gnomonist...

Dear Friends 

Thanks for the positive comments!
And thanks to Gianni Ferrari, Patrick Powers, Edward French and Jack Aubert for 
pointing out the MAJOR error in the Annual Equation of Time Table. 
It was giving EoT values across the table instead of down, which is an error I 
had corrected before - but had crept back in!
That has been corrected Many apologies

Also, by popular request,  I have changed the sign of EoT from the strict 
astronomical convention to the more usual gnomonical convention (the correction 
to get from sundial to local mean time).

Gianni also wants Azimuth measured from the South... I am a 0 deg at North 
person. Any thoughts ? I will probably change things to give a radio button, so 
you can choose.

I have had requests for a solar noon table and solar east/west table and a 
half-minute Victorian table - which I shall implement in due course

Best wishes
Kevin



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Re: The GPS zero meridian club

[Patrick Powers]

Hi Ian,

Exactly so, and it would be interesting to see what dials there were on such a 
whole number list.  But the snag in all this though is that the definitions 
have all been changed. The arrival of satellite technology brought with it a 
global redefinition of the whole earth's ellipsoid and in 1999 the 
International Reference Meridian (IRM) was decided.  This is fixed but not 
fixed relative to a point on the earth!  It currently passes something like 
5.31 arcseconds east of Airy's meridian or 102.5 metres (336.3 feet) at the 
latitude of the Royal Observatory, Greenwich. But since 1999 and as a 
consequence of continental drift and plate tectonics, the IRM has shifted a few 
centimetres West back towards the Airy meridian. Airy will eventually be right 
(again!). That must surely be a time for REAL celebration?

In the UK WGS84 latitudes and longitudes are changing at about 2.5 cm per year 
in a north-easterly direction. In 1989, the International Reference Meridian 
passed an estimated 102.478 m to the east of the Airy Transit Circle at 
Greenwich.  There’s more about this here:

http://www.thegreenwichmeridian.org/tgm/articles.php?article=7

So, members of the ‘Zero Meridian Club’ are chasers after ephemera.  They will 
need to keep coming back every few years simply to catch up...

Patrick



From: Ian Maddocks 
Sent: Wednesday, April 30, 2014 6:14 PM
To: Douglas Bateman ; Sundial list 
Subject: RE: The GPS zero meridian club

Hi Doug

Well there's already a very similar web site
confluence.org/
This is for people trying to stand on points of exact degrees intersecting 
(according to WGS84)
I have stood on two such points   54. N  2. W  (on a lonely bit of 
moorland above Skipton, UK.It's very boggy , be careful ;-) ) and   52 N  5 
E  (Just next to a roundabout near Utrecht in the Netherlands).
Trying to think back to my browsing of the site I don't recall any dial 
connections but then most of these confluences do lie the middle of nowhere .
A more pertinent question might be what dials are on whole number lat / long 
lines (and why)

Good luck with the membership drive!

Ian Maddocks

Chester, UK



--- Original Message ---

From: Douglas Bateman douglas.bate...@btinternet.com
Sent: 30 April 2014 17:37
To: Sundial list sundial@uni-koeln.de
Subject: The GPS zero meridian club

This is a new club consisting, so far, of two members: Frank King and myself.

After the successful British Sundial Society conference, the Sunday morning was 
allocated to tours of the Greenwich Observatory. Quite independently, Frank and 
I had the intention of location the WGS84 meridian, some 90m east of the 
Greenwich brass strip.  Frank had an eTrex tracker and an app on his mobile 
phone, and I had an Axxera GPS tracker linked to my iPad.

The images, if the system will let them through, show 0º 0' 0.  Anyone else 
willing to join this new exclusive club? Plenty of places to straddle the line 
between the north pole and the south pole.

Doug (and Frank)





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Re: Sundials in (or near to) Dubai

[Patrick Powers]

Just to add some additional information about one of the dials that has already 
been mentioned.  The dial that Gianni mentions first in his response, the one 
that is in the grounds of a mosque next to Dubai Creek, was installed in or 
around 1987. It shows mean time by means of a shaped gnomon that was designed 
for the dial by Christopher Daniel. The same picture may be seen in 
Christopher’s Collection at  http://bit.ly/cstjhdaniel.

Patrick Powers

From: Gianni Ferrari 
Sent: Saturday, January 25, 2014 12:09 PM
To: Thibaud Taudin Chabot ; Len Berggren 
Cc: LISTA INGLESE 
Subject: Re: Sundials in (or near to) Dubai



Len, 
I know a single sundial in Dubai on the grounds of a mosque next to the Dubai 
Creek. 
http://www.intmath.com/blog/dubai-math-and-science/1199 

I also read the news that is being built the largest sundial in the world using 
the shadow of the Burj Khalifa skyscraper: 
http://www.flickr.com/photos/40114886 @ N05/6946793366 /

 
http://nbnl.globalwhelming.com/2010/11/25/worlds-biggest-sundial-the-burj-khalifa-dubai/
 



I also know that an Italian architect ( Arch. Paolo Ficara- Canicattini Bagni- 
Siracusa) has designed and built a large sundial for an international 
exhibition in Dubai (but I do not think it is more visible). See the article in 
The Journal of Sicily of 01.12.2013 
http://www.gds.it/gds/sezioni/vitapiaceri/dettaglio/articolo/gdsid/305695/

-- -



Thibaud, 
the general rule that you remember (a sundial in every mosque) is no longer 
followed by many years. 
Already a few centuries ago (starting from about the sixteenth century), almost 
all the sundials in the mosques were destroyed and replaced with mechanical 
clocks. 
Now from electronic billboards :-)
The same thing happened of the sundials on public buildings and churches in 
Europe. 

Fortunately, some dials have remained intact. 

Almost all are from the Ottoman period, after 1350. 
 A few dozen in Istanbul and in Turkey, very few in Cairo and in famous mosques 
in the Islamic world (Damascus, Kairouan, Tunis, etc.). 
All of these are described in my book  “Le meridiane dell’antico Islam” 

See a description of this book in 

https://dl.dropboxusercontent.com/u/6616660/ISLAMIC%20SUNDIALS_Some%20pages.pdf

https://dl.dropboxusercontent.com/u/6616660/ISLAMIC_SUNDIAL_Note.pdf



The marks of midday ( noon indicator or better indicators of the instant of the 
prayer Zhur) are very rare and, in my research which has lasted for many years, 
I found only three, all in Isfahan (Iran). 
One, that you indicate,  in the Masjid-e Shah Mosque or Mosque of the King, and 
was  built by the mathematician and poet Sheikh Baha (1547-1625), a second in 
the Friday Mosque;  a third, consisting of a rectangular stone, 75cm high, 
covered by a long inscription is in the Religious School named  Chahar Bagh 
(Four Gardens), and was built in 1932 (8 Aban 1311 HE). 

It has now been moved and no longer indicates the hour of noon. 


I never knew of sundials in Dubai, with the exception of the modern mentioned 
above.



-- -

Gianni Ferrari




2014/1/25 Thibaud Taudin Chabot tcha...@dds.nl

  In Dubai the general rule applies that in all major mosks there might be a 
sundial, sometimes an old one, sometimes a simple one that is just indicating 
noon.
  Many mosks also have what I call a 'noon indicator'. That is a stone often 
cleverly integrated in the environment which has an edge that is directly N-S. 
Result is that a side of the stone is shadow before noon and is sun lit after 
noon. Once you have seen one you recognize them easy.
  Attached one was found in the great mosk in Isfahan, Iran. (I hope the 
picture comes with this message)
  Thibaud

  At 18:56 24-1-2014, Len Berggren wrote:

Hello.
I'm going to be visiting Dubai and the region around it soon and I wonder 
if anyone knows of any sundials in that region?
-Len

-- 
J. L. Berggren
Professor Emeritus
Department of Mathematics
Simon Fraser University
 University Dr.
Burnaby, B.C. V5A 1S6
phone: 604-936-2268
fax: 604-936-2168
website: http://people.math.sfu.ca/~berggren/ 
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--
  Th. Taudin Chabot, . tcha...@dds.nl





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Re: Fwd: [HASTRO-L] Uncovering ancient Rome

[Patrick Powers]

That is excellent.  Much more believable than the shadow hypothesis (to me 
anyway) and in keeping with what a number of others say about the ‘operation’ 
of many Megalithic structures too.
Thanks for that

Patrick

From: Gianni Ferrari 
Sent: Saturday, December 21, 2013 9:17 AM
To: LISTA INGLESE 
Subject: Fwd: [HASTRO-L] Uncovering ancient Rome

Perhaps someone is interested.


Best Wishes to all
Gianni Ferrari


-- Forwarded message --
From: Clark Whelton cwhel...@verizon.net
Date: 2013/12/21



Uncovering ancient Rome

From  
http://news.indiana.edu/releases/iu/2013/12/augustus-virtual-reality-project.shtml
 :
=

Virtual archaeologist at IU turns clock back millennia to uncover
secrets of ancient Rome

NASA data, simulations used to connect Egyptian obelisk, Augustus'
'Altar of Peace'
Dec. 19, 2013

BLOOMINGTON, Ind. -- An Indiana University archaeo-informaticist has
used virtual simulations to flip the calendar back thousands of years
and show for the first time the historical significance of the unique
alignment of the sun with two monuments tied to the founder of the
Roman Empire.

For nearly a half-century, scholars had associated the relationship
between the Ara Pacis, the “Altar of Peace” dedicated in 9 BC to
then-emperor Augustus, and the Obelisk of Montecitorio -- a
71-foot-high granite obelisk Augustus brought to Rome from Egypt --
with Augustus’ Sept. 23 birthday.

Prevailing research had found that on this day, the shadow of the
obelisk -- serving as the pointer, or gnomon, of a giant sundial on
the plaza floor -- would point toward the middle of the Ara Pacis,
which the Roman Senate had commissioned to recognize the peace brought
to the Roman Empire through Augustus' military victories.

Over his nearly 40 years of teaching Roman topography classes, IU
Bloomington School of Informatics and Computing professor Bernie
Frischer had always informed students of that prevailing theory, but
today in an announcement made at the Vatican’s Pontifical
Archaeological Academy in Rome, Frischer provided another explanation
for the original placement of the two landmarks that were both
parallel and adjacent to what was at the time the major road, the Via
Flaminia, leading from Rome over the Apennine Mountains to the coast
of the Adriatic Sea.

“What's important is not the shadow of the obelisk, but the sun's disk
seen over the center of the top of the obelisk from a position on the
Via Flaminia in front of the Ara Pacis,” Frischer said. New computer
simulations now show that German scholar Edmund Buchner's longstanding
theory that the shadow of the obelisk hit the center of the facade of
the Ara Pacis was wrong.

GPS coordinates, known dimensions and additional bibliographical
sources were also used to create the 3-D models of the Ara Pacis, the
meridian and the obelisk, all of which would have been located at the
490-acre site then known as the Campus Martius. Frischer said his
Rome-based research assistant Ismini Miliaresis conducted critical
research on the meridian line location, and independent scholar and
professional meridian designer and engineer Paolo Albèri Auber
conducted the refined work on the obelisk’s original size.

Using NASA's Horizons System, which gives the position of objects in
the solar system in the sky at any time in history as seen from any
spot on earth, along with surveys of the location of the sundial’s
original meridian line, and the height of the obelisk in exacting
detail, Frischer and a team that included John Fillwalk, director of
the Institute for Digital Intermedia Arts at Ball State University,
determined the sun’s placement at the top of the obelisk occurred on
Oct. 9.

“Inscriptions on the obelisk show that Augustus explicitly dedicated
the obelisk to his favorite deity, Apollo, the Sun god,” Frischer
said. “And the most lavish new temple Augustus built, the Temple of
Palatine Apollo, was dedicated to his patron god and built right next
to Augustus’ own home.

“So the new date of the alignment, Oct. 9, is actually what we know to
be the annual birthday festival of the Temple of Palatine Apollo,” he
said. “No other date on the Roman religious calendar would have been
as appropriate as this.”

While Fillwalk and the IDIA Lab at Ball State created one interactive
model that runs in the game engine Unity, IU School of Informatics
research scientist Matthew Brennan used AutoCad and 3-D Studio Max to
create a photorealistic model the team used to generate images and
video clips illustrative of the research. Frischer then sought
independent confirmation of the findings from Lawrence Livermore
National Laboratory astrophysicist David Dearborn.

“He ran independent tests of our solar alignments, using different
software and methods, and his conclusions confirmed what we had found,
giving us added confidence that our discovery is correct,” Frischer
said.

The work is a statement to the possibilities 

Re: Dominical Letter

[Patrick Powers]

Hello John,

A bit of a side aspect to your query but the same Mr Buck was previously Vicar 
at Kirkby Malzeard and this dial seems to be from there.

See:  http://digital.library.upenn.edu/women/gatty/sundials/241.html which has, 
at entry #316, this text: 
316.FLOREAT ECCLESIA. May the Church flourish. 

This dial was given by Mr. W. Buck, minister here in anno 1697. 

This inscription is over the church porch at Kirkby Malzeard, Yorks. Mr. Buck 
afterwards became Vicar of Marton-cum-Grafton, Yorks., and put up a dial 
bearing the same motto, with his initials and date 1700, on the chancel wall of 
that Church. When the Church was rebuilt in 1873, the dial was removed to its 
present position on the vestry chimney, and the iron gnomon having been broken, 
the Rev. J. R. Lunn, then vicar, replaced it with a copper gnomon pierced with 
his initials and the Sunday Letter and Golden Number for the year of 
rebuilding. An older stone dial, possibly of the twelfth century, was found in 
the old church, and has now been inserted in the wall inside the vestry.

Gatty (1890 Ed) has slightly more about it on page 114/115 under motto #153.  

153·
FLOREAT ECCLESIA. 1697. L. 54°12'.
May the Church flourish.
Is on the church-porch at Kirkby Malzeard, Yorkshire;
and the dial is further inscribed, This dial was given by Mr. W. Buck, 
minister here in anno 1697. To be read also at Marton cum Grafton, in the same 
county.
The church of Marton was pulled down (1873), and a new one has been built. The 
dial was situated on the south side of the chancel of the original church. It 
is of stone, and is inscribed, W. B. 1700. Floreat Ecc1esia. The style
was iron and when the church was being pulled to pieces the dial fell, and the 
style was broken. The Rev. ]. R.Lunn, then vicar, replaced it with a copper 
one, solid, and pierced with 

C
XIV
IRL

giving the golden number Sunday letter and year of rebuilding. It is now 
situated on the -vestry chimney (1884).

The W.B.whose initials are on the dial was William Buck, who became vicar 1700, 
and died in 1719. He came
from Kirkby Malzeard, where he had been curate, and had erected the dial 
recorded above. Mr. Lunn states that a
much older dial of stone (without the style) Was discovered at Marton, and he 
has had it built inside the vestry amongst
other old remains. Itis possibly of twelfth century date.

Regards

Patrick
Regards

Patrick

From: John Foad 
Sent: Wednesday, November 27, 2013 3:05 PM
To: Sundial List 
Subject: Dominical Letter

The dial at Marton-cum-Grafton in North Yorkshire has a gnomon engraved with 
‘C’ and ‘xiv’, being the Sunday or Dominical Letter, and the Golden Number, for 
the year of its restoration.  I *think* that translates to 1875 (given that the 
dial is 19th century).  Can anyone confirm this?  And more interestingly, does 
anyone have a calculator to show candidate years, given the Sunday Letter and 
Golden Number?

Many thanks for any help,

John



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The Christoper Daniel Collection

[Patrick Powers]

Hello,

Members of this list will I am sure be delighted to know that BSS President and 
Britain's prolific sundial designer, Christopher Daniel MBE, has now placed on 
his new website a collection of nearly 170 photographs covering his life in 
dialling, his dials, their construction, their installation, the restoration of 
other dials and much other related material never before gathered together like 
this.

There are several other images and much descriptive text still to be added 
which those who care to come back to the site in the coming weeks will be able 
to see.

Christopher has also recently deposited his extensive archive of working 
drawings and designs - all 71 boxes of them! - with the National Watch and 
Clock Museum in Columbia PA, USA where it will shortly be available to 
researchers.

Those interested to see Christopher's website and his Collection may find it 
via a link from the popular English language Sundial Information and comment 
web site SunInfo at:

http://bit.ly/suninfo 

or directly by going to: 

http://bit.ly/cstjhdaniel 

At either of these addresses the collection may be viewed individually or as a 
slideshow.  I hope you will agree with me that the Collection forms a 
remarkable study of the life and times of a remarkable man.


Patrick Powers---
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Re: The most 'successful' sundial business - now, or in the past ?

[Patrick Powers]

Hi
I think you should avoid suggestions that one business approach might be best 
or faulted when taken across all of business.  The fact is that every system 
has faults but the ‘best’ has always to be the one where any faults can be 
identified and fixed and where the fraudulent practitioners can be brought to 
book.  My take on that is that capitalism is the only approach that has 
provided such a system over time.  Even when things go wrong (as with banks 
today across the world and here in the UK particularly) the system allows for 
corrective action.  That is the key.

I personally believe that the fundamental purpose of a business is that it 
employs people.  In the case of a very small business like a sole trader this 
might simply be a business that manages to support the owner and his/her 
family.  This implies that the business can generate sufficient ‘added value’ 
to pay a satisfactory income to the family after deduction for:
Purchase of materials/goods for resale
Rental and other maintenance costs on premises
Delivery and other transportation costs
Research and Development for the future
Advertising
Employees’ salaries, pensions, perks etc
Taxation on the business of all kinds
Any other extraordinary costs.

The same applies to a larger business.  Sometimes it may be necessary to borrow 
money in order that one might be able to build and grow the business.  In such 
a case a further cost must be that of the needed bank facility (and their 
interest charge becomes an added business expense).  Sometimes the money cannot 
be provided economically by a bank  and it might be sensible to go to the stock 
market which provides a mechanism by which others may support a financial 
investment in the business in return for part ownership.  Such people (just 
like the banks) expect to receive ‘interest’ which of course is a dividend on 
their investment.  

It is often said that the success of a (larger) business is the extent of the 
dividend that it pays to its shareholders.  That is one measure of course, but 
the REAL measure for me is the number of persons whose lives are being 
supported by the business.  Now, it would be wrong to rely on such a measure 
alone because if that was what applied to all then some businesses would not be 
deemed feasible. I think that the best measure is the number of persons who are 
being directly supported by the business (ie employees) divided by the 
turnover. That shows the extent to which the business is contributing to the 
nation’s well being.

Others will disagree but to adopt the above argument makes for some excellent 
discussion.

Sundial businesses are not really good ones to study since few people actually 
make a living from such things.  They may well (as I do) design dials as a side 
line but I would never be able to make a family business from them...

I wish your son well.

Regards

Patrick


Now, the mechanism by which a business works is that it 

PersonallyA successful business is one where

Now to answer your question!  Judging a sundial business 

From: Alison Shields 
Sent: Wednesday, July 04, 2012 4:14 PM
To: sundial@uni-koeln.de 
Subject: The most 'successful' sundial business - now, or in the past ?


Dear Sundial Mailing List Members,

It might be a very unusual question - but I would like opinions on who (or
what) the most 'successful' sundial business is, or has been, in the past.

The reason I ask, is that my son will be doing an 'A-level' school project
next term - and has chosen a subject of what actually determines a really
successful business, which I understand could be interpreted in many ways
depending on the 'points of view' of the business itself or its customers.


For example - it could be based on the 'volume' of sales, monetary 'value'
of sales, whether they are international, the types of goods/services they
provide, level of repeat orders/referrals, plus many other things as well.

I fully appreciate that there are a lot of sundial businesses out there in
the world, and each one will operate in their own unique way (depending on
their choice of 'customer-base', materials used, target market, etc) - but
I would welcome any comments, on what exactly makes a successful business.

I set no 'criteria' on what makes a really successful business - but there
have obviously been previous (and current) businesses, such as Pilkington
and Gibbs or David Harber Sundials.  Apologies, if I cannot mention you
all - but it is partly the reason for asking your opinions on the subject,
because I want to get objective and 'un-biased' details from many sources.


With my thanks, in advance, for any/all comments received in reply to this
request - but there is no hurry, so take time to think, before responding.

Once I have a few 'nominations', then I will intend to contact the various
businesses directly - to gather some additional information, as necessary.

Obviously, if any business is no longer trading - then please give me your
reasons 

Re: Sundials and tower clocks

[Patrick Powers]

Dear Darek and John

There is also Maxstoke Castle in the West Midlands (not often open to the 
public) where as I was told the horizontal dial on the front lawn was used to 
regulate the tower clock in the northernmost gatehouse tower.
Ordinary domestic clock regulation by sundials was of course very much the 
fashion in the UK in the 1700s and 1800s.  

Regards

Patrick

From: John Foad 
Sent: Sunday, May 13, 2012 9:37 AM
To: Darek Oczki ; sundial@uni-koeln.de 
Subject: Re: Sundials and tower clocks

Dear Darek,

I think there are many examples to document the use of dials to set the
clock.  One is a horizontal at the top of the church tower at Benenden in
Kent, inscribed 'This dial was given by Thos Law Hodges Esq/Anno Domini 1819
for the Regulation/of the clock in the Parish Church of / Benenden Lat 51d
3m 54s'.  Another is on a ledge of the tower at Southwell Minster in
Nottinghamshire, visible through a window from the clock chamber, but not
from the ground.  I would be interested to hear of any other examples.

In a book 'Amusing Reminiscences of Victorian Times and of Today' by a
clockmaker, John Neve Masters, we read When I was a boy in the
eighteen-fifties there were two clockmakers in Tenterden, and part of their
business was to ascertain the exact time occasionally, which in those days
was taken from sun-dials; so my father and the other 'clock-smiths' (as they
were called then) used to go to the church porch, on which was a sun-dial,
to 'take the time' .

Regards,

John

-Original Message- 
From: Darek Oczki
Sent: Sunday, May 13, 2012 9:02 AM
To: sundial@uni-koeln.de
Subject: Sundials and tower clocks

Dear Diallists

It is daid that in some point in history sundials co-existed with clocks. We
even say those sundials were used to set the right time on clocks and
personal watches. Do we have any iconographic evidence for that? There is of
course that famous drawing from Bedos de Celles (attached - Scan0237.jpg) of
a group of gentlemen setting their watches by a vertical noon dial. But I
would particularly like to find some examples of setting tower clocks. In a
book about time in general available in Poland (Ludwik Zajdler - Dzieje
zegara) there is this drawing said to be of Flemish source (attached -
Scan0236.jpg) depicting a clock master adjusting a tower clock according to
sundial readings. Does anyone know the exact source of this one, please? Are
there any other known examples?

In Europe we have many cases of public buildings having both a sundial and a
tower clock. However it seems most unlikely that these sundials were used
for setting the clocks - usually one could not see them from the clock
mechanism spot and reading it and adjusting would require two men and a
walkie-talkie :). I would rather say there had to be another, pehaps much
smaller sundial (portable?) for use of a clock master. These grand sundials
were used more as an alternative for clocks in case of some kind of
mulfunction. Any comments would be most welcome. Thank you.

-- 
Best regards
Darek Oczki
52N 21E
Warsaw, Poland

GNOMONIKA.pl
Sundials in Poland
http://gnomonika.pl





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Re: sundials and tower clocks

[Patrick Powers]

Hi Rheinhold,

Amazing. I have been to Venice several times and have never seen it.  Indeed 
this has to be as you say ‘the most visited and least noticed sundial in the 
world’!   I shall most certainly look out for it when I go again!

Thank you very much for that.

Patrick 

From: Reinhold Kriegler 
Sent: Sunday, May 13, 2012 12:39 PM
To: Sundial Mailingliste 
Subject: sundials and tower clocks

Dear Patrick Powers,

 

I also know such simple sundials to control the mechanical clocks in Spain 
(reported by Antonio Cañones) and in Italy (reported by Renzo Righi).

 

In 2005 I have published a little article at DGC-Mitteilungen magazine about 
the sundial on a column of the Basilica San Marco in Venice, which was probably 
also once used to control the famous mechanical clock nearby …

http://www.ta-dip.de/fileadmin/user_upload/bilder/8cce60c212c661239cdab2c4e1234728_Nr_101_San_Marco.pdf
 


Ciao!

Reinhold Kriegler

 

* ** ***  * ** ***

Reinhold R. Kriegler

Lat. 53° 6' 52,6 Nord; Long. 8° 53' 52,3 Ost; 48 m ü. N.N.  GMT +1 (DST +2)   
www.ta-dip.de

http://de.youtube.com/watch?v=XyCoJHwzzjUfmt=18

http://www.ta-dip.de/dies-und-das/r-e-i-n-h-o-l-d.html
http://www.ta-dip.de/dies-und-das.html

-Ursprüngliche Nachricht-
Von: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] Im 
Auftrag von Patrick Powers
Gesendet: Sonntag, 13. Mai 2012 13:07
An: John Foad; Darek Oczki; sundial@uni-koeln.de
Betreff: Re: Sundials and tower clocks

 

 

* ** ***  * ** ***

Reinhold R. Kriegler

Lat. 53° 6' 52,6 Nord; Long. 8° 53' 52,3 Ost; 48 m ü. N.N. 
GMT +1 (DST +2)  www.ta-dip.de

http://www.ta-dip.de/dies-und-das/r-e-i-n-h-o-l-d.html 
http://www.ta-dip.de/salon-der-astronomen/bewohner-des-salons-der-astronomen.html

 




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Re: Star maps

[Patrick Powers]

Here’s one to start with
http://itunes.apple.com/gb/app/goskywatch-planetarium-astronomy/id284980812?mt=8
 

It does need to be able to determine your location so make sure GPS is turned 
on or you may think it’s useless!
From: Douglas Bateman 
Sent: Monday, January 16, 2012 4:58 PM
To: sundial dial 
Subject: Star maps

A little off topic, but I asking for suggestions for simple planetarium 
software that I can load or purchase for showing the night sky. 

The reason is a planned trip in mid February to Finland at 67 degrees north 
where I hope to see the aurora or at least a starry sky, clouds permitting.

The target computer is a MacBook Air or an iPad.

I look forward to many suggestions!, 

Regards, Doug
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Re: Proceedings for Future of UTC meeting

[Patrick Powers]

the Archbishop of Sydney has made an impassioned plea for retention of BC 
/ AD, and to eschew the secular adoption of BCE / CE. I 
wonder who will win this particular ideological battle? 
He’s absolutely right of course and I hope the status quo is retained.  The 
terms CE/BCE may be understood in the US and possibly Canada too but the ‘so 
called secular’ approach simply raises confusion in the rest of the world.  I 
was a referee for the Institute of Physics for over 30 years on a specific 
topic of mass spectrometry instrumentation.  At that time that encompassed 
those instruments used for carbon dating and I well recall a 2000 year 
discrepancy that was disclosed in one paper that arose from confusion between 
stating dates as Before the Current Era and Before the Common Era. Let the 
world retain what is understood.  There is no need for change.- especially 
change that requires the entire world to be taught it consequences.
Patrick
From: John Pickard 
Sent: Friday, December 23, 2011 8:38 PM
To: Frank King 
Cc: sundial@uni-koeln.de 
Subject: Re: Proceedings for Future of UTC meeting 

Good morning Frank,

In the spirit of Christmas, I offer the following apocryphal story from 
Australia.

A British Airways pilot approaching Darwin requested a time check from the 
control tower and was informed that at the third stroke, the time will be 
twenty thirty  and thirty seconds Zulu ... beep beep beep

A pilot from a local airline made a similar request and was told six 
o'clock in the morning, welcome to Darwin

A private pilot from a remote cattle station also asked, and got the reply 
it's Saturday, mate, what are you doing out of bed so early?.

For most of us, near enough is good enough.

More seriously, it seems that a few pedants are driving this, and the Royal 
Institute of Navigation seems to have the right idea.

Happy Christmas to all who observe it, and happy holidays to others. I'm 
still not sure how happy the holiday will be here. It's been rain, rain, and 
more rain for the last few days in Sydney, and more forecast. So much for my 
planned camping trip. Oh well.

BTW, and linking time / date and Christmas: in his annual Christmas 
broadcast, the Archbishop of Sydney has made an impassioned plea for 
retention of BC / AD, and to eschew the secular adoption of BCE / CE. I 
wonder who will win this particular ideological battle?

Cheers, John

John Pickard
john.pick...@bigpond.com

- Original Message - 
From: Frank King frank.k...@cl.cam.ac.uk
To: Rob Seaman sea...@noao.edu
Cc: sundial@uni-koeln.de
Sent: Friday, December 23, 2011 11:47 PM
Subject: Re: Proceedings for Future of UTC meeting


 Dear Rob,

 No one seems to have responded to your message
 of 1 December in which you drew attention to:

 http://futureofutc.org/preprints

 Apart from the nice picture of the Prague clock
 this is rather heavy going!

 For lighter reading, I turned to the comments
 that were sent in from round the world:

 
 http://www.cacr.caltech.edu/futureofutc/preprints/18_AAS_11-668_Epilogue.pdf

 Numerous contributors familiar to readers of
 this mailing list sent in comments including:

Tony Finch
Rob Seaman
Patrick Powers
Frank King
John Davis
Christopher Daniel

 The summary showed that there were about 450
 contributors of whom 76% were in favour of
 the status quo [keeping the leap second].

 Two comments especially appealed to me:

  John Davis said:

 I (or my descendants) do not wish to have
 noon drift into the middle of the night.

  An anonymous contributor said:

 If you want a timescale with a constant
 offset from TAI, why not just use TAI?

 Many others said much the same less succinctly!

 The Royal Institute of Navigation seem to have
 been allowed the last words and say:

  In summary, making this change to UTC has a
  rather esoteric rationale, limited benefits
  and potentially significant costs.

 Unfortunately, the matter remains unresolved.

 Frank King
 Cambridge, U.K.

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Re: Sundial cartoon

[Patrick Powers]

Hi Mac,

There was this from John Carmichael to this list in 2007.  It has several on 
the same theme though I don’t think the actual one you mention.
http://www.mail-archive.com/sundial@uni-koeln.de/msg13231.html 
Patrick

From: Mac Oglesby 
Sent: Saturday, November 12, 2011 1:39 AM
To: Sundial Mailing List 
Subject: Sundial cartoon


Hello friends,

Many years ago I ran across a simple sundial cartoon which showed a 
person in bed at night checking his (or perhaps her) bedside sundial 
using a flashlight.

Extensive searching of my computers has failed to locate the drawing.

Do any of you remember the cartoon and can point me to a source? Or, 
better yet, have a copy to share?

Thanks,

Mac

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Re: BBC bans The B.C. and A.D.

[Patrick Powers]

LOL!  You misunderstand the significance of ‘guidelines’ in the BBC – which 
almost never ‘ban’ anything. Without an outcry of the sort that has now been 
precipitated (and I omitted in my original comment to add the name of the Prime 
Minister who also has been active in bringing some common sense to this 
suggestion) the effect would indeed have been to establish a ban.  However the 
real issue is less one of whether it is a ban or a suggestion, it is that such 
a silly notion can even be entertained when those for whom it is said to be 
enacted do not see any offence.  

However, let’s get back to proper forms of time, sundials!!

From: Mr. Barry Wainwright 
Sent: Thursday, October 06, 2011 7:52 AM
To: sund...@rrz.uni-koeln.de 
Subject: Re: BBC bans The B.C. and A.D.

I'm sorry, but did you even read the article you linked to? The following are 
quotes from that article...


  The guidelines suggested that the modern phrases “the common era” and 
“before the common era” should be considered as potential replacements 
[emphasis is mine]

  The corporation has insisted that there was no management directive ordering 
producers and editors across the institution to follow the secular date 
descriptions.

  The corporation has insisted that individual programmes were free to choose 
which terms were used.

  Aaqil Ahmed, the BBC's head of religion and ethics, said: The BBC, like 
most people, use BC and AD as standard terminology

  For our religion and ethics programming on BBC television and radio we 
generally use AD and BC.


There is no story here. The BBC has banned nothing. The whole issue is a frenzy 
whipped up by some headline seeking journalists, as even the most cursory 
investigation will reveal.

Unless, of course, you can point us to the wording of this BBC 'ban'...


-- 
Barry

On 5 Oct 2011, at 21:22, Patrick Powers wrote:


  John was correct to mention this and the matter is gathering pace.  See this 
from a UK broadsheet that even sees a recent Archbishop of Canterbury and now 
the Vatican as well as established BBC presenters up in arms.

  
http://www.telegraph.co.uk/culture/tvandradio/bbc/8808388/Vatican-attacks-BBCs-senseless-hypocrisy.html
 

  This silly notation is even now really only established to any degree in 
North America – though why I do not know.  For some 30 years I was a referee 
for the Institute of Physics on a minor aspect of mass spectrometry 
instrumentation, one aspect of which many will know is connected with 
instruments for conducting radiocarbon dating.  One memorable paper that I 
received for review quoted dates resulting from the stated research which were 
clearly in error from those expected, by about 2000 years.  On careful reading 
the author turned out to have used the terms BCE and CE to refer to ‘Current 
Era’ (meaning today’s dates) rather than ‘Common Era’ meaning those of AD and 
BC.  At the time of that paper there was no common understanding outside the US 
of the terms BCE and CE and there is still confusion today. It really is a 
nonsense which amounts, to quote Jane Austen’s excellent turn of phrase, to a 
‘needless precipitance’ to use such terms in science.

  Patrick

  From: Tony Finch 
  Sent: Thursday, September 29, 2011 10:43 AM
  To: John Carmichael 
  Cc: sundial@uni-koeln.de 
  Subject: Re: BBC bans The B.C. and A.D. 

  John Carmichael jlcarmich...@comcast.net wrote:
  
   Britain's BBC has banned the use of B.C and A.D. when refering to dates!

  Please don't propagate tabloid lies.
  
http://www.guardian.co.uk/politics/reality-check-with-polly-curtis/2011/sep/26/1

  Tony.
  -- 
  f.anthony.n.finch  d...@dotat.at  http://dotat.at/
  Forties, Cromarty, Forth, Tyne, Dogger: South 4 or 5. Slight or moderate.
  Mainly fair. Good, occasionally poor.
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Re: BBC bans The B.C. and A.D.

[Patrick Powers]

John was correct to mention this and the matter is gathering pace.  See this 
from a UK broadsheet that even sees a recent Archbishop of Canterbury and now 
the Vatican as well as established BBC presenters up in arms.

http://www.telegraph.co.uk/culture/tvandradio/bbc/8808388/Vatican-attacks-BBCs-senseless-hypocrisy.html
 

This silly notation is even now really only established to any degree in North 
America – though why I do not know.  For some 30 years I was a referee for the 
Institute of Physics on a minor aspect of mass spectrometry instrumentation, 
one aspect of which many will know is connected with instruments for conducting 
radiocarbon dating.  One memorable paper that I received for review quoted 
dates resulting from the stated research which were clearly in error from those 
expected, by about 2000 years.  On careful reading the author turned out to 
have used the terms BCE and CE to refer to ‘Current Era’ (meaning today’s 
dates) rather than ‘Common Era’ meaning those of AD and BC.  At the time of 
that paper there was no common understanding outside the US of the terms BCE 
and CE and there is still confusion today. It really is a nonsense which 
amounts, to quote Jane Austen’s excellent turn of phrase, to a ‘needless 
precipitance’ to use such terms in science.

Patrick

From: Tony Finch 
Sent: Thursday, September 29, 2011 10:43 AM
To: John Carmichael 
Cc: sundial@uni-koeln.de 
Subject: Re: BBC bans The B.C. and A.D. 

John Carmichael jlcarmich...@comcast.net wrote:

 Britain's BBC has banned the use of B.C and A.D. when refering to dates!

Please don't propagate tabloid lies.
http://www.guardian.co.uk/politics/reality-check-with-polly-curtis/2011/sep/26/1

Tony.
-- 
f.anthony.n.finch  d...@dotat.at  http://dotat.at/
Forties, Cromarty, Forth, Tyne, Dogger: South 4 or 5. Slight or moderate.
Mainly fair. Good, occasionally poor.
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Re: sundial read from moonlight

[Patrick Powers]

Hi Donald

I cannot help you with an article on that specific topic but there is a dial at 
Queens’ College Cambridge which has at its bottom a table of corrections to be 
used to tell time by the moon.  An article published by the University 
(courtesy Drs Robin Walker and Frank King) is at

http://www.queens.cam.ac.uk/page-241 

It describes the dial and includes mention of the table and how it should be 
used.  These corrections apply to all dials, not just to that at Queens’.  I 
hope it helps; but I have to say that when even when you do make the requested 
corrections the resulting time may still be quite inaccurate!  The moon’s 
motion is much more complicated than can be described by a few simple integers.

Patrick



From: Donald Christensen 
Sent: Sunday, July 31, 2011 1:14 AM
To: f.w.m...@rug.nl 
Cc: sundial@uni-koeln.de 
Subject: Re: sundial read from moonlight

Sorry

I wasn't very clear with my question.

I'd like to know how to read a horizontal sundial in the moonlight. I
wish I could find the artical that I read on it.

I'm going by memory so this is probably wrong but it went something like this:

On a full moon, a horizontal dial reads correct.
For each day after a full moon, 43 minutes must be addet to the time.
Likewise, for each day before a full moon, 43 minutes must be
subtracted to the time.


On 7/31/11, Frans W. Maes f.w.m...@rug.nl wrote:
 Dear Donald,

 One can use the moon's shadow as long as it is distinguishable at night,
 say, one week either side of full moon. For an example, see:
 http://www.fransmaes.nl/genk/welcome-e.htm, choose menu item 7 and
 scroll down in the right-hand frame to The moon dial.

 Best regards,
 Frans Maes

 On 30-7-2011 10:23, Donald Christensen wrote:
 I heard that a sundial will read the correct time with the shadow on
 the moon on a certain day. (full moon?)




-- 
Cheers
Donald
0423 102 090


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.
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Sundial read from moonlight

[Patrick Powers]

Hi Donald

I cannot help you with an article on that specific topic but there is a dial at 
Queens’ College Cambridge which has at its bottom a table of corrections to be 
used to tell time by the moon.  An article published by the University 
(courtesy Drs Robin Walker and Frank King) is at

http://www.queens.cam.ac.uk/page-241 

It describes the dial and includes mention of the table and how it should be 
used.  These corrections apply to all dials, not just to that at Queens’.  I 
hope it helps; but I have to say that when even when you do make the requested 
corrections the resulting time may still be quite inaccurate!  The moon’s 
motion is much more complicated than can be described by a few simple integers.

Patrick



From: Donald Christensen 
Sent: Sunday, July 31, 2011 1:14 AM
To: f.w.m...@rug.nl 
Cc: sundial@uni-koeln.de 
Subject: Re: sundial read from moonlight

Sorry

I wasn't very clear with my question.

I'd like to know how to read a horizontal sundial in the moonlight. I
wish I could find the artical that I read on it.

I'm going by memory so this is probably wrong but it went something like this:

On a full moon, a horizontal dial reads correct.
For each day after a full moon, 43 minutes must be addet to the time.
Likewise, for each day before a full moon, 43 minutes must be
subtracted to the time.


On 7/31/11, Frans W. Maes f.w.m...@rug.nl wrote:
 Dear Donald,

 One can use the moon's shadow as long as it is distinguishable at night,
 say, one week either side of full moon. For an example, see:
 http://www.fransmaes.nl/genk/welcome-e.htm, choose menu item 7 and
 scroll down in the right-hand frame to The moon dial.

 Best regards,
 Frans Maes

 On 30-7-2011 10:23, Donald Christensen wrote:
 I heard that a sundial will read the correct time with the shadow on
 the moon on a certain day. (full moon?)




-- 
Cheers
Donald
0423 102 090


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.
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Re: How to force spreadsheet to create printable graph with same scalein X and Y?

[Patrick Powers]

Hi Steve:

I don’t think there is a specific command to do that in Excel (don’t know about 
Open Office) but I understand you can do it in Excel by using VBA.  Have a look 
at this page:
http://peltiertech.com/Excel/Charts/SquareGrid.html 

Incidentally this Jon Peltier site has a wealth of other tips and tricks...

Regards

Patrick

From: Steve Lelievre 
Sent: Wednesday, June 22, 2011 12:29 AM
To: Sundial List 
Subject: How to force spreadsheet to create printable graph with same scalein X 
and Y?

Hi,

I sometimes use a spreadsheet to calculate a series of X,Y points, and 
then use these points to create a scattergram chart. My problem is that 
whenever I do this, the chart appears on the screen as a rectangle. The 
X and Y dimensions aren't to the same scale. I have to set the gridline 
intervals to be the same for X and Y and then adjust the chart so that 
the shape looks OK on screen.

My problem is that even if the chart grid appears to be in good 
proportion on the screen, it's only as good as my eyes. What I really 
want is to print an accurate diagram that I can use as an experimental 
dial. In short, I want the printed chart to be on a square grid that is 
really square.

Can anyone explain to me how to force the spreadsheet software to use 
absolute distances for a printed chart's axes? Alternatively, a way to 
force equal gridline spacing would be equally as helpful.

I use both OpenOffice and Excel - an answer for either one will be much 
appreciated.

Cheers,
Steve




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Re: 9/11 'sundial' memorial

[Patrick Powers]

Thank you Fred for alerting us all to this excellent idea.  

I for one would very much applaud the idea of a moving shadow memorial for 
those so tragically lost in NY during 9/11.  However, as with so many matters 
connected with dialling we should not be surprised to know that there are 
precedents!  I don’t know whether those on this list will recall but all of the 
Channel Islands (they are part of the British Isles, not part of the UK or of 
the EU but have the Queen as their monarch) experienced terrible privations in 
WW2 after their independence had to be sacrificed when they could no longer be 
defended by Britain.  To mark fifty years after the Islands were liberated, a 
monument was commissioned in Guernsey and BSS Member – and Guernsey resident - 
David Le Conte designed it.  It delivers a shadow that on May the 9th each year 
(Liberation day for Guernsey) moves across plaques at particular times 
recording the events of that wonderful day.  At the very end of the seating the 
words Thanks be to God are inscribed both in English and in Guernsey-French. 
The accuracy of the shadow is startling.

So far, I have never been able to be there on May the 9th (that being a family 
birthday!) but I do hope I can one day.  Even today after nearly 70 years there 
are still poignant memories held by many British people of the way in which we 
had to abandon the Channel Islands to their fate, and in memories held by those 
many Island families who suffered greatly for several years and of course in 
the united joy that came with the eventual liberation.
For those who might wish to learn more, there is more about the Guernsey 
Liberation Monument at:

http://www.astronomy.org.gg/liberation.htm 
Regards
Patrick
From: Fred Sawyer 
Sent: Wednesday, May 18, 2011 7:46 PM
To: Sundial List 
Subject: 9/11 'sundial' memorial

Maryland is planning a 9/11 memorial using the shadow of a building to
indicate the times of the various events of the tragedy.

See http://www.maryland911memorial.org/about-the-memorial/memorial-design

Fred Sawyer
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Fw: Are there any commercially-available 'Teaching Sundials', for schools ?

[Patrick Powers]

Setting aside the matter of Educational Authorities who cannot think (!), I 
also agree that you might like to give this another go in order to allow the 
Authority to think again.

There is another type of dial you might try on them – one that can also be 
painted on the ground and where the person standing on it casts the shadow in a 
similar way to an analemmatic dial.

This is the human nodus horizontal dial where the dial is a conventional 
(though large) horizontal dial and the person stands on the noon line at a 
point on a scale of heights such that the top of their head is at the same 
height as a real gnomon would be.
These are strangely rare (at least in the UK) with only a few known. John 
Moir’s one at Poplar in London is a recent example (see the blurred image 
attached – I can email a better image) and it’s hard to see how any thinking 
person could object to something like this for children.

Not only that but its operation is much easier to explain and to compare with 
conventional horizontal dials and also of course, given the solar time it can 
be used to determine the child’s height – something which they find fun.

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Re: Are there any commercially-available 'Teaching Sundials', for schools ?

[Patrick Powers]

Hello Martina,

Setting aside the matter of Educational Authorities who cannot think (!), I 
also agree that you might like to give this another go in order to allow the 
Authority to think again.

There is another type of dial you might try on them – one that can also be 
painted on the ground and where the person standing on it casts the shadow in a 
similar way to an analemmatic dial.

This is the human nodus horizontal dial where the dial is a conventional 
(though large) horizontal dial and the person stands on the noon line at a 
point on a scale of heights such that the top of their head is at the same 
height as a real gnomon would be.
These are strangely rare (at least in the UK) with only a few known. John 
Moir’s one at Poplar in London is a recent example and it’s hard to see how any 
thinking person could object to something like this for children.

Not only that but its operation is much easier to explain and to compare with 
conventional horizontal dials and also of course, given the solar time it can 
be used to determine the child’s height – something which they find fun.

If you are interested there is an image of John’s really excellent dial in 
Aberfeldy Millennium Green, Poplar, London E14 at this URL:
http://www.ppowers.com/poplar.htm 

Patrick



From: Martina Addiscott 
Sent: Friday, April 22, 2011 12:19 PM
To: sundial@uni-koeln.de 
Subject: Are there any commercially-available 'Teaching Sundials',for schools ?


Is anyone aware of a commercially-available large 'Teaching Sundial', which
would be suitable for fulfilling that part of the UK National Curriculum ?

As many of you no doubt know, sundials are included in the Science section
of that curriculum, but each school decides for themselves how to cover it.

We had originally intended to mark an interactive analemmatic dial on to
the playground - but our local Educational Authority will not give us their
permission for that, because of the 'health and safety' implications (as
basically they feel that such layouts are too dangerous for the children).

It had also been suggested to us that a large globe-of-the-world might be a
good way to cover the necessary aspects (Latitude/Longitude, daily rotation
of the earth, night/day, annual change of seasons, etc) - but we feel that
there has to be something better and more 'sundial-specific', if only we
can trace suppliers of any suitable item being sold at a reasonable price.

Len Honey at Science Replicas suggested an individual portable dial, for
each pupil - but (apart from the cost), we think that those would soon get
damaged (or simply 'go missing').  Instead, if this is possible, we would
prefer one large 'demonstration' sundial - ideally in wood or plastic (not
metal, as that would be expensive, plus too heavy for a teacher to hold).

Though Mr Honey offered to have something specially designed/manufactured
for volume sales to schools, it is likely to take some time to implement.

Hence my plea to this Mailing List - asking if there are any 'commercial
Teaching Sundials' already on the market, and if so, can anyone point me
towards the supplier of them.  We have a budget of 500 Pounds, for this.

Sincerely,

Martina Addiscott.


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Re: varying speed?

[Patrick Powers]

Well said.  Not only that but the sun wobbles too with its barycentre currently 
outside the sun’s disc. Whilst the Earth-Moon system isn’t the major 
contributor to the overall wobble of the sun it’s one of the most complicated.  
I like the link at

http://www.orbitsimulator.com/gravity/articles/ssbarycenter.html 

which well shows the effects of the different planetary influences on the sun’s 
barycentre.

Patrick

From: Kevin Karney 
Sent: Friday, March 25, 2011 8:16 PM
To: Marcelo 
Cc: Sundial List 
Subject: Re: varying speed?

Marcelo  

Nothing is constant in the heavens ! 
The 'tropical' year (from equinox to equinox) is 365.242190 days
The 'sidereal' year (fixed star to fixed star) is 365.256363 days
The 'anomalistic' year (perihelion to perihelion) is 365.259636 days - cycling 
over a period of some 21000 years
(values for 2009 from Astronomical Almanac)
But these are mean values having averaged out the effects of nutation (the 
wobbling of the Earth's axis) and various other effects.

Perihelion is even more complicated
in 2010 - 3rd January 0 hrs
in 2011 - 3rd January 19 hrs
in 2012 - 5th January 1 hrs
in 2013 - 2nd January 5 hrs
in 2014 - 4th January 12 hrs
(values from US Naval Observatory web site)

This is strange behaviour - not just a leap year effect!  I have heard that 
this is because - from the Keplerean point-of-view - the Earth and Moon rotate 
as a unit in an ellipse around the sun - like an out of balance dumbell - whose 
centre of gravity is somewhere in the Earth's core but not at its centre. So 
the actual moment when the Earth is closest to the Sun depends on the position 
of the Moon. This was explained to me some 50 years ago by my uncle who was a 
dedicated but amateur astronomer. I have never it confirmed by a professional 
astronomer.

Best regards
Kevin Karney
Freedom Cottage, Llandogo, Monmouth NP25 4TP, Wales, UK
51° 44' N 2° 41' W Zone 0
+ 44 1594 530 595



On 25 Mar 2011, at 16:14, Marcelo wrote:


  Your question brought to my mind an old doubt. 

  As the points of perihelion and aphelion are continually changing (in a very 
slowly way, but they are), so the EoT is also changing from an year to another, 
right? I mean, if a century ago perihelion and aphelion occurred not in january 
and july, but in december and june (it's only an example, I don't know how much 
time does it need to change), then the EoT was different. 


  2011/3/25 Marcelo mmanil...@gmail.com

Hello Brent, 

as long as I know, the Earth's speed really has a variation throughout the 
year, for its orbit being ellliptical, with the Sun in one of the ellipse 
focuses, it is faster when nearer to the sun (perihelion) and slower when its 
at maximum distance from it (aphelion). 

Both the perihelion and aphelion are upon the ellipse's major axis.

As a result, the sun's apparent ecliptical longitude changes a little 
slower in july than it does in january.

Further, as Earth's axis has a declination of ~ 23.5 degrees, that means 
that the Sun's apparent longitude measured upon the Equator is slightly 
different of its ecliptical longitude (measured upon the Earth's orbit plan).

So, neither is the Sun moving from West to East regulary throughout the 
year, neither is its movement on the ecliptic equal to that on the Equator - if 
Sun moves 1 degree with relation to the ecliptic, it may move 58 minutes of arc 
with relation to the celestial equator. 



2011/3/24 Brent bren...@verizon.net

  Hello again;

  I read this at:
  http://www.sundialsoc.org.uk/HDSW.htm

  Part 17
  When we look at the Sun we are observing it from a moving
  platform. It is the varying speed around its elliptical
  orbit and the tilted axis which are responsible for the
  daily variations accounted for by the Equation of Time.

  I'm confused about the varying speed part.
  Does the earth actually change speed as it travels around
  the sun or is it just the way we perceive it?

  thanks again;
  brent

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Re: bad sundials

[Patrick Powers]

Hi Brent,

The BSS Register has many ‘non-dials’ on its books. Some (though few) have 
other dialling interest. We used to record all except the most flagrantly 
erroneous one so that we could use the data for research but now are moving 
away from that because there are so many ‘garden-centre dials’ that do not 
work.  Plenty of dial designers make mistakes and it isn’t hard for the so 
called experts to do so either!  I’d always recommend that designers make a 
model out of paper or card before committing.  Not only that but if you are 
designing the dial commercially and have no professional indemnity insurance 
the submission of the working model can be used to secure acceptance of the 
design (and hence limit the risk for the designer) without the expense of 
professional insurance.

Patrick

From: Brent 
Sent: Saturday, March 12, 2011 7:39 PM
To: Sundial List 
Subject: bad sundials

Hello again;

I hope I am not trying your patience with my endless questions.

Today I am thinking about all of the mistakes that I have 
made in my thinking about sundial designs. The motions 
between the sun and earth are more complicated than I first 
thought.

I wonder if lots of people make sundial mistakes?
I wonder if there are lots of sundials around that contain 
mistakes?
I wonder if there are any famous sundial blunders?

thanks again;
brent

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Re: Where are the women?

[Patrick Powers]

Well, just doing a simple count of those who title themselves Mrs, Miss and Ms 
(That is to say ignoring those ladies who title themselves Dr and Prof, Rev 
etc) in the BSS Members list of a few months ago we have 46.  That’s about 10% 
of the membership.

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International Sundial Trail Competition

[Patrick Powers]

Why not put together a sundial trail in an area of interest known to you?

In order to increase interest in sundials generally, The British Sundial
Society and Sundials on the Internet  have come together jointly to
promote a prize for the best  sundial trail to be developed in 2009.  

This competition is open to all but the closing date is 31st January 2010,
and two prizes, of £250 and £100 are offered for the best entries
submitted.  Full details of the rules and regulations etc are to be found
at http://www.sundials.co.uk/competition2009.htm and these will shortly
also be placed on the BSS website.

Have your camera with you this summer and let us have details of your
trails...

Patrick Powers  Piers Nicholson
For and on behalf of BSS  Internetworks Ltd, who are the webmasters of
www.sundials.co.uk




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2009 EofT ON A MAC

[Patrick Powers]

Hi Tony,

Until it has to be moved (as a result of the imminent demise of Compuserve
at the end of June 2009!) you should be able to see 2009 figures via your
Browser at

http://ourworld.compuserve.com/homepages/patrick_powers/EoT.htm

I shall put them on a new hosting site soon.  I also have an Excel 
spreadsheet that uses Smart's approach as per Meeus and which can compute
the figures for any other year. Just say if you would like that.

Patrick

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Re: Baldwin Solar Chart

[Patrick Powers]

 have a request from Jürgen Giesen - who wrote the NASS Current Solar Data
Java applet.
 He is seeking information about the Baldwin Solar chart.

There is also this PDF of an article that mentions the Baldwin Solar Chart
and a simplification of it. Might it be of interest?

Patrick

http://www.vetmed.wsu.edu/org_NWS/NWSci%20journal%20articles/1950-1959/1954
%20vol%2028/v28%20p43%20Campbell.PDF

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Re: Earliest Roman Dial

[Patrick Powers]

...However, there is one dial for which I have attached a picture (32kb)
which was found at Housteads Fort on Hadrian's Wall and 
which was undoubtedly not imported

Hi Frank, Your dial might be the one I saw in a museum along Hadrian's Wall
 all those years ago - it certainly was of that form though it was then set
flush in plaster in a large square wooden frame as far as I remember.  I
must say though that it doesn't seem to be what one would ordinarily think
of as Roman.  However Gibbs reports several Graeco-Roman vertical planar
dials - indeed she has a section devoted to them,  One (Gibbs 5022G),
though apparently  undated, being in the British Museum (BM Ref: 2546)and
appearing very like this one. However without any attributed date it's hard
to say if it is Roman.  Whatever now that some parts of a water clock have
been found along the Wall no doubt they must have had some dials there at
that time even if  none have yet been found. All very puzzling.

Patrick

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.Re: Variation in Sun's declination

[Patrick Powers]

Alex wrote: !While on a search for something else, I began noticing that
values for the declination of the sun seem to vary a great deal

In using a date of September 1st  you are in a period of the year when the
declination of the sun is changing by about 21 or 22 arcminutes per day so
the time chosen on the days in question is important..  Also because of the
leap year cycle there will typically be a 5 arcminute change from year to
year at that time of year so any one quoted figure that makes no mention of
the year will also not reflect the instantaneous figure.

I suspect that the majority of the differences that you are seeing are
connected with estimates made for different times of day or are ones using
averages over four years - or both!.  If you are looking for higher
accuracy then I'd choose a calculator that permits input of both date and
time.

Regards

Patrick

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Re: Earliest Dial

[Patrick Powers]

The dial SRN0818 referred to by Patrick Powers as being a Roman dial at
the famous Vindolanda Roman site at Bardon Mill, Cumbria, close to
Hadrian's Wall,  is not a Roman dial but a more recent conventional garden
dial. 

Frank is right!  The one recorded by BSS as being near to or in Vindolanda
is not the stone one that I saw upside down in the museum some twenty years
ago.  It's true that they didn't then know it as a dial and it wasn't
recorded as that at the time.  Now after all this time I am wondering if I
have mistaken Vindolanda with Chesters.or Housesteads.  Clearly I need to
go back on a holiday!!

Patrick

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Re: Is this thing a sundial?

[Patrick Powers]

The photo caption says that it is a sundial located in the atrium in the
National Acaedmies building (in Washington). 

Interesting though it doesn't seem to be a 'real' sundial, John.  To me it
seems to be more of a coloured light show that changes as the sun tracks
across the sky.  There is a little more at: 

http://www7.nationalacademies.org/arts/Kirkland_Needle.html

where it says it is 'not a specific scientific device'

Patrick

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Re: Earliest UK Sundial

[Patrick Powers]

Can anyone tell me which is thought to be the earliest UK sundial? David
Brown Somerton, Somerset, UK

There are a number of Saxon dials in the UK (circa 50?)  though of those
the Bewcastle Cross dial might well be the earliest.  However there is a
Roman dial at the Hadrian's Wall fort of Vindolanda (SRN0818) which is now
inside in the museum - and mounted upside down incidentally!  (They have
just discovered what might be a rare Roman calendar or even part of a water
clock at Vindolanda too). 

There is another Roman dial at Hever Castle in Kent believed not to be
mentioned in Gibbs though it might be one of those that Gibbs reports as
location unknown) It is SRN 1961 and the BSS Register says of it:
Important intact Roman spherical dial with ?11 inscribed hour lines  with
oblique lower front and gnomon slot.  Two (worn) lion supporters at base
and two rosette decoration on top front.  Set upon an inscribed square
section Roman pedestal..  

Gibbs reports a few Roman dials in the UK, one (Gibbs#1018) at Ince
Blundell Hall, Lancs and of course several in the British Museum.

My guess (and it is only a guess!) for the earliest outside those in
museums would be  that at Vindolanda and that must be presumed to be in its
original location too.  Hadrian's Wall was begun in AD 122 and mostly
(amazingly!) completed in six years so we might even be brave enough to
give the Vindolanda dial that sort of date!  

Regards

Patrick

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Short of ideas for Christmas?

[Patrick Powers]

If you are short of ideas for presents at Christmas time either for
yourself or for a friend interested in dialling why not consider supporting
one of the many Sundial Societies around the world by taking out - or
getting another to give you - membership of one?  

Most societies have a web site with details of  how to join.  The British
Sundial Society will even let you send in your own gift card which they
will then send to the recipient for you along with Membership details.


Patrick

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Re: Leap second is back

[Patrick Powers]

The Leap second is back - evidently the current administration's proposal
to eliminate them has not been adopted.

Excellent news indeed for diallists and lovers of solar time but isn't it
rather sad that the link that reported this good news gets its facts wrong
- like so many others you can see relating to the leap second?  It makes
the mistake of attrbuting the need for the leap second to the slowing down
of the earth.  It is related to it of course but the slowing of the earth
is actually only circa 1.5mS per century and since atomic time was defined
to equate with solar time at 1900, now - roughly 100+ years later,  we have
a discrepancy of 1.5mS between the two time scales.  It is to adjust for
this that we need the leap second .  Indeed it is interesting to note that
even if miraculously the earth's rotation did not slow down from now on we
would still need leap seconds every few years to keep our closks in
synchronism with solar time.. 

Ah well, pedantry is a good thing sometimes

Patrick

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Re: Unknown Solar device

[Patrick Powers]

Thanks to all who have sent in observations on the device my son alerted me
to and which I showed at 

http://tinyurl.com/5gnqz6

I have been away for a week and only just got back.  Apologies therefore
for this late acknowledgement to all who responded.

The device is, as several suggested, clearly one of the folding versions of
the Wheatstone design and identical to one in the Old Royal Observatory
Greenwich. A picture of that dial is shown in Allan Mills' article in the
BSS Bulletin 98.1 Feb 1998 to which some of you kindly pointed me..

In that article Allan then goes on to describe how to make a modern
'replica' polarisation dial by using sellotape and a black perspex analyser
 but the interesting thing is that his replica shows a 180 degree time
scale divided from 6 to 6 whereas the model I showed and (as may be seen by
using a magnifying glass on the image in the BSS article), the one in the
Greenwich Observatory  too, both have a time scale of 12 to 12.

Before I have to set to and make one of these 'replicas' to discover the
truth (!), can anyone tell me if there an explanation for this difference
between the two designs? 

Regards  Patrick

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'Folded' Gnomon Declining dials?

[Patrick Powers]

There is an unusual East Declining Vertical Dial on the side of the
Cathedral (Catedral de Santa María de la Sede) in Seville (Sevilla) in
Spain.  

It has a gnomon which is 'folded' from the Noon line rather than being
placed orthogonal to the dial plate along the sub-style line as is more
usual,. This dial must decline by around 50 degrees to the East.

As far as I know there is only one dial of similar construction here in the
UK (it is SRN 1279 in Hertfordshire) - though there may be others - and as
a consequence this form of construction has in Britain at least, been seen
as a rather 'amateurish' form of design.  

However having found this dial in Seville the question arises:  Is this
form of gnomon construction more common than I thought?  Are there more
instances of this form of gnomon design elsewhere and have they been
produced by what nowadays would be regarded as 'professional' designers?

The Seville dial and the one known in the UK may be seen at 

http://tinyurl.com/4x24my

Many thanks for any comments

Patrick




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Re: Mac sundial design program

[Patrick Powers]

I'm forwarding this for Roger Bourke.  I know the question has come up
before.  Perhaps a listmember who is familiar with Macs can respond to
him offline.  Thanks.

I'm responding to Roger off line as suggested but perhaps others with Macs
( I do not have one)  might be able to run the general spreadsheet or one
of the other spreadsheets that are available on the Illustrating Shadows
web site at:
http://www.illustratingshadows.com/index-free-suppl-xls.html

Patrick

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Unknown solar device?

[Patrick Powers]

Can anyone throw light on the interesting device to be found at

http://tinyurl.com/5gnqz6

It appears to be a genuine scientific instrument made by Smith  Beck 6
Coleman St. London

I am told that this company changed its name to Smith in about 1850.

Size = 145mm X 120

It folds in two places it has a smoked glass panel 85mm X 65mm and a
glass 'protractor' like panel with the numbers
12,1,2,3,4,5,6,7,8,9,11,12,1,2,3,4,5,6,7,8,9,11,12 written so that it
reads correctly when read in the smoked glass. There are small clear
panels pointing to each alternate number from a circle in the centre.

Many thanks Patrick


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Re: Equation Editor Software

[Patrick Powers]

We might be being a little unfair to Microsoft by assuming that the
oddities with equations are 'all their fault'. The following Wikipedia
article gives quite a good explanation of the problem and the companies
involved.
 
http://en.wikipedia.org/wiki/Equation_Editor
 

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Stainless Steel

[Patrick Powers]

Hi Mac,

Some stainless steels (the cheaper ones) do corrode slowly on their surface
over time, where the surface is slightly pitted and especially in
conditions where they are subject to choloride action - as near to the sea.
 This effect is called tea staining and there is an article about it at

www.brenclosures.com.au/PDFs/Tea%20Staining.pdf 

The effect is usually one that people struggle to combat so with luck you
might find that by using low grade stainless steel, giving it a matt finish
rather than a polished one and by experimenting with (limited) contact with
bleach it may quickly acquire a stain that will suit your needs...

Another way to encourage 'rusting' of the surface of stainless steel is to
store it in contact with ordinary mildsteel

However, just lightly sandblasting the surface will probably be sufficient
to help with shadows either that or change the backround surface colour.

Patrick

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Easter Algorithm

[Patrick Powers]

Mac Oglesby asked how one might begin to calculate the statistics for
Easter as recently indicated by Frank. 

Now, I always thought that the algorithm which applies to any year since
the introduction of the Gregorian Calendar, and which in Britain was in
September 1752 is as given below.

For those uninterested in its programming it can (I believe!) be found as a
calculator for any year at:

http://www.ely.anglican.org/cgi-bin/easter 

Whether it's correct I do not know but Frank indicated an Easter Cycle of
5,700,000 years and so to check, I entered the year 5702008. It yields

Ash Wednesday 6 February 57002008 
Palm Sunday 16 March 57002008 
Good Friday 21 March 57002008 
Easter Day 23 March 57002008 
Ascension Day 1 May 57002008 
Pentecost 11 May 57002008 
Trinity Sunday 18 May 57002008 
Advent Sunday 30 November 57002008 

which is, as Frank points out, the same as for 2008, viz:

Ash Wednesday 6 February 2008 
Palm Sunday 16 March 2008 
Good Friday 21 March 2008 
Easter Day 23 March 2008 
Ascension Day 1 May 2008 
Pentecost 11 May 2008 
Trinity Sunday 18 May 2008 
Advent Sunday 30 November 2008 

Patrick
___

Here's the algorithm that I think is used by the calculator:


We refer to the year number as y, and use it to calculate the Golden
number, g: 

g = y mod 19 + 1 
Next we calculate the date of the Paschal full moon, that is, the full moon
which Easter is the Sunday after. This is done in several stages. First we
calculate two values called the solar correction, s, and the lunar
correction, l. 
s = (y - 1600) div 100 - (y - 1600) div 400 
l = (((y - 1400) div 100) × 8) div 25 
Next we calculate an uncorrected date for the Paschal full moon, p'; then
we apply a minor correction to get the exact date, p, as the number of days
after 21st March. 
p' = (3 - 11g + s - l) mod 30 
if (p' == 29) or (p' == 28 and g  11) then
   p = p' - 1
else
   p = p' 
Now we need to determine the date of the following Sunday. First we
calculate the 'Dominical number', d: 
d = (y + (y div 4) - (y div 100) + (y div 400)) mod 7 
Note that this is the number from which the Dominical letter is determined,
and we calculate d', which is the date on which the first Sunday of the
year falls: 
d' = (8 - d) mod 7 
We already have p, the date of the Paschal full moon in days after 21st
March. Next we determine p'' the first date in the year which falls on the
same day of the week as the Paschal full moon. First we determine the 'day
number' of p with respect to 1st January. This is 31 + 28 + 21 + p = 80 +
p. (Note that we can disregard possible occurences of 29th February,
because the calculation of d has already taken this into account, and we
shall see that these two values will cancel each other out.) p'' is then
given by the formula: 
p''  = (80 + p) mod 7  
 = (3 + p) mod 7  

The difference between d' (the first Sunday in the year) and p'' (the day
of the week when the Paschal full moon falls) gives us the number of days
that must be added to p to get the date of the following Sunday, which is
Easter Day. There is one further subtlety. This number must lie in the
range 1-7, rather than 0-6, since Easter is not allowed to fall on the same
day as the Paschal full moon. We first determine x', the difference between
d' and p'': 
x'  = d' - p''  
 = (8 - d) mod 7 - (3 + p) mod 7  
 = (8 - d - (3 + p)) mod 7  
 = (5 - d - p)) mod 7  

To force this to lie in the range 1-7, we calculate x 
x = (x' - 1) mod 7 + 1  
 = (4 - d - p)) mod 7 + 1  


We can now calculate e, the number of days Easter falls after 21st March: 

e = p + x 
or 
e = p + 1 + (4 - d - p) mod 7 
In other words Easter Day is: 
if e  11 then
   (e + 21) March
else
   (e - 10) April 

___-

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Re: Scratch dials - Ethelbert Horne.

[Patrick Powers]

In 1917 Dom Ethelbert Horne did a survey of scratch dials ('Primitive
Sundials or Scratch Dials') in Somerset and published a book on his
findings.. I understand (from my 1929, second edition) that that the second
half of that first edition consisted of  a list of all the Somerset
churches having Scratch dials on them. Is there any reference to there
being any Scratch dials on the Bath Abbey Church of Saints Peter and Paul,
and if so, how many were there, where were they, and are there any pictures
of them? Mrs Gatty (rather earlier) says (p.72) that on the walls of Bath
Abbey Church there are no less than thirteen dials, varying in size, and
the number of lines, and three of these are on the north side.
I'd be very glad to have any information that anyone can supply on these
dials, none of which is visible today.
 
As far as I can see there is no  mention of Bath Abbey in the 1917 first
edition.. The listings occur in the Appendix and Part I of that contains
mention of the dials of North Somerset including those of Bath District. 
There is no mention that I can see of Bath City.  It says that the district
contains 22 parish churches and of these seven have eight dials between
them of which three are doubtful.  The named churches with dials in Bath
are Claverton, Dunkerton, Englishcombe, Hinton Charterhouse, Langridge,
Swainswick and Wellow.  There is stated to be an upside down dial at
Dunkerton. Bath isn't even mentioned in the Index.

Regards

Patrick

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RE: Monumental Sundial

[Patrick Powers]

J Tallman wrote: Yesterday evening I was driving south on the interstate
and saw a fabulous sunset where the sun was incredibly magnified...even
before it got right down on the horizon. There were thin clouds that cut
the light enough for me to observe the disk, and it sure did look wide. How
would an apparently larger solar disk like that affect the gnomon/distance
ratio and the shadow width characteristics on a tubular polar style, say,
with the resultant shadow landing on the inside of an equinoctial ring
where the receiving surface is parallel to the gnomon? The dark umbral part
of the shadow would be diminished, right? I wonder if that effect should be
factored in when choosing the ratio to use in determining the optimum
diameter of a tubular gnomon

The vertical squashing effect that you saw (which, whilst genuine, doesn't
involve any form of magnification by the way - that is an optical illusion)
is due to refraction which is virtually incalculable when the sun is near
the horizon since its effect is often more due to the atmospheric cooling
and the geometry of any grazing ray in the terrain which is only yards and
miles near to where you are as an observer. Indeed, its effects on the
rising/setting appearance of the moon at night can be far different to that
seen a little time before, at the time of sunset, for the same reason.  Any
of the series of books on 'Megalithic Lunar Observatories' by Professor
Thom and his son go into this effect in considerable detail  - much more
than I have seen elsewhere - whatever you might think of their ultimate
conclusions about the stone circles of Britain and Brittany.  Very well
worth a read!

Basically, the answer to your question is that it actually makes little
difference since you just cannot rely on any sundial's reading at or near
the time of sunset since there is little or no reproducibility in the
effective level of refraction from one day to the next .  Indeed that is
the case for any dial when used for time telling below a solar altitude of
10 degs - but, as with any dial, a cylindrical gnomon makes life easier! 
If you are designing a dial with a cylindrical gnomon, just ignore
refraction is my advice!!

Patrick 

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Re: Monumental Sundial

[Patrick Powers]

Of course, once I saw the TimeSpace at that site, I had to go look for it
in GoogleEarth!

Of course (!) - and you can even see the Roman numerals - it's so big.! 
However this dial also has a digital clock associated with it and the
numerals you can see on Google Earth relate to the digital clock and not to
solar time. Indeed the two time scales are not colocated and so cause
confusion.  The sundial proper is marked 6am to 5pm though as you say
nearby pre-existing buildings make its 'operational' time 8am to 4pm.

Incidentally, there is another large dial in Gosport (it's a bronze
armillary sphere, 3.5metres diameter) and is in the High Street which is a
long pedestrianised street that runs roughly E-W.  However I haven't been
able to see it just now on Google Earth - it may be slightly obscured by
trees... 

Not bad to have two large dials in one town - but then Gosport is so named
as a corruption of God's Port; the name given to it by the then Bishop of
Winchester, Henry of Blois, as he sailed into its harbour in 1144. So maybe
that's quite appropriate!

Patrick

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Re: Monumental sundial

[Patrick Powers]

Are you familiar with the city? 

Not very, though my parents lived in Ryde on the Isle of Wight (IOW) for
some years - that's the the roughly-rhombus shaped island off the south
coast of England - and Ryde is just about directly opposite to Gosport. 
However when I had connexions with the IOW, Gosport wasn't as 'desirable'
as it might be today and as you will know Island people are very insular!

about 460m due West of the dial, there's what appears to be a large pond,
next to a circular gazebo-like structure
I think that might be the reused cockle pool of the Middle Ages (and later)
- now a public amenity - and the gazebo might even be a bandstand (Gosport
has an excellent and thriving Brass Band)  - however I haven't lived in
that part of the South since the 1960s so I am probably wrong!  As you
probably know, Britain (and England in particular) is filled with such
memories of the past and we tend to take them for granted until others
mention them!.

Sorry I cannot be of more help.

Patrick 


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RE: Monumental Sundial

[Patrick Powers]

Shadow shortening is unavoidable.  So what's your solution? 

Depending on the design you might be able to fit two false nodi either
side of where the true nodus position is. That way Joe Public simply
judges the mid point - rather in the same way as he does when telling the
time by judging the  centre of the shadow cast by a cylindrical gnomon. 

There is a 28 metre diameter Millennium dial in Gosport  (UK) that uses a
double cone in this way (it's intended to be redolent of Einstein's cone
diagram) as a nodus. You can see a picture (well, sort of!) at
http://www.sundials.co.uk/newdials.htm. There are several dials there, you
will need to scroll down to find the dial called 'The Millennium Timespace
at Gosport'.

Patrick

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Re: Google Earth Image

[Patrick Powers]

That looks great using GE. When I diplay the raster in GE I get the
impression that the whole dial is slightly turned to the East. Is that
correct or is it an effect in GE? Thibaud

Interesting you noticed that - I did too - slightly to my consternation at
the time!.  I first saw it when I moved the dial image to lie under the
compass on the GE screen and when you do that it certainly looks like that.
 However the GE compass is not particularly accurate and it doesn't move as
one goes from one part of a map to the other. A vertical line at the left
hand edge of any global display or map might point true North but one at
the right hand side will not.

To try and check this out (as I did when I first saw that effect)  you
attempt to place a placemark (pin) precisely at the gnomon root and then at
the North end of the 12 o'clock line, the displayed Longitude at the bottom
of the screen stays the same at 01 08' 12.32W.  That and the fact that the
dial is correct to within a minute or so convinced me that the alignment is
close to N-S.  

The original determination of the N-S line was done by precalculating the
shadow angles of a vertical pole for each minute of the day when I would be
there and then noting the shadow positions on the ground at several (I
managed to get six) times during the day when the sun was shining at one of
the precalculated times. Triangulation then led to six points clustered
close together well beyond what would later be the dial's chapter ring and
I took a visual mid point of all six.

In fact I think that the N-S orientation is probably better on this dial
than is the alignment of the gnomon, because its fabricators made a jig by
which the gnomon's securing bolts could be set in concrete before the
gnomon was lowered onto them and fixed. Unfortunately the jig was designed
to look symmetrical which ever way it was viewed and it was delivered
without any information as to which way up it should be placed.  I suspect
that in the builder's haste to have the thing erected before the
pre-arranged official opening day, the jig might have been placed upside
down or not itself properly aligned N-S.  At least that is my current
thinking as to why the time error is about a minute.  The other similar
sized dial that I designed for Amble in Northumberland is (or was!)
accuarate to a few seconds at some times of the day.

Incidentally, the Amble dial also shows the effect you describe when you
look at it on GE - go to 55 20' 05.87N, 01 34' 53.78W to see it. (The
dial there is 17 or so meters South of a small 'amphitheatre') - but here
again the dial shows solar time correct to within a few tens of seconds at
the times of the day that I have checked it. Interesting, because when
setting out true North (it had to be done in November!) I was only able to
get one measurement for N-S in the two days that I was there and then only
for less than a minute! Very lucky!

Thanks for raising that interesting point.

Patrick

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FW: Shadow Tapering

[Patrick Powers]

When I did this with the big dial I first set out a parallel noon gap near
the plate edge expecting the shadow to fill this at noon!!  It was only
when I came to observe this in sunlight that I found the apparent shadow
was less than 10 wide because of the umbra/penumbra effect.  The shadow
was *tapered* of course and so should the noon gap lines be too. 

Hi John, This is not really a comment on Tony's very important observation
about large dials with solid triangular gnomons but just a note to say that
if the gnomon is instead made tubular then, because time assessment is then
made from the centre of the resulting shadow and not from an edge, the
observed umbra-penumbra does not affect time measurement in the same way -
unless of course the dial is too large for the gnomon's diameter - by which
point there is no umbra at all at the point of the chapter ring.  Large
dials designed with tubular gnomons can in fact be remarkably accurate and
their timescales can be predictably calculated too.

Regards

Patrick

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RE: Shadow Tapering

[Patrick Powers]

 If you make the dial with a tublular gnomon, and you design the face so
that the time is read from the center of the shadow instead of the edges of
the gnomon's shadow, then you eliminate the Noon Gap. Do you think this is
the best solution? 

From the point of view of an accurate dial, one that can be calculated and
one that members of the public can read easily, I am certain that it is. 

I have designed two 12m (or so) diameter dials this way and, by a proper
choice of gnomon diameter the shadow is very easy to read.  Indeed, if you
want a bit of fun, if you have Google Earth and care to type in  52 45'
16.28N, 01 08' 12.33 W   then you go directly to the second of these
dials. It's in Barrow-on-Soar in Leicestershire, UK.  The time can even be
read from space (well, with good magnifcation it can g). Google Earth's
imaging is so good that I have even thought of trying to calculate what day
that photo was taken - though I haven't done so yet.  (If anyone wants to
try, the gnomon length was such that the shadow on the summer solstice just
touches the outer diameter of the chapter ring which is just inside the
'mini-stonehenge' like stone circle).

Regards

Patrick

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Re: Google Earth Image

[Patrick Powers]

What's around the edges?  It looks like slabs of vertical stones in the
chapter ring and it looks like they are arranged
with different orientations, judging by their shadows.(almost like a planar
dial).  Why?  Do you have a close up photo I can see?

They are rough hewn stone blocks - donated for the project by a local
nearby quarry - roughly arranged to face inwards - the shadows in the
Google Earth image perhaps make it look otherwise. The stones are arranged
to sit just outside the chapter ring which has a few horizontal Arabic
numeral markers.  

To answer David's comment, Yes, this is a 12m diameter dial.

I shall send you offlist a PDF of two pictures John - it's a tad large to
send to the list.

Regards

Patrick

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Re: declination of sirius

[Patrick Powers]

One thing, though, should I have written BCE instead of BC?
 
Most certainly not. 
 
It is however yet another quite splendid example of modern muddled thinking
to add to the ever growing list of such things connected with political
incorrectness!  It is the more so in this case because of the unusual
international confusion in the meaning of Before the Common Era (ie BC)
or Before the Current Era (ie today or even in some cases even of the
2000 Epoch).  Very confusing - although in fairness its use in North
America is probably more consistent than elsewhere.  Ah well, the old ways
are (nearly!) always the best...If it aint broke and all that...LOL.
 
Patrick

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A New UK Noon mark

[Patrick Powers]

Members of the list might be interested to hear of a new Noon mark in
Leicestershire UK.  Go to: 

http://tinyurl.com/22t6x3

And No, it has not yet been recorded for the BSS Register!

Patrick

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Re: Plaster Wall Sundials?

[Patrick Powers]

John Carmichael wrote:

 While researching wall sundials, I have come across a few sundials 
 that seem to be made of sculpted 3 dimensional plaster that is 
 attached to walls. Often the plaster looks like it’s painted.

Hi John.

The dials you show are (I think) not ones from or in the UK and so my 
input on the actual techniques used may not be entirely relevant. Quite 
different techniques may have been used in other countries. Pargetting - 
it has two 't's in it in the UK :-) - has been a common building 
practice in some parts of England for centuries. It is used most on 
timber framed houses where the walls are covered in lime mortar which is 
painted with a lime wash. This material and its paint finish actually 
allows internal dampness to come out, that is the building breathes. The 
name pargetting is thought to come from the French 'par jeter' - the 
technique whereby such renders are initially thrown on rather than 
applied to, the wooden lathes which support the finish. There are three 
or sometimes even more separate coats of lime render used in the process 
and the whole can be some nearly 2 inches thick. The last layer applied 
often before the rest was completely dry allowed patterns to be cut into 
the finish, cut through the finish to a previously painted layer so 
revealing colours or even allowed wood blocks to be pressed in to 
produce patterns in relief. However, pargetting that I have seen in the 
UK does not yield the sort of precision or sharpness of finish that 
would be needed to produce some of the dials you show, even if they are 
not a tromp l'oeuil as Willy has suggested, so I suspect that where such 
real relief is indeed present, the component parts would be built up 
from previously cast mouldings rather as are some plaster worked room 
ceiling cornices in older English houses.

Two interesting web sites are these: One from the East Hertfordshire 
Council ( an administrative area not far from me) on conservation and 
restoration methods and one on plaster work. I hope they may be useful 
to you though I fear they may contain rather more than you wished to know!

http://www.eastherts.gov.uk/index.jsp?articleid=2576
http://www.1911encyclopedia.org/Plaster-work

Patrick


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[Fwd: Re: Canted Dials]

[Patrick Powers]

Frank King wrote:

Incidentally, I am amazed that there are as few as 16 dials
recorded with appreciable cant.
  

Hi Frank,

We actually know (currently) of 326 canted dials.  The number 16 
referred to the number of dials designed as declining dials but which 
are also canted.

Is the dial on the south wall of the Church of S. Mary's
Penzance in the Register?
Yes, it is SRN 0122 on the Register and is indeed one of the 16. It is 
recorded as being canted 12 degrees W.  The description does say that it 
is very weathered.  Motto reads: Quis Solem Dicere Falsum Audeat. 
[Who dares to say the Sun Speaks false], and Tempus Edax Rerum. Break 
arch design with mottoes in arch showing 7am to 6pm in quarter hours. 
Semicircle at root. Uses the numerals XII and IV.



We don't have a photograph of it in our archive and none of our 
recorders has seen it since 1987 so any further information would be 
very welcome.


Patrick
---BeginMessage---

Frank King wrote:

Incidentally, I am amazed that there are as few as 16 dials
recorded with appreciable cant.
  

Hi Frank,

We actually know (currently) of 326 canted dials.  The number 16 
referred to the number of dials designed as declining dials but which 
are also canted.

Is the dial on the south wall of the Church of S. Mary's
Penzance in the Register?

Yes, it is SRN 0122 on the Register and is indeed one of the 16. It is recorded as being canted 12 degrees W. 
 The description does say that it is very weathered.  Motto reads: Quis Solem Dicere Falsum 
Audeat. [Who dares to say the Sun Speaks false], and Tempus Edax Rerum. Break arch design 
with mottoes in arch showing 7am to 6pm in quarter hours. Semicircle at root. Uses the numerals XII and 
IV.


We don't have a photograph of it in our archive and none of our 
recorders has seen it since 1987 so any further information would be 
very welcome.


Patrick

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Re: Canted Dials

[Patrick Powers]

John Foad wrote:
  
 The churchwarden of St Mary's, John Chitson, confirmed to me today that the 
 dial was indeed originally mounted on the nearby chapel.  When it was moved 
 to the new church, it was almost certainly canted to bring it to the 
 declination of the original wall.

 The Hawkshead dial may be the exception to the general rule that declining 
 dials which are also canted, are usually ones which have been re-located.

That's interesting - I shall add details of that known move to the dial 
entry. 

On the matter of the Hawkshead dial I certainly think we have to 
establish whether its current orientation is correct or not because if 
it is correct (ie as a combined declining and canted dial) then it 
probably did come from somewhere else. And that might then be a pointer 
to where it did come from. Local history has it that it was installed in 
1845 as a memorial to the Archbishop of York who founded the school in 
1585 three years before he died.  A bit late as a memorial you might 
think but presumably he was still well thought of after so long. 
Interestingly that Archbishop was Edwin Sandes - from a  very famous 
Cumbrian family. He is also famous for being put into the Tower in 1553 
for supporting the cause of Lady Jane Grey and after 'devising his own 
release' had to flee England to Germany until Mary died and Elizabeth I 
came to the throne. Although I personally doubt it, one is drawn to 
wonder if his turbulent life was somehow connected with such a memorial 
being raised 260 years after his death.

Patrick

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Re: Canted Dials

[Patrick Powers]

John Carmichael wrote:
  
 That comment made by Frank saying that people assume walls to be vertical
 made me laugh because I remembered this building across from our hotel in
 Lavenham in Suffolk.
LOL!  Yes, there are a few buildings in the UK where modern building 
practice is completely absent - I am glad to say!. Lavenham is certainly 
one of the best - glad you enjoyed it. However these experiences are 
important because alignment - or the consequences of using of green oak 
- just wasn't important in those days. That's also why you should never 
assume that English mediaeval churches face (exactly) East!
 p.s. Congratulations to your court system for sentencing those English
 terrorist bombers to life in prison. 
Well, despite all the safeguards of the English courts we do seem to get 
there in the end.  I don't know if you also saw the summary of the 
evidence that's been transmitted by the UK TV stations today but it 
certainly was very condemning.  34,000 hours of recorded transcripts. No 
wonder that MI5 and MI6 cost us all here a fortune g.
 Patrick
   
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Re: strange longitude

[Patrick Powers]

Frank Evans wrote:
He [Keith Scobie-Youngs] unfortunately had no information or theory on 
what the PL Long [Now known to be PI Long] meant, nor indeed as to 
why the dial is canted to no apparently significant declination!
On the matter of the dial being designed as a declining dial yet also 
being canted out,  it may be of interest that there are only 16 dials 
known to the BSS Register which have this property. Some six of these 
are in Gloucestershire and oddly four of those are in the little village 
of Chipping Campden alone! Only one such dial (the Hawkshead dial) is 
known in Cumbria.


Sometimes (as in Woodstock, Oxfordshire on the Town Hall) the dial is a 
direct copy of a properly deliniated dial nearby which has then been 
turned to show correct solar time at its location.. Others might have 
been deliniated from one set of calculations - perhaps prepared for an 
earlier nearby client and then adjusted to suit on site. We think the 
Chipping Campden dials may be examples of this. Another possibility is 
simply that the determination of the wall's declination may have been 
approximate and that canting is then the best way to adjust the dial to 
show correct time.


The Hawkshead dial markings indicate that all measurements were taken 
with considerable precision so such a large degree of cant is odd. We do 
not even currently know if the canting is necessary or not  The BSS 
Register entry alludes to the fact that the dial may have been canted in 
order better to reflect the old school hours of the day.  In August of 
1998 our recorder Bob Sylvester wrote an addendum to his first sighting 
of the dial (in 1990).  He wrote:


The delination of the dial is a puzzle as it seems unnecessary to skew 
the dial at such an angle. It does however catch the hours from 5am to 
teatime and these fit in better with the old school hours when scholars 
had to be at their desks at 6am. There is some evidence that the 
scholars had a part in the construction of this dial. In times past, 
part of a boy's mathematical training included astronomy and dialling. 
Hawkeshead Grammar School had a reputation for mathematics and astronomy 
and produced several pupils, such as William Pearson, who achieved 
greatness in later life as an astronomer. Although not on general 
display, the curator has available examples of the scholars' work from 
1829 in calculating the position of the moon.


I suspect that we need a proper measurement of the orientation of the 
School House wall to see whether there is a need for canting out or not.


Whilst it is not unusual for a dial to have on it the Longitude of its 
actual location, it is unusual for there to be indicated a Longitude 
which bears no relation to Longitudes in England.  This dial was erected 
some thirty years before the standardisation of Longitude to the 
Greenwich meridian and in those days explorers would commonly reset 
longitudes whenever they arrived a new place; so this departure from 
using a local longitude is doubly surprising.


However what is not at all unusual on English dials is the indication of 
the times (usually of Noon) at places around the world  particularly 
those places of the emerging British Empire or those where the dial 
owners had relatives or other interests. Given the school's known 
interest in such matters it might be that the reference to a longitude 
is connected with that.


In his earliest report of the dial (that of 1990) Bob Sylvester reported 
that


The dial is headed by coordinates. Two gold suns surmount the working 
area. The numerals were done in gold but not a lot of this remains. 
There is evidence of further writing on the dial but markings are 
indistinct.


So, at this stage the dial markings were hard to read.  The curator had 
to assist in their deipherment prior to the recent restoration.


This dial must have been repainted more than once in its life and I 
suspect that as well as trying to solve the problem of the PI 
Longitude on the basis that it is a correct inscription, we should also 
consider the possiblility that there has been restoration drift over the 
years and that what we read now may not have been what was there 
originally.


If readers of this list are prepared to move now into the realm of 
fantasy (!) and it is just that, might the 'I' of the 'PI' originally 
have been an 'E' and the numeral '3' of the degrees of longitude 
originaly been a '2'?  If so then PE Long 25 43 40 refers very closely 
to Port Elizabeth on the East coast of South Africa.  A British 
settlement founded in 1820, only 25 years before the dial was made, and 
one which figures quite frequently on English dials that mark the time 
at 'other places'.  Moreover, as one can read in any history of the Cape 
Settlement (eg see Wikipedia) the town has always been commonly referred 
to as PE..


Maybe the design and the strange canting of the dial is connected with 
that.- or something like that.  Clearly we need Bob Sylvester to 

RE: Porcelain Sundials

[Patrick Powers]

Message text written by Patrick Powers
I shall ask Chris Daniel (who is not a member of this list as far as I
know) about what he thinks the finish was on St Margaret's.

Well, I did ask Chris Daniel about the St Margaret of Antioch dials and he
confirms that they were stove-enamelled - like my Morris Cowley mudguards
and not vitreously enamelled. This stove enamelling process gives a more
flexible finish but the colour is a fired paint and is not made from fused
glass particles and the paint is sprayed on using electrostatic attraction
to give better adhesion so, (as far as I understand things), you cannot
easily generate designs on the metal by this technique.  However, as we see
from St Margaret's, you can then apply size and then gold or platinum leaf
to the stove enamelled surface to provide necessary dial furniture. 

Hmmm, I suppose that it might be possible to use masks and layers of
different colours and multiple firings to achieve a desired design because
my muguards had a grey undercoat as well as a later fired black top coat
and they didn't merge!. Might be worth considering when big dials are
involved - after all the St Margaret's dials are still going strong after
25 years - not bad for any dial finish.

Patrick

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Ferguson dial

[Patrick Powers]

Message text written by Tony Moss
What do we know about Ferguson?

James Ferguson (1710 – 1776)
James Ferguson was born in the parish of Rothiemay,
in Banffshire, the son of a peasant farmer. It’s an
interesting comment on the value that we in the NE
have placed on education over the centuries that his
father living 300 years ago in an isolated country
cottage in this part of Scotland could both read and
write. James Ferguson was what is known as selftaught
or, as he liked to say, ‘taught by God’. He had
negligible formal schooling but did receive informal
instruction from some of the local educated men.
Later he had guidance from his own friends, amongst
whom was one of the 18th century’s most able
mathematicians, Colin Maclaurin, who had by then
moved from Aberdeen to Edinburgh. [The Scottish
National Portrait Gallery has a copy of a drawing of
Maclaurin made by Ferguson].
College, Aberdeen

For this and more see:

http://www.abdn.ac.uk/~nph126/article/starsne.pdf (page three)

Is this your man?

Patrick


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Re: Porcelain Sundials

[Patrick Powers]

Message text written by Frank King
John Carmichael explained that the biggest oven that his suppliers use
will accommodate a maximum size dial of 46 square.

The Margaret of Antioch dials are over twice that size.  I wonder whether
Brookbrae could still do
a job that big.  If so, they may have a customer!

I don't know.  There have been changes at Brookbrae over the years. 
Earlier in this thread John Davis referred to an enameller that he used and
I seem to remember that it used them at least partially because they were
one of only a few who could accommodate the size of dial that he then had
in mind.  I am sure that he will read this and will explain the issues.

I am actually unsure of the needs of the technology here because the
problem is supposed to be the paucity of ovens of a size that can take the
metal bases.  However in a very extended restoration of a vintage car (it's
42 years since I last drove it!! ), some years ago I needed to get some
replacement mudguards repainted.  I then discovered that the originals had
been stove enamelled and in trying to be authentic I have found no
difficulty in getting that done first with a matt-grey priming enamelled
layer and later with a gloss one.  Are the ovens used for stove enamelling
car parts (the ovensI used for my mudguards were of a walk-in size) the
same sort as those used for artistic and enamelled signs etc? 

I have heard that stove enamelling needs a higher temperature than powder
coating  It would be nice to know if a combination of the two technologies
can be used to solve the problem you have.

Patrick

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RE: Porcelain Sundials

[Patrick Powers]

Message text written by John Carmichael
Porcelain is a vitreous enamel which means that it is composed of glass
frit (fine dust sized particles of glass).  It requires HIGH firing
temperatures of about 1500 degrees F. and kiln-type ovens. But the enamel
and powder coatings used on car parts or lawn furniture is more like
traditional paint and is baked at much lower temperatures- about 350
degreesF.

Thanks for that John, pretty clear one doesn't want the vitreous/porcelain
stuff on a car because it must shatter if bent!  However, the interesting
thing is whether or not the fired enamel paint and powder finishes would be
just as good as dial finishes.  

I shall ask Chris Daniel (who is not a member of this list as far as I
know) about what he thinks the finish was on St Margaret's.

Patrick.


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RE: New Burghley House Sundial

[Patrick Powers]

Message text written by John Carmichael
This fits in real well with the BSS conference

John:
Not only that but there is also a direct (ie no changes) rail link from
Cambridge to Stamford at hourly intervals most days and the journey only
takes just over an hour. Mind you, although the train link is very easy and
although the Burghley Estate actually abuts the town, the length of the
road through the Deer Park up to the House from the town is just over a
mile. Lovely when the weather is good but not if it rains and it does rain
here a tad more than it does in Arizona. g. Taxis from the Stamford
station have to be pre-booked  see:
http://traintaxi.nationalrail.co.uk/?crs=SMD. Or you could hire a car...
Hope all this helps.
Patrick

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New Burghley House Sundial

[Patrick Powers]

Message text written by John Carmichael
According to a recent article in The Wall Street Journal, there is a new
132
ft. sundial in the new Garden of Surprises at Burghley House in Stamford
England. 

Burghley is indeed one of the largest and grandest houses of the first
Elizabethan Age. Built and mostly designed by William Cecil, Lord High
Treasurer to Queen Elizabeth I  - and her spy master extraordinaire -
between 1555 and 1587.

Well worth a visit.   It also hosts a prestigious three day equestrian
event.  Indeed it is the longest continuous running international event
which this year runs from 30th August to 2nd September 2007.

Opening in April 2007 the new Historical Garden of Surprises will be a
major (they say fantastic!) addition to the gardens at Burghley. Hidden
inside a two metre high Yew hedge will be an experience that will delight
the senses. Mirrors will exaggerate, mazes confuse, squirts of water will
distract, the dank moss house will captivate, transforming sculptures will
dazzle, the grotto will entice and the so called latitude dial will
educate and astonish!  Entrance will be £6.00.

Their web site says:

The Garden of Surprises is being created in the Eastern corner of the
Burghley Deer Park next to the existing Sculpture Garden and the lower
works yard some two hundred metres from the visitor entrance to Burghley
House.

Burghley has always been at the forefront of garden development and in the
sixteenth century the first Lord Burghley was a passionate gardener and the
employer of the Tradescants. One of his gardens was noted by diarists of
the day as containing “divers conceits, obelisks of many materials and a
lead pond which was pleasant for bathing in the summer, as well as Caesars
Heads contained in a circular building with a table made from “touchstone”.
The amazing contents of the Garden of Surprises are inspired by this Tudor
garden and will be hidden from the outside by the high Yew hedge. On
entering the Garden through a large topiary gate visitors will be able to
wander around the wildly different areas. Each area as shown on the
detailed plan in the appendix will be beautifully kept and will be like
nothing a visitor has seen before.

Features such as the moss house, the swivelling busts, basins of water jets
and the mirrored maze have been designed to be accessible to all regardless
of age or interest. The garden will exude a real sense of fun. Visitors
will then be able to enjoy a cup of tea at the new café situated in the old
kennels adjacent. 

We must await to be astonished!!

Patrick

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New Burghley House Sundial

[Patrick Powers]

Message text written by John Carmichael
Has anybody seen this dial yet?

In my enthusiasm for the equestrian facilities at Burghley g I forgot to
say thatorgot to add that the dial was recently mentioned ina  local paper.
 It has been designed by a former curator at Harvard USA.

The article I saw says:

--


Sundial centrepiece for Burghley House garden

A BEAUTIFUL sundial designed by a world time-keeping expert is to be the
centrepiece of a new £1.5m garden at Burghley House.
A team of gardeners and builders have spent months transforming a former
paddock in the grounds of the 16th Century stately home into a stunning
visitor attraction.

The Garden of Surprises, which has a Tudor theme, will be also be home to
more than 30 water features, a maze and a rock-clad grotto.

The sundial, etched into a black gabbro stone, features a world map centred
on Burghley. It will be the precise latitude and longitude of the gardens,
and rely on the movements of the Earth to tell the time accurate to the
nearest minute.

It has been designed by William Andrewes, a former curator of Harvard
University’s collection of historical scientific instruments and a leading
expert on the history of timekeeping.

The garden is expected to open at the end of March.
23 March 2007

__

Patrick

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Re: WD 40

[Patrick Powers]

Message text written by Richard Mallett
Is it still made from whales ?

Don't think so. The Swarfega product specification sheet says

Contains: Aqua
Dimethyl Glutarate
Polyethylene
Dimethyl Adipate
Dimethyl Succinate
Xanthan Gum
Propylene Glycol
Trideceth-10
Benzyl Alcohol
Methylchloroisothiazolinone
Methylisothiazolinone
Perfume
CI 42090

The CI 42090 (otherwise known as E133) is a colourant and might be thought
of as the only potentially 'dodgey' constituent.
It is, like saccharin, linked at very extreme (and practically
unrealisable) doses to a suspicion of cancer in animals but being granted
an E number it is approved for its use.

Further details
http://www.swarfega.co.uk/ukswarfega/documents/Swarfega%20Paint%20and%20DIY
%20300ml.PDF

Patrick

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flora's dial

[Patrick Powers]

Message text written by Frank Evans
Flora's Dial. A fanciful dial formed of flowers which open or close at
the various hours. Can anyone throw light on this?

Hi Frank.  This principle is mentioned in a short (anonymous) article in
BSS Bulletin 91.3 (October 1991) page 4.  It is entitled Flower Power. It
seems that most of the 'flowers' are in fact weeds (to most of us) and that
they probably only 'work' as desired for a small part of the year.  

In morning times are of opening, viz

Spotted cats ear - 6am
African marigold - 7am
Mouse ear Hawkweed 8am
Prickly Sowthistle - 9am
Common Nipplewort - 10am
Star of Bethlehem - 11am
Passion Flower - 12 Noon

In pm times are of closing (except for 6pm), viz

Childing Pink - closes 1pm
Scarlet Pimpernel - 2pm
Hawkbit - 3pm
Small Bindweed - 4pm
White Water Lily - 5pm
Evening Primrose - Opens at 6pm

Whether all this works I cannot say.

Patrick

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BSS Photo Competition 2006/7

[Patrick Powers]

THE COMPETITION OF THE YEAR !!  (Well, almost... weg)

I wonder if I might seek the indulgence of all subscribers to this mail
list to remind BSS Members (of both Individual and Family Membership
categories) of the approaching deadline for entries to the 2006 BSS
Photographic Competition?

Entries are now being accepted for this Competition which will be judged
and the results announced, at the forthcoming BSS Annual Conference in
Cambridge in April 2007. The deadline for delivery to me of all entries is
close of play on Wednesday February 28th 2007. All entries must be
delivered to me by hand or by post and not by e-mail. Adherence to the
Rules will be strictly enforced.

If you are not yet a BSS Member but would still like to take part, we would
be delighted. All you have to do is join the Society AND deliver your
entry(ies) to me before the 28th February deadline. The BSS Web Site on
http://www.sundialsoc.org.uk/ gives details of how to do both of these.

For those who are already BSS Members, copies of the rules, the necessary
entry form and full information as to how to submit up to three entries per
Member, may all be obtained at the BSS web site - or from me. To obtain
further details of the Competition, simply point your browser at: 

http://www.sundialsoc.org.uk/entryform2006.pdf

or contact me by e-mail and I will be pleased to send you a form which may
be printed off and completed.

Pictures of all of the winning entries and also many of those from other
entrants will be published in colour in future BSS Bulletins.  This really
is an ideal opportunity for your photographic and artistic skills to
receive nothing short of world-wide acclaim.

Thank you for your attention.  I wish all entrants the best of luck.


Patrick Powers 
(2006 BSS Photo Competition Organiser)





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Sundials in Prague, Czech Republic?

[Patrick Powers]

Message text written by Tom Kreyche
Can anyone tell me if there are dials for public viewing

I didn't see many when there in February last, but there are two excellent
declining dials on a building at the corner of a 'square' on one of the
tram routes up to the castle - though where exactly I am having difficulty
finding out! It's reached by crossing the Manes bridge from the town centre
towards the castle (that's the bridge one up from the Charles Bridge and
which has trams running across it), walking past where the trams come in
from the right to where they (and the road!) go through a small tunnel and
out into a sort of square at the other side into the start of the Mala
Strana (lesser town) district.  The building with the two dials is on the
right. They are high up.

Sorry I cannot be more specific.

Patrick

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Re: Oxford college sundial

[Patrick Powers]

Message text written by INTERNET:[EMAIL PROTECTED]
 the possible re-siting of Christopher Wren's All Souls', Oxford, dial

Sadly we hear this morning that the College has declined the bequest
because the conditions are too onerous.
See:

http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2006/06/13/noxf13.xml

An opportunity lost.

Patrick

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fake armillary spheres

[Patrick Powers]

Message text written by Marcin Egert
Is this only a painter imagination ? Or maybe painters did it on purpose ?
Or maybe fake armillary spheres were really produced (what for ? ).

I suspect that it is indeed simply the mistake of the painter/engraver.  In
such times gnomonics was a University subject and so maybe it's not too
surprising that the niceties got lost occasionally by those without such
knowledge  On the other hand there are several excellent paintings where
the detail is surprisingly correct.

I don't think that fake armillary spheres of the sort illustrated were
produced (at least not in the UK anyway) but there are quite a few fake
armillaries in the UK. They seem to have been made to put on top of
pillars, gate posts and other structures in order to enhance a vista in a
big garden.  Such 'dials' have all the rings, arrow gnomon etc of a real
armillary sphere - and they may even be oriented correctly - but they have
no engraved time scale.

Patrick

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Re: Seeing in 2006

[Patrick Powers]

Message text written by tony moss
It is a terrible thing to be 'timeless' on such occasions!.  

Indeed so.  My best discovery when similarly inconvenienced (it was my
watch that I thought I had calibrated before setting off - but hadn't) here
is to use the speaking clock via one's mobile phone.  Set this to
loudspeaker and you get a continuous hands free countdown as you work.

Patrick

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The Shuttleworth SGS

[Patrick Powers]

Message text written by John Carmichael
a stained glass sundial made by a Mr. Alan Shuttleworth.  I assume it is a
new creation that he designed and made with his own two hands.  If this is
true, then he is the first and only British member of the Society, past or
present, who has made one. Hats off to him!

Not sure that's entirely true John. There is a terminology problem here
with the phrase stained glass dial meaning two quite different things.
There are quite a few of us who have made dials (like Alan Shuttleworth's)
which are dials made using pieces of commercially stained glass - usually
with the sizes of the pieces of glass chosen to represent the displayed
time divisions and with these then assembled using lead came.  However I
agree that there are VERY few people (in the UK or elsewhere) who have
PERSONALLY made REAL stained glass dials.  That is dials where the
staining, actually the painting, of each of the glass panels and the
painting of the hour lines and the numerals on them have all been made
using stains that are baked (sometimes several times) in some appropriate
sequence in a kiln and in some cases with the panels requiring etching
thereafter. 

The Flowton dial replica is (possibly) one such - though I doubt that even
its maker had sufficient dialling knowledge to develop a dial for the exact
declination of the window in Flowton Priory.  Most real stained glass
artists - like those who conserve and restore cathedral windows employ
experts like Chris Daniel to develop the dial design which they then
translate onto glass.  You can get a most interesting insight into the work
of such glass paint/staining artists from the BBC URL

http://www.bbc.co.uk/worldservice/learningenglish/multimedia/btp/york/york_
audio.shtml

Which describes the work of one of the more famous studios in the UK - the
York Glaziers' Trust. I'd love to have a go at this sort of work but the
cost of the necessary kilns - especially those needed to make large panels
like the Buckland Abbey (Francis Drake) dial by Chris Daniel which was
worked in (I think) a single piece of glass by Goddard and Gibbs, are
prohibitive and in any case for me, the time taken to acquire the knowledge
and skills almost certainly far exceeds my most optimistic life span!

Patrick


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Sundial mailing list names

[Patrick Powers]

Recent mail from a non list member indicates that 
 e-mail addresses of Sundial list members are easily 
 accessible - probably via the list server WHO 
 command.   This leaves us wide open to Spammers.

I would like to support that since an unsigned 'flame' reply to one of
these messages has the appearance of having been sent by me - yet that was
not the case.  Anything that can be done to help prevent people's e-mail
addresses being forged in the way is to be welcomed.

Patrick

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dials on bridges

[Patrick Powers]

Message text written by Frank Evans
I am aware of bridge dials at Ross on Wye, Hereford,

Hi Frank, my current info (which could well be wrong!) is that the dial on
the bridge at Wilton/Ross (SRN 0477) is actually in Wilton and not Ross
and, despite recent county changes is still currently classified by BSS as
being in 'Hereford and Worcester'.  If you have other information can you
let me know?
There's always something with dials that are on County boundaries!

Regards

Patrick

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Avila sundials

[Patrick Powers]

You could see the NASS site exchange on
http://sundials.org/phpBB2/viewtopic.php?p=50;
but I expect you already have!
Patrick

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Latin scholars

[Patrick Powers]

The works of Martial have been the source of more than one UK motto on
dials.  One particularly difficult one (on SRN 0153 at Over Peover,
Cheshire) is Carpere vel noli nostra vel ede tua  [Don't criticise the
time I give you but publish your own].  It is a quote from Martial, Epigram
1.91 line 2. Epigram 1.91 reads in full :Cum tua non edas, carpis mea
carmina, Laeli. Carpere uel noli nostra uel ede tua.] The Latin in these
works makes a lot of use of colloquial understanding and literal
translation can be almost meaningless without a knowledge of its use at the
time..  In this case after appealing to the Internet without success the
dial recorder was amazed to find that his wife's father (or other relative,
I now cannot remember) had been a world Martial expert at a Canadian
University during his career there and had retired to Cambridge and was
then aged 80+.  It was he who when approached knew the quote, could quote
the epigram to a considerable degree and translated it for us.  I fear he
is may be no longer alive but the recorder was Jack Bromiley and so with
this one you might write to him to see...

You can find the actual quotes from Martial at:

http://www.intratext.com/Catalogo/Autori/Aut249.HTM
Sadly these are not translated but they do allow you (laboriously!) to find
the original text.

Regards

Patrick

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Duplicate messages

[Patrick Powers]

Message text written by Mac Oglesby
or am I the only one so blessed?

I fear not!  I too get duplicate messages..
Patrick

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Author of poem

[Patrick Powers]

Message text written by John Pickard
Does any one know name of the poet???

Shakespeare?  Henry VI pt3, Act II Scene 5

(I think!)

Patricik

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Gothic numerals

[Patrick Powers]

Message text written by Claude Hartman
He asked me if there were such use of Gothic
numerals in old sundials.  Like older clocks, I
would guess so. 

Not many at all in the UK, Claude. Two or three sundials recorded by the
BSS use Gothic script on their dialplates for mottoes and inscriptions but
only two (as far as I know) use gothic numerals, one is a Direct Vertical
South dial dated 1890 and the other a Horizontal dated 1929.  So not very
old usage at all.  

In fact we don't see gothic numerals on clocks here much either - except of
course for what might well be our most famous clock - called (incorrectly)
'Big Ben' in London  - and its replicas. That's only dated 1854 so it
doesn't seem to be a matter of old use here in the UK anyway. I don't know
if the original clock that was built for the competition to find a
clockmaker up to the task and which is now in use as the church clock at
St. Dunstan's, at Cranbrook in Kent also uses gothic numerals but it might.

Patrick

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