Re: Advice wanted, on 'Analemmatic' sundial orientation
Dear Frans, I happily endorse all your suggested improvements. I'd add the possibility of using 3M's retro-reflective material, as on traffic signs, on the hour-markers or, if the layout is reversed on the centre-post. I just hope Mr Phillips appreciates all the hard thinking we've done on his behalf. John Lynes --- On Mon, 7/7/08, Frans W. Maes <[EMAIL PROTECTED]> wrote: > Dear John, > > Do you think Mr. Phillips really is willing to go along > with such an > idea? If so, I have been considering the options a bit > further. > > The explanation in Karl Schwarzinger's webpage has > January outermost and > December innermost. For a human shadowcaster, it would be > easier to have > June innermost, as his/her shadow will be short. Next May + > July, which > see about the same solar declination, then April + August, > etc. The > spacing of the month rings can be adapted to the average > person's shadow > length in that month. You might stop at March + September, > as there is > not much going on in the remaining months, according to the > Year > Calender in the Estate's website > (http://www.kentwell.co.uk/). > > The type of pavement/planting may limit the accuracy of > reading. If one > does not care about high precision, one could average the > azimuth values > of two months (like May and July) and use this single > value. > > The placement of the month names is free. They could be > aligned with the > main driveway, thereby fulfilling another of Mr. > Phillips' requirements. > > We still have the wish/requirement for scales having the > hour points at > the south side. This could be met by reversing the lay-out, > as follows: > Rotate the rings by 180 degrees. The person walks the ring > for the > present month until his/her shadow points at the center > spot/post. Then > he/she reads the time from his/her position. This makes the > dial even > more 'interactive' than the usual analemmatic dial! > > What do you think? > > Best regards, > Frans Maes > > [EMAIL PROTECTED] wrote: > > YES!!! Why didn't any of us think of this? > > John > > > > > > --- On Sat, 28/6/08, Frans W. Maes > <[EMAIL PROTECTED]> wrote: > > > >> From: Frans W. Maes <[EMAIL PROTECTED]> > >> Subject: Re: Advice wanted, on > 'Analemmatic' sundial orientation > >> To: [EMAIL PROTECTED] > >> Cc: sundial@uni-koeln.de > >> Date: Saturday, 28 June, 2008, 9:51 PM > >> Dear John, > >> > >> What you describe resembles an azimuth sundial. > See for > >> instance the > >> Plochingen sundial in Karl Schwarzinger's > collection: > >> http://members.aon.at/sundials/bild44_e.htm > >> In this case, there would be no clear-cut > alignment with > >> anything, > >> including the (in)famous path... > >> > >> Best regards, > >> Frans > >> www.fransmaes.nl/sundials --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Advice wanted, on 'Analemmatic' sundial orientation
Dear John, Do you think Mr. Phillips really is willing to go along with such an idea? If so, I have been considering the options a bit further. The explanation in Karl Schwarzinger's webpage has January outermost and December innermost. For a human shadowcaster, it would be easier to have June innermost, as his/her shadow will be short. Next May + July, which see about the same solar declination, then April + August, etc. The spacing of the month rings can be adapted to the average person's shadow length in that month. You might stop at March + September, as there is not much going on in the remaining months, according to the Year Calender in the Estate's website (http://www.kentwell.co.uk/). The type of pavement/planting may limit the accuracy of reading. If one does not care about high precision, one could average the azimuth values of two months (like May and July) and use this single value. The placement of the month names is free. They could be aligned with the main driveway, thereby fulfilling another of Mr. Phillips' requirements. We still have the wish/requirement for scales having the hour points at the south side. This could be met by reversing the lay-out, as follows: Rotate the rings by 180 degrees. The person walks the ring for the present month until his/her shadow points at the center spot/post. Then he/she reads the time from his/her position. This makes the dial even more 'interactive' than the usual analemmatic dial! What do you think? Best regards, Frans Maes [EMAIL PROTECTED] wrote: > YES!!! Why didn't any of us think of this? > John > > > --- On Sat, 28/6/08, Frans W. Maes <[EMAIL PROTECTED]> wrote: > >> From: Frans W. Maes <[EMAIL PROTECTED]> >> Subject: Re: Advice wanted, on 'Analemmatic' sundial orientation >> To: [EMAIL PROTECTED] >> Cc: sundial@uni-koeln.de >> Date: Saturday, 28 June, 2008, 9:51 PM >> Dear John, >> >> What you describe resembles an azimuth sundial. See for >> instance the >> Plochingen sundial in Karl Schwarzinger's collection: >> http://members.aon.at/sundials/bild44_e.htm >> In this case, there would be no clear-cut alignment with >> anything, >> including the (in)famous path... >> >> Best regards, >> Frans >> www.fransmaes.nl/sundials --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Advice wanted, on 'Analemmatic' sundial orientation
Dear John,
What you describe resembles an azimuth sundial. See for instance the
Plochingen sundial in Karl Schwarzinger's collection:
http://members.aon.at/sundials/bild44_e.htm
In this case, there would be no clear-cut alignment with anything,
including the (in)famous path...
Best regards,
Frans
www.fransmaes.nl/sundials
[EMAIL PROTECTED] wrote:
> Forgive me, for returning with yet another tiresome proposal:
>
> On reflection I suspect Mr Phillips may not be totally wrong-headed.
> On any one day the azimuth of the shadow of a static human
> shadow-caster can be marked by a circular arc of hour-marks or indeed
> by hour-marks fixed along two straight lines parallel to Mr Phillips'
> driveway.
>
> This arrangement would be accurate on only two days each year. But
> it would be a simple matter to move all the hour-marks (except the
> noon-marker) say once a week, or less frequently at the solstices
> when Kentwell Hall might be busiest. Anyone on this mailing list
> could print off the necessary page of solar azimuths, or preferably
> shadow azimuths, at weekly intervals.
>
> So I would envisage a single spot, perhaps in the middle of a
> decorative compass rose, for the shadow caster to stand on. The
> human gnomon might be at the centre of a circle of, say, 360
> identical bricks, at 1-degree intervals. The print-out would tell Mr
> Phillips which brick should hold each hour-mark for the current week;
> it could painlessly incorporate the equation of time and daylight
> saving.
>
> No self-respecting diallist could be happy with this proposal, but it
> does seem to meet most of Mr Phillips' criteria for a human sundial,
> albeit no longer analemmatic.
>
> John Lynes
>
>
>>> -Original Message-From:
>> [EMAIL PROTECTED]
>>> [mailto:[EMAIL PROTECTED]
>>>
>>> Dear Sundial Experts, I have recently joined this Mailing List,
>>> and hope
>> that any members will be
>>> able to give me some assistance on the following
>> situation.
>>> Our local Stately Home ("Kentwell Hall",
>> Long Melford, Suffolk) is
>>> considering installing an Analemmatic sundial, as a
>> new interactive
>>> attraction for visitors - but we are getting
>> 'conflicting' advice, on
>>> whether this 'Human Sundial' will work in the
>> way we want it to. We have
>>> been in discussion with "Modern Sunclocks"
>> (apparently the acknowledged
>>> 'experts' for these features), who have told
>> us that its central scale of
>>> dates must be aligned North/South - plus that hour
>> markers must be correctly
>>> positioned on an elliptical ring, and which would lie
>> on the Northern side
>>> of that scale of dates. Photographs on their website (
>>> www.sunclocks.com )
>> confirm this.
>>> However, our 'Director of Operations' (Mr
>> Phillips) absolutelyINSISTS that
>>> he wants the scale to run exactly parallel with
>> ourmain driveway - on a
>>> compass bearing which is about 162 degreesfrom North,
>> with the hour points
>>> placed on its Southern side.He also wants the hour
>> points to form an exact
>>> semi-circle, andnot be elliptical in shape. Mr
>> Phillips refuses to accept
>>> thathe cannot arbitrarily position the Human Sundial
>> feature as hewishes,
>>> and says that it must be possible to create this so
>> thatit could then align
>>> with the existing layout of buildings/paths. Can anyone on this
>>> Mailing List tell me whether it is
>> possible toinstall a
>>> Human Sundial to fit any existing orientations,
>> (withappropriate
>>> re-calculation of its component parts) - or, if
>> not,just confirm that it
>>> must be as "Modern Sunclocks" have told me. I can then show the
>>> 'weight of evidence' to Mr
>> Phillips. Because"Kentwell
>>> Hall" is a well-known Stately Home (open to the
>> public),we should not want
>>> to become a 'laughing stock' by installing
>> afeature which does not work -
>>> despite Mr Phillips assurance that"all types of
>> sundial can be adjusted to
>>> work, in any location". Looking forward to all comments (to this
>>> List, or sent
>> privately).
>>> Sincerely, Alison Shields.
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Advice wanted, on 'Analemmatic' sundial orientation
Forgive me, for returning with yet another tiresome proposal:
On reflection I suspect Mr Phillips may not be totally wrong-headed. On any
one day the azimuth of the shadow of a static human shadow-caster can be marked
by a circular arc of hour-marks or indeed by hour-marks fixed along two
straight lines parallel to Mr Phillips' driveway.
This arrangement would be accurate on only two days each year. But it would be
a simple matter to move all the hour-marks (except the noon-marker) say once a
week, or less frequently at the solstices when Kentwell Hall might be busiest.
Anyone on this mailing list could print off the necessary page of solar
azimuths, or preferably shadow azimuths, at weekly intervals.
So I would envisage a single spot, perhaps in the middle of a decorative
compass rose, for the shadow caster to stand on. The human gnomon might be at
the centre of a circle of, say, 360 identical bricks, at 1-degree intervals.
The print-out would tell Mr Phillips which brick should hold each hour-mark for
the current week; it could painlessly incorporate the equation of time and
daylight saving.
No self-respecting diallist could be happy with this proposal, but it does seem
to meet most of Mr Phillips' criteria for a human sundial, albeit no longer
analemmatic.
John Lynes
> > -Original Message-From:
> [EMAIL PROTECTED]
> > [mailto:[EMAIL PROTECTED]
> >
> > Dear Sundial Experts,
> > I have recently joined this Mailing List, and hope
> that any members will
> be
> > able to give me some assistance on the following
> situation.
> > Our local Stately Home ("Kentwell Hall",
> Long Melford, Suffolk) is
> > considering installing an Analemmatic sundial, as a
> new interactive
> > attraction for visitors - but we are getting
> 'conflicting' advice, on
> > whether this 'Human Sundial' will work in the
> way we want it to. We have
> > been in discussion with "Modern Sunclocks"
> (apparently the acknowledged
> > 'experts' for these features), who have told
> us that its central scale of
> > dates must be aligned North/South - plus that hour
> markers must be
> correctly
> > positioned on an elliptical ring, and which would lie
> on the Northern side
> > of that scale of dates.
> > Photographs on their website ( www.sunclocks.com )
> confirm this.
> > However, our 'Director of Operations' (Mr
> Phillips) absolutelyINSISTS that
> > he wants the scale to run exactly parallel with
> ourmain driveway - on a
> > compass bearing which is about 162 degreesfrom North,
> with the hour points
> > placed on its Southern side.He also wants the hour
> points to form an exact
> > semi-circle, andnot be elliptical in shape. Mr
> Phillips refuses to accept
> > thathe cannot arbitrarily position the Human Sundial
> feature as hewishes,
> > and says that it must be possible to create this so
> thatit could then
> align
> > with the existing layout of buildings/paths.
> > Can anyone on this Mailing List tell me whether it is
> possible toinstall a
> > Human Sundial to fit any existing orientations,
> (withappropriate
> > re-calculation of its component parts) - or, if
> not,just confirm that it
> > must be as "Modern Sunclocks" have told me.
> > I can then show the 'weight of evidence' to Mr
> Phillips. Because"Kentwell
> > Hall" is a well-known Stately Home (open to the
> public),we should not want
> > to become a 'laughing stock' by installing
> afeature which does not work -
> > despite Mr Phillips assurance that"all types of
> sundial can be adjusted to
> > work, in any location".
> > Looking forward to all comments (to this List, or sent
> privately).
> > Sincerely, Alison Shields.
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Advice wanted, on 'Analemmatic' sundial orientation
So this could be called "analemmatic shadow plane sundial" perhaps? (Note the date scale must be reversed as well.) -- Jan On Thu, Jun 26, 2008 at 10:37 AM, <[EMAIL PROTECTED]> wrote: > Sorry, folks. As always, Chris Lusby Taylor is right. And as usual I have > egg on my face. I guess it's a privilege to be mentored by such a precise > and patient authority. > > Back to the drawing board. Here's my next proposal: > > Lay out a conventional analemmatic sundial turned through 180 degrees, i.e. > with the noon marker to the south of the calendar line. Surround the sundial > with a circular path, separated from the sundial by a circle of railings. At > the appropriate point on the calendar line place a short upright pole which > could be square in cross-section. > > Tell the visitor to walk around the circular path until his/her shadow falls > in the direction of the pole. Read the time from the analemmatic hour mark > on which the visitor's shadow (not the shadow of the pole) falls. > Cover the bottom few inches of the pole with the retro-reflective material > sold by 3M for road traffic signs. Then, with luck, when the visitor stands > on the right spot and views the pole from the same azimuth as the sun, the > foot of the pole will appear to glow. > > This meets several of Mr Phillips' desiderata. The principal hour markers > will be on the southern side of the dial. He will get his circle or > semi-circle. The dial will use a human gnomon. The pole must be moved each > week along a north/south scale, but the scale itself could be fairly > inconspicuous. Since visitors are not allowed to tread on the sundial face > it can be planted tastefully - maybe in rows parallel to the driveway? > > Now shoot that one down! > > John Lynes --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Advice wanted, on 'Analemmatic' sundial orientation
Sorry, folks. As always, Chris Lusby Taylor is right. And as usual I have egg
on my face. I guess it’s a privilege to be mentored by such a precise and
patient authority.
Back to the drawing board. Here’s my next proposal:
Lay out a conventional analemmatic sundial turned through 180 degrees, i.e.
with the noon marker to the south of the calendar line. Surround the sundial
with a circular path, separated from the sundial by a circle of railings. At
the appropriate point on the calendar line place a short upright pole which
could be square in cross-section.
Tell the visitor to walk around the circular path until his/her shadow falls in
the direction of the pole. Read the time from the analemmatic hour mark on
which the visitor’s shadow (not the shadow of the pole) falls.
Cover the bottom few inches of the pole with the retro-reflective material sold
by 3M for road traffic signs. Then, with luck, when the visitor stands on the
right spot and views the pole from the same azimuth as the sun, the foot of the
pole will appear to glow.
This meets several of Mr Phillips’ desiderata. The principal hour markers will
be on the southern side of the dial. He will get his circle or semi-circle.
The dial will use a human gnomon. The pole must be moved each week along a
north/south scale, but the scale itself could be fairly inconspicuous. Since
visitors are not allowed to tread on the sundial face it can be planted
tastefully - maybe in rows parallel to the driveway?
Now shoot that one down!
John Lynes
--- On Thu, 26/6/08, Chris Lusby Taylor <[EMAIL PROTECTED]> wrote:
> From: Chris Lusby Taylor <[EMAIL PROTECTED]>
> Subject: Re: Advice wanted, on 'Analemmatic' sundial orientation
> To: sundial@uni-koeln.de
> Date: Thursday, 26 June, 2008, 4:25 PM
> I have now proved arithmetically (to my own satisfaction at
> least) that
> there is no dial shape that works like an analemmatic dial
> but with the
> azimuth halved.
>
> I did this by calculating how far the gnomon would have to
> move at 2pm
> between the solstices and the equinoxes, and comparing
> these figures with
> 4pm (for some arbitrary latitude). The ratios are
> different, implying that
> wherever you put a vertical gnomon on these three dates you
> could not
> position both a 2pm and a 4pm marker. For a normal
> analemmatic dial the
> ratios are all 1, i.e. the distance you move the gnomon
> from winter to
> spring = the distance you move it from spring to summer,
> for all hours of
> the day.
>
> Too bad. But I like the 2:1 gearing idea. Mechanisms to do
> this are very
> simple - the top of a pair of compasses is an example.
>
> Chris Lusby Taylor
> 51.4N 1.3W
> > -Original Message-From:
> [EMAIL PROTECTED]
> > [mailto:[EMAIL PROTECTED]
> >
> > Dear Sundial Experts,
> > I have recently joined this Mailing List, and hope
> that any members will
> be
> > able to give me some assistance on the following
> situation.
> > Our local Stately Home ("Kentwell Hall",
> Long Melford, Suffolk) is
> > considering installing an Analemmatic sundial, as a
> new interactive
> > attraction for visitors - but we are getting
> 'conflicting' advice, on
> > whether this 'Human Sundial' will work in the
> way we want it to. We have
> > been in discussion with "Modern Sunclocks"
> (apparently the acknowledged
> > 'experts' for these features), who have told
> us that its central scale of
> > dates must be aligned North/South - plus that hour
> markers must be
> correctly
> > positioned on an elliptical ring, and which would lie
> on the Northern side
> > of that scale of dates.
> > Photographs on their website ( www.sunclocks.com )
> confirm this.
> > However, our 'Director of Operations' (Mr
> Phillips) absolutelyINSISTS that
> > he wants the scale to run exactly parallel with
> ourmain driveway - on a
> > compass bearing which is about 162 degreesfrom North,
> with the hour points
> > placed on its Southern side.He also wants the hour
> points to form an exact
> > semi-circle, andnot be elliptical in shape. Mr
> Phillips refuses to accept
> > thathe cannot arbitrarily position the Human Sundial
> feature as hewishes,
> > and says that it must be possible to create this so
> thatit could then
> align
> > with the existing layout of buildings/paths.
> > Can anyone on this Mailing List tell me whether it is
> possible toinstall a
> > Human Sundial to fit any existing orientations,
> (withappropriate
> > re-calculation of its component parts) - or, if
> not,just confirm that it
> > must be as "Modern Sunclocks" hav
Re: Advice wanted, on 'Analemmatic' sundial orientation
I have now proved arithmetically (to my own satisfaction at least) that there is no dial shape that works like an analemmatic dial but with the azimuth halved. I did this by calculating how far the gnomon would have to move at 2pm between the solstices and the equinoxes, and comparing these figures with 4pm (for some arbitrary latitude). The ratios are different, implying that wherever you put a vertical gnomon on these three dates you could not position both a 2pm and a 4pm marker. For a normal analemmatic dial the ratios are all 1, i.e. the distance you move the gnomon from winter to spring = the distance you move it from spring to summer, for all hours of the day. Too bad. But I like the 2:1 gearing idea. Mechanisms to do this are very simple - the top of a pair of compasses is an example. Chris Lusby Taylor 51.4N 1.3W - Original Message - From: "Chris Lusby Taylor" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]>; Sent: Wednesday, June 25, 2008 7:01 PM Subject: Re: Advice wanted, on 'Analemmatic' sundial orientation > Very neat John! > > But I don't think it works. Not even if south-facing. > > The problem is that you are halving the angle through which you turn the > dial. That affects the geometry of the elliptical dial. You can't just > renumber the hour marks. The sun's azimuth (measured from south) at 2pm is > not twice the azimuth at 1pm. > So, I'm pretty sure you can't just take an analemmatic ellipse, reverse and > renumber the hours. But maybe there is a shape, perhaps a different ellipse, > that would work. You might well have to change the date scale as well. > > If you can find a shape that works, I have some good news: the hour marks > are unchanged by the realignment of the axis from north-south. Imagine, for > instance, that the path went east-west. The mirror would be at 45 degrees to > the axes of the dial. The rotation of the mirror (and dial) to follow the > sun would be precisely the same as it would for a north-south path, so the > hour marks would still have 12 in the middle and all other angles as before. > > Actually, rather than having the mirror at 45 degrees to the dial's axes and > a north or south pointer to read the time, you could align the dial with the > mirror and turn the pointer 45 degrees. Or, you could have the pointer > mounted with the mirror and the dial on the ground in a fixed orientation > (such as parallel to the infamous path), but able to be slid along its minor > axis according to the date. > The possibilities are almost endless. Or, they would be if we could find a > dial shape that would work! > > But finding a shape that will function as a dial (or even proving that one > exists) will take a little longer than the spare time I have today. Sorry. > If anyone else wants to try it, I suggest tracing the hourly azimuth lines > for the equinoxes overlaid with the same lines for one of the solstices, > assuming the gnomon has moved by some arbitrary distance in the meantime. > Find the dial shape that would work for both dates (there will probably be > one) and see if it will work for all other dates. > > Best wishes > Chris Lusby Taylor > > > - Original Message - > From: "John Lynes" <[EMAIL PROTECTED]> > To: > Sent: Wednesday, June 25, 2008 4:46 PM > Subject: Advice wanted, on 'Analemmatic' sundial orientation > > > I'm grateful for the generous reception you gave to my last contribution to > this thread. Here belatedly is another possible solution, less impractical > but more complex than my last effort. > > Imagine a North-South meridian line on flat ground. On this line place a > thin flat vertical mirror - essentially a vertical reflective slit - a few > feet above the ground and pivoted to rotate about a vertical axis through > the mirror and the meridian. When the sun shines, a visitor is asked to > turn the mirrored slit so that the sun's reflection falls along the meridian > line. > > Straight below the slit, locked to the same vertical axis, is a small > horizontal analemmatic sundial, a few inches across, placed so that the axis > of rotation of the assembly coincides with the calendar date-point on the > analemmatic dial, and the major axis of the analemmatic dial's ellipse is > parallel to the plane of the mirror. The direction of the meridian line > indicates the solar time on the (modified, see below) face of the > analemmatic dial. > > The azimuth of the mirror, measured from the meridian, would be only half > the azimuth of the sun, so the hour markings on the analemmatic dial would > need adjusting, e.g. the 1pm mark would be relabelled 2pm (sorry, 10.am). > They would run anti-clockwise, and woul
Re: Advice wanted, on 'Analemmatic' sundial orientation
On Wed, Jun 25, 2008 at 11:01 AM, Chris Lusby Taylor <[EMAIL PROTECTED]> wrote: > Very neat John! > > But I don't think it works. Not even if south-facing. > > The problem is that you are halving the angle through which you turn the > dial. That affects the geometry of the elliptical dial. You can't just > renumber the hour marks. The sun's azimuth (measured from south) at 2pm is > not twice the azimuth at 1pm. > So, I'm pretty sure you can't just take an analemmatic ellipse, reverse and > renumber the hours. But maybe there is a shape, perhaps a different ellipse, > that would work. You might well have to change the date scale as well. John's neat idea rearranges things as if the Sun during the day moved only up and down along the celestial meridian while the missing azimuthal motion is done by the sundial itself. As Chris points out, the dial cannot be rigidly fixed to the mirror since the mirror only moves through half the required azimuth. So one way to fix this small problem is to rotate the sundial twice as fast as the mirror - perhaps have them connected by some simple 2:1 gearing mechanism. -- Jan --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Advice wanted, on 'Analemmatic' sundial orientation
Very neat John!
But I don't think it works. Not even if south-facing.
The problem is that you are halving the angle through which you turn the
dial. That affects the geometry of the elliptical dial. You can't just
renumber the hour marks. The sun's azimuth (measured from south) at 2pm is
not twice the azimuth at 1pm.
So, I'm pretty sure you can't just take an analemmatic ellipse, reverse and
renumber the hours. But maybe there is a shape, perhaps a different ellipse,
that would work. You might well have to change the date scale as well.
If you can find a shape that works, I have some good news: the hour marks
are unchanged by the realignment of the axis from north-south. Imagine, for
instance, that the path went east-west. The mirror would be at 45 degrees to
the axes of the dial. The rotation of the mirror (and dial) to follow the
sun would be precisely the same as it would for a north-south path, so the
hour marks would still have 12 in the middle and all other angles as before.
Actually, rather than having the mirror at 45 degrees to the dial's axes and
a north or south pointer to read the time, you could align the dial with the
mirror and turn the pointer 45 degrees. Or, you could have the pointer
mounted with the mirror and the dial on the ground in a fixed orientation
(such as parallel to the infamous path), but able to be slid along its minor
axis according to the date.
The possibilities are almost endless. Or, they would be if we could find a
dial shape that would work!
But finding a shape that will function as a dial (or even proving that one
exists) will take a little longer than the spare time I have today. Sorry.
If anyone else wants to try it, I suggest tracing the hourly azimuth lines
for the equinoxes overlaid with the same lines for one of the solstices,
assuming the gnomon has moved by some arbitrary distance in the meantime.
Find the dial shape that would work for both dates (there will probably be
one) and see if it will work for all other dates.
Best wishes
Chris Lusby Taylor
- Original Message -
From: "John Lynes" <[EMAIL PROTECTED]>
To:
Sent: Wednesday, June 25, 2008 4:46 PM
Subject: Advice wanted, on 'Analemmatic' sundial orientation
I'm grateful for the generous reception you gave to my last contribution to
this thread. Here belatedly is another possible solution, less impractical
but more complex than my last effort.
Imagine a North-South meridian line on flat ground. On this line place a
thin flat vertical mirror - essentially a vertical reflective slit - a few
feet above the ground and pivoted to rotate about a vertical axis through
the mirror and the meridian. When the sun shines, a visitor is asked to
turn the mirrored slit so that the sun's reflection falls along the meridian
line.
Straight below the slit, locked to the same vertical axis, is a small
horizontal analemmatic sundial, a few inches across, placed so that the axis
of rotation of the assembly coincides with the calendar date-point on the
analemmatic dial, and the major axis of the analemmatic dial's ellipse is
parallel to the plane of the mirror. The direction of the meridian line
indicates the solar time on the (modified, see below) face of the
analemmatic dial.
The azimuth of the mirror, measured from the meridian, would be only half
the azimuth of the sun, so the hour markings on the analemmatic dial would
need adjusting, e.g. the 1pm mark would be relabelled 2pm (sorry, 10.am).
They would run anti-clockwise, and would of course be reversed from north to
south.
A groundsman would have to keep the mirror polished, and realign the
date-point with the axis of rotation perhaps once a week. He might fix a
different dial for daylight saving.
Now comes the nifty bit! Mr Phillips is not forced to accept a North-South
meridian line. He could commission a line parallel to his main driveway,
for aligning the reflection of the sun. A small fixed North-South marker
would still indicate the time on the analemmatic dial. I leave it to the
heavyweights to recalculate the hourly markings on the dial face.
Alas the gnomon is no longer human, but the device would be interactive,
instructive and, I daresay, unprecedented.
Apologies for a disgracefully late entry!
John Lynes
-Original Message-From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]
Dear Sundial Experts,
I have recently joined this Mailing List, and hope that any members will be
able to give me some assistance on the following situation.
Our local Stately Home ("Kentwell Hall", Long Melford, Suffolk) is
considering installing an Analemmatic sundial, as a new interactive
attraction for visitors - but we are getting 'conflicting' advice, on
whether this 'Human Sundial' will work in the way we want it to. We have
been in discussion with "Modern Sunclocks" (apparently the acknowledged
'experts' for these
Re: Advice wanted, on 'Analemmatic' sundial orientation
Nice job. Original, adaptable. I suspect it can be modified to apply
to a larger scope of dials than just analemmatic. Not sure the public
would go for it aesthetically, but I admire the concept.
-Bill Gottesman
John Lynes wrote:
> I'm grateful for the generous reception you gave to my last contribution to
> this thread. Here belatedly is another possible solution, less impractical
> but more complex than my last effort.
>
> Imagine a North-South meridian line on flat ground. On this line place a
> thin flat vertical mirror - essentially a vertical reflective slit - a few
> feet above the ground and pivoted to rotate about a vertical axis through the
> mirror and the meridian. When the sun shines, a visitor is asked to turn the
> mirrored slit so that the sun's reflection falls along the meridian line.
>
> Straight below the slit, locked to the same vertical axis, is a small
> horizontal analemmatic sundial, a few inches across, placed so that the axis
> of rotation of the assembly coincides with the calendar date-point on the
> analemmatic dial, and the major axis of the analemmatic dial's ellipse is
> parallel to the plane of the mirror. The direction of the meridian line
> indicates the solar time on the (modified, see below) face of the analemmatic
> dial.
>
> The azimuth of the mirror, measured from the meridian, would be only half the
> azimuth of the sun, so the hour markings on the analemmatic dial would need
> adjusting, e.g. the 1pm mark would be relabelled 2pm (sorry, 10.am). They
> would run anti-clockwise, and would of course be reversed from north to south.
>
> A groundsman would have to keep the mirror polished, and realign the
> date-point with the axis of rotation perhaps once a week. He might fix a
> different dial for daylight saving.
>
> Now comes the nifty bit! Mr Phillips is not forced to accept a North-South
> meridian line. He could commission a line parallel to his main driveway, for
> aligning the reflection of the sun. A small fixed North-South marker would
> still indicate the time on the analemmatic dial. I leave it to the
> heavyweights to recalculate the hourly markings on the dial face.
>
> Alas the gnomon is no longer human, but the device would be interactive,
> instructive and, I daresay, unprecedented.
>
> Apologies for a disgracefully late entry!
>
> John Lynes
>
>
> -Original Message-From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
>
> Dear Sundial Experts,
> I have recently joined this Mailing List, and hope that any members will be
> able to give me some assistance on the following situation.
> Our local Stately Home ("Kentwell Hall", Long Melford, Suffolk) is
> considering installing an Analemmatic sundial, as a new interactive
> attraction for visitors - but we are getting 'conflicting' advice, on whether
> this 'Human Sundial' will work in the way we want it to. We have been in
> discussion with "Modern Sunclocks" (apparently the acknowledged 'experts' for
> these features), who have told us that its central scale of dates must be
> aligned North/South - plus that hour markers must be correctly positioned on
> an elliptical ring, and which would lie on the Northern side of that scale of
> dates.
> Photographs on their website ( www.sunclocks.com ) confirm this.
> However, our 'Director of Operations' (Mr Phillips) absolutelyINSISTS that he
> wants the scale to run exactly parallel with ourmain driveway - on a compass
> bearing which is about 162 degreesfrom North, with the hour points placed on
> its Southern side.He also wants the hour points to form an exact semi-circle,
> andnot be elliptical in shape. Mr Phillips refuses to accept thathe cannot
> arbitrarily position the Human Sundial feature as hewishes, and says that it
> must be possible to create this so thatit could then align with the existing
> layout of buildings/paths.
> Can anyone on this Mailing List tell me whether it is possible toinstall a
> Human Sundial to fit any existing orientations, (withappropriate
> re-calculation of its component parts) - or, if not,just confirm that it must
> be as "Modern Sunclocks" have told me.
> I can then show the 'weight of evidence' to Mr Phillips. Because"Kentwell
> Hall" is a well-known Stately Home (open to the public),we should not want to
> become a 'laughing stock' by installing afeature which does not work -
> despite Mr Phillips assurance that"all types of sundial can be adjusted to
> work, in any location".
> Looking forward to all comments (to this List, or sent privately).
> Sincerely, Alison Shields.
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
>
>
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
Advice wanted, on 'Analemmatic' sundial orientation
I'm grateful for the generous reception you gave to my last contribution to
this thread. Here belatedly is another possible solution, less impractical but
more complex than my last effort.
Imagine a North-South meridian line on flat ground. On this line place a thin
flat vertical mirror - essentially a vertical reflective slit - a few feet
above the ground and pivoted to rotate about a vertical axis through the mirror
and the meridian. When the sun shines, a visitor is asked to turn the mirrored
slit so that the sun's reflection falls along the meridian line.
Straight below the slit, locked to the same vertical axis, is a small
horizontal analemmatic sundial, a few inches across, placed so that the axis of
rotation of the assembly coincides with the calendar date-point on the
analemmatic dial, and the major axis of the analemmatic dial's ellipse is
parallel to the plane of the mirror. The direction of the meridian line
indicates the solar time on the (modified, see below) face of the analemmatic
dial.
The azimuth of the mirror, measured from the meridian, would be only half the
azimuth of the sun, so the hour markings on the analemmatic dial would need
adjusting, e.g. the 1pm mark would be relabelled 2pm (sorry, 10.am). They
would run anti-clockwise, and would of course be reversed from north to south.
A groundsman would have to keep the mirror polished, and realign the date-point
with the axis of rotation perhaps once a week. He might fix a different dial
for daylight saving.
Now comes the nifty bit! Mr Phillips is not forced to accept a North-South
meridian line. He could commission a line parallel to his main driveway, for
aligning the reflection of the sun. A small fixed North-South marker would
still indicate the time on the analemmatic dial. I leave it to the
heavyweights to recalculate the hourly markings on the dial face.
Alas the gnomon is no longer human, but the device would be interactive,
instructive and, I daresay, unprecedented.
Apologies for a disgracefully late entry!
John Lynes
-Original Message-From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Dear Sundial Experts,
I have recently joined this Mailing List, and hope that any members will be
able to give me some assistance on the following situation.
Our local Stately Home ("Kentwell Hall", Long Melford, Suffolk) is considering
installing an Analemmatic sundial, as a new interactive attraction for visitors
- but we are getting 'conflicting' advice, on whether this 'Human Sundial' will
work in the way we want it to. We have been in discussion with "Modern
Sunclocks" (apparently the acknowledged 'experts' for these features), who have
told us that its central scale of dates must be aligned North/South - plus that
hour markers must be correctly positioned on an elliptical ring, and which
would lie on the Northern side of that scale of dates.
Photographs on their website ( www.sunclocks.com ) confirm this.
However, our 'Director of Operations' (Mr Phillips) absolutelyINSISTS that he
wants the scale to run exactly parallel with ourmain driveway - on a compass
bearing which is about 162 degreesfrom North, with the hour points placed on
its Southern side.He also wants the hour points to form an exact semi-circle,
andnot be elliptical in shape. Mr Phillips refuses to accept thathe cannot
arbitrarily position the Human Sundial feature as hewishes, and says that it
must be possible to create this so thatit could then align with the existing
layout of buildings/paths.
Can anyone on this Mailing List tell me whether it is possible toinstall a
Human Sundial to fit any existing orientations, (withappropriate re-calculation
of its component parts) - or, if not,just confirm that it must be as "Modern
Sunclocks" have told me.
I can then show the 'weight of evidence' to Mr Phillips. Because"Kentwell
Hall" is a well-known Stately Home (open to the public),we should not want to
become a 'laughing stock' by installing afeature which does not work - despite
Mr Phillips assurance that"all types of sundial can be adjusted to work, in any
location".
Looking forward to all comments (to this List, or sent privately). Sincerely,
Alison Shields.
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Advice wanted, on 'Analemmatic' sundial orientation
Hi All again,
Just to clarify John and Hendrik's suggestions:
- with a non-south-facing vertical mirror you can turn the axis of the date
scale and the dial ellipse to align with the path, so 12 noon will be due south
of the centre of the dial (requrement 1). But note that the mirror itself would
not be aligned with the path. The mirror can be placed just north of the date
scale which, by the way would have June/July at its southern end - the reverse
of normal. Or, the mirror could be moveable, sliding along the date scale. This
would allow a smaller mirror. Otherwise, it would have to be very big indeed.
- with a south-facing non-vertical mirror you can make the scale circular, not
elliptical, but 12 noon will not be due south of the centre of the dial
(requirement 2). The date scale is not needed - you always stand in the same
spot. The mirror can be smaller and non-moveable.
What you cannot do is both requirements together with a single mirror. You
could perhaps, in theory, do it with two vast mirrors, but the dial would be
hidden in between them, so the feature visitors would see first would be the
mirrors, not the dial, and the benefit of having the dial aligned with the path
would be lost.
You, or Mr Phillips, would have to decide whether you want the dial to be
circular or to be aligned with the path.
With both types, there's a small problem that should be mentioned - that there
will be two shadows! Let's say you stand with your back to a mirror and that
the sun is in front and to the right of you. The direct sunlight falling on
your right cheek will not reach the mirror, so will cause a shadow to appear on
the ground in front of you. Also, the sunlight that reflects off the mirror
onto the back of your head will cause a shadow. So, you will see two shadows.
Which is telling the time?
With a vertical mirror the shadows are parallel. One appears to touch your feet
directly - not via the mirror. That's the one to use.
With a reclining mirror, I think it should be placed right next to where you
stand. One of the shadows will similarly appear to touch your own feet. It's
also longer than the other. This is the one to use. But I have to confess that
having two shadows could be very confusing. By the way, rather than reading the
time on the physical dial, you could read it in the mirror. The hour marks
would have to be mirror images of normal numbers, of course. Even in the mirror
you can still see two shadows, unless you're a vampire.
To make the shadows easier to see I would suggest somehow shielding the hour
marks from direct sunlight. Put something just south of them.
My preference, for what it's worth, would be to use John Lynes' inclined
mirror. I think this would create a very striking semicircular feature. Indeed,
it may well be unique in the world, unless John has used it elsewhere. One
further feature it might be possible to incorporate would be to make the hour
marks moveable so that they could be turned 15 degrees in summer to show BST.
That's not possible with most sundials as the hour line angles aren't all 15
degrees, but with this one they are.
By the way, with an analemmatic sundial that uses a human shadow, one decision
is how big to make it. An noon in midsummer the sun's altitude is 62 degrees
and one's shadow is less than three feet. It's a mistake to make the dial too
big. But the reclining mirror effectively reduces the sun's altitude to just 23
degrees so the shadow is greatly elongated and the dial can be made much bigger.
Hope this helps
Chris Lusby Taylor
51.4N 1.3W
- Original Message -
From: Analemma Zonnewijzers
To: Chris Lusby Taylor ; John Carmichael ; [EMAIL PROTECTED] ; [EMAIL
PROTECTED] ; sundial@uni-koeln.de
Sent: Tuesday, June 10, 2008 8:27 AM
Subject: Re: Advice wanted, on 'Analemmatic' sundial orientation
Hi All,
very interesting issue, so after all:
with a verticle mirror with the right azimut you could turn the famous
analemmatic sundial so the the line with the dates is on a path which is not
north-south! and the ellips will be alligned with this path
looks to me that the issue can be solved after all.
One has to investigate if the dimensions of the mirror are realistic and you
will need 2 mirrors (or 2 sundials) to cover the whole 24 hours .
If the azimut of the path is alpha, the mirror should be at alpha/2,
kind regards,
Hendrik
-
Analemma Sundials
H J Hollander
Fixed +31 20 6374383
Cell +31 616 462 879
[EMAIL PROTECTED]
www.analemma.biz
lat 52 23' long 4 57'
- Original Message -
From: Chris Lusby Taylor
To: John Carmichael ; [EMAIL PROTECTED] ; [EMAIL PROTECTED] ;
sundial@uni-koeln.de
Sent: Monday, June 09, 2008 7:38 PM
Subject: [SPAM]Re: Advice wanted, on 'Analemmatic
Re: Advice wanted, on 'Analemmatic' sundial orientation
Hi All,
very interesting issue, so after all:
with a verticle mirror with the right azimut you could turn the famous
analemmatic sundial so the the line with the dates is on a path which is not
north-south! and the ellips will be alligned with this path
looks to me that the issue can be solved after all.
One has to investigate if the dimensions of the mirror are realistic and you
will need 2 mirrors (or 2 sundials) to cover the whole 24 hours .
If the azimut of the path is alpha, the mirror should be at alpha/2,
kind regards,
Hendrik
-
Analemma Sundials
H J Hollander
Fixed +31 20 6374383
Cell +31 616 462 879
[EMAIL PROTECTED]
www.analemma.biz
lat 52 23' long 4 57'
- Original Message -
From: Chris Lusby Taylor
To: John Carmichael ; [EMAIL PROTECTED] ; [EMAIL PROTECTED] ;
sundial@uni-koeln.de
Sent: Monday, June 09, 2008 7:38 PM
Subject: [SPAM]Re: Advice wanted, on 'Analemmatic' sundial orientation
Hi John et al,
I thought at first that John Lynes was making a joke, but you could actually
do this. If you have a large, fixed, plane mirror you can use the sunlight
reflected off it instead of the actual sun. By suitably angling the mirror you
can make the sun appear to rotate about any desired axis, not just the earth's
axis. So, you can make it appear to rotate about the local vertical, just as it
does at the Poles. So, just as at the Poles, an analemmatic sundial using the
reflected light will be circular and the gnomon/person will not need to be
moved for different seasons. But the numbers will go round anticlockwise, which
might cause further objections!
The actual angle you'd need is this, I think: take a vertical mirror, facing
south, then lean it towards the north at (90+latitude)/2 to the horizontal. For
40 degrees North this makes 65 degrees. So, it's facing the southern sky, as it
were. If it were a dialface we'd say it was a direct south reclining dial. Fix
it there. Now, put a vertical gnomon close to the bottom centre of the mirror
and mark out a perfectly semicircular, equiangular dial around it. It will work
from 6am to 6pm throughout the summer. Or, if you want the user to be the
gnomon, just mark the spot where they must stand.
In the winter months, as John said, the sun's too low in the sky for the
reflection to shine on the ground.
A mirror of, say, four feet high and eight feet wide would work well. It
doesn't have to be 100% perfect optical quality. Users should back up to it to
avoid being dazzled, I suggest. I think this is an excellent solution to what
at first appeared an impossible brief.
Regards
Chris
- Original Message -
From: John Carmichael
To: [EMAIL PROTECTED] ; [EMAIL PROTECTED] ; sundial@uni-koeln.de
Sent: Monday, June 09, 2008 3:42 PM
Subject: RE: Advice wanted, on 'Analemmatic' sundial orientation
Hello John L.
I’ve never heard of such a sundial and I can’t imagine how it would
function. I’m not sure I understand the setup and positioning of the mirror.
Is the mirror permanently fastened to the ground or is the mirror moveable?
Does the mirror reflect sunlight onto the sundial face, or do you read the
sundial by looking at the face’s reflection in the mirror? I just don’t get
it. It sure would be helpful to see a drawing if possible.
Puzzled in Tucson
John C.
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL
PROTECTED]
Sent: Monday, June 09, 2008 4:08 AM
To: [EMAIL PROTECTED]; sundial@uni-koeln.de
Subject: RE: Advice wanted, on 'Analemmatic' sundial orientation
Dear Alison
One expedient, at least in theory, would be to fix a plane mirror,
suitably angled in plan to the main driveway and tilted to convert the
analemmatic sundial ellipse into a circle. The position of the human gnomon
would not vary with the season. The sundial would receive reflected sunlight
only on six months of the year, during the summer months, but this is when most
visitors would be around.
Unfortunately you would need either an enormous mirror or a very
modest analemmatic sundial.
John Lynes
-Original Message-From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Alison ShieldsSent: 03 June 2008 18:57To: [EMAIL PROTECTED]: Advice
wanted, on 'Analemmatic' sundial orientation Dear Sundial Experts, I have
recently joined this Mailing List, and hope that any memberswill be able to
give me some assistance on the following situation. Our local Stately Home
("Kentwell Hall", Long Melford, Suffolk) isconsidering installing an
Analemmatic sundial, as a new interactiveattraction for visitors - but we are
getting 'conflicting' advice,on whethe
RE: Advice wanted, on 'Analemmatic' sundial orientation
This is getting interesting! I now understand the mirror setup, dial face
design and function. So you would make design the sundial face to be an
analemmatic dial for the North Pole (even though it is not located at the North
Pole). It makes sense because we all know that an analemmatic sundial face
collapses into an equatorial face at the North Pole.
Cudos to John Lynes for dreaming up this contraption! The people on our
Sundial List still surprise me after all these years.
Thanks Chris for your great interpretation and analysis.
John C.
From: Chris Lusby Taylor [mailto:[EMAIL PROTECTED]
Sent: Monday, June 09, 2008 10:38 AM
To: John Carmichael; [EMAIL PROTECTED]; [EMAIL PROTECTED]; sundial@uni-koeln.de
Subject: Re: Advice wanted, on 'Analemmatic' sundial orientation
Hi John et al,
I thought at first that John Lynes was making a joke, but you could actually do
this. If you have a large, fixed, plane mirror you can use the sunlight
reflected off it instead of the actual sun. By suitably angling the mirror you
can make the sun appear to rotate about any desired axis, not just the earth's
axis. So, you can make it appear to rotate about the local vertical, just as it
does at the Poles. So, just as at the Poles, an analemmatic sundial using the
reflected light will be circular and the gnomon/person will not need to be
moved for different seasons. But the numbers will go round anticlockwise, which
might cause further objections!
The actual angle you'd need is this, I think: take a vertical mirror, facing
south, then lean it towards the north at (90+latitude)/2 to the horizontal. For
40 degrees North this makes 65 degrees. So, it's facing the southern sky, as it
were. If it were a dialface we'd say it was a direct south reclining dial. Fix
it there. Now, put a vertical gnomon close to the bottom centre of the mirror
and mark out a perfectly semicircular, equiangular dial around it. It will work
from 6am to 6pm throughout the summer. Or, if you want the user to be the
gnomon, just mark the spot where they must stand.
In the winter months, as John said, the sun's too low in the sky for the
reflection to shine on the ground.
A mirror of, say, four feet high and eight feet wide would work well. It
doesn't have to be 100% perfect optical quality. Users should back up to it to
avoid being dazzled, I suggest. I think this is an excellent solution to what
at first appeared an impossible brief.
Regards
Chris
- Original Message -
From: John Carmichael <mailto:[EMAIL PROTECTED]>
To: [EMAIL PROTECTED] ; [EMAIL PROTECTED] ; sundial@uni-koeln.de
Sent: Monday, June 09, 2008 3:42 PM
Subject: RE: Advice wanted, on 'Analemmatic' sundial orientation
Hello John L.
I’ve never heard of such a sundial and I can’t imagine how it would function.
I’m not sure I understand the setup and positioning of the mirror. Is the
mirror permanently fastened to the ground or is the mirror moveable? Does the
mirror reflect sunlight onto the sundial face, or do you read the sundial by
looking at the face’s reflection in the mirror? I just don’t get it. It sure
would be helpful to see a drawing if possible.
Puzzled in Tucson
John C.
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED]
Sent: Monday, June 09, 2008 4:08 AM
To: [EMAIL PROTECTED]; sundial@uni-koeln.de
Subject: RE: Advice wanted, on 'Analemmatic' sundial orientation
Dear Alison
One expedient, at least in theory, would be to fix a plane mirror, suitably
angled in plan to the main driveway and tilted to convert the analemmatic
sundial ellipse into a circle. The position of the human gnomon would not vary
with the season. The sundial would receive reflected sunlight only on six
months of the year, during the summer months, but this is when most visitors
would be around.
Unfortunately you would need either an enormous mirror or a very modest
analemmatic sundial.
John Lynes
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
On Behalf Of Alison Shields
Sent: 03 June 2008 18:57
To: sundial@uni-koeln.de
Subject: Advice wanted, on 'Analemmatic' sundial orientation
Dear Sundial Experts,
I have recently joined this Mailing List, and hope that any members
will be able to give me some assistance on the following situation.
Our local Stately Home ("Kentwell Hall", Long Melford, Suffolk) is
considering installing an Analemmatic sundial, as a new interactive
attraction for visitors - but we are getting 'conflicting' advice,
on whether this 'Human Sundial' will work in the way we want it to.
We have been in discussion with "Modern Sunclocks" (apparently the
acknowledged 'experts' for these features), who have told us that
its central scale of dates must be aligne
Re: Advice wanted, on 'Analemmatic' sundial orientation
Hi John et al,
I thought at first that John Lynes was making a joke, but you could actually do
this. If you have a large, fixed, plane mirror you can use the sunlight
reflected off it instead of the actual sun. By suitably angling the mirror you
can make the sun appear to rotate about any desired axis, not just the earth's
axis. So, you can make it appear to rotate about the local vertical, just as it
does at the Poles. So, just as at the Poles, an analemmatic sundial using the
reflected light will be circular and the gnomon/person will not need to be
moved for different seasons. But the numbers will go round anticlockwise, which
might cause further objections!
The actual angle you'd need is this, I think: take a vertical mirror, facing
south, then lean it towards the north at (90+latitude)/2 to the horizontal. For
40 degrees North this makes 65 degrees. So, it's facing the southern sky, as it
were. If it were a dialface we'd say it was a direct south reclining dial. Fix
it there. Now, put a vertical gnomon close to the bottom centre of the mirror
and mark out a perfectly semicircular, equiangular dial around it. It will work
from 6am to 6pm throughout the summer. Or, if you want the user to be the
gnomon, just mark the spot where they must stand.
In the winter months, as John said, the sun's too low in the sky for the
reflection to shine on the ground.
A mirror of, say, four feet high and eight feet wide would work well. It
doesn't have to be 100% perfect optical quality. Users should back up to it to
avoid being dazzled, I suggest. I think this is an excellent solution to what
at first appeared an impossible brief.
Regards
Chris
- Original Message -
From: John Carmichael
To: [EMAIL PROTECTED] ; [EMAIL PROTECTED] ; sundial@uni-koeln.de
Sent: Monday, June 09, 2008 3:42 PM
Subject: RE: Advice wanted, on 'Analemmatic' sundial orientation
Hello John L.
I’ve never heard of such a sundial and I can’t imagine how it would function.
I’m not sure I understand the setup and positioning of the mirror. Is the
mirror permanently fastened to the ground or is the mirror moveable? Does the
mirror reflect sunlight onto the sundial face, or do you read the sundial by
looking at the face’s reflection in the mirror? I just don’t get it. It sure
would be helpful to see a drawing if possible.
Puzzled in Tucson
John C.
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL
PROTECTED]
Sent: Monday, June 09, 2008 4:08 AM
To: [EMAIL PROTECTED]; sundial@uni-koeln.de
Subject: RE: Advice wanted, on 'Analemmatic' sundial orientation
Dear Alison
One expedient, at least in theory, would be to fix a plane mirror,
suitably angled in plan to the main driveway and tilted to convert the
analemmatic sundial ellipse into a circle. The position of the human gnomon
would not vary with the season. The sundial would receive reflected sunlight
only on six months of the year, during the summer months, but this is when most
visitors would be around.
Unfortunately you would need either an enormous mirror or a very modest
analemmatic sundial.
John Lynes
-Original Message-From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Alison ShieldsSent: 03 June 2008 18:57To: [EMAIL PROTECTED]: Advice
wanted, on 'Analemmatic' sundial orientation Dear Sundial Experts, I have
recently joined this Mailing List, and hope that any memberswill be able to
give me some assistance on the following situation. Our local Stately Home
("Kentwell Hall", Long Melford, Suffolk) isconsidering installing an
Analemmatic sundial, as a new interactiveattraction for visitors - but we are
getting 'conflicting' advice,on whether this 'Human Sundial' will work in the
way we want it to. We have been in discussion with "Modern Sunclocks"
(apparently theacknowledged 'experts' for these features), who have told us
thatits central scale of dates must be aligned North/South - plus thathour
markers must be correctly positioned on an elliptical ring,and which would lie
on the Northern side of that scale of dates. Photographs on their website (
www.sunclocks.com ) confirm this. However, our 'Director of Operations' (Mr
Phillips) absolutelyINSISTS that he wants the scale to run exactly parallel
with ourmain driveway - on a compass bearing which is about 162 degreesfrom
North, with the hour points placed on its Southern side. He also wants the hour
points to form an exact semi-circle, andnot be elliptical in shape. Mr
Phillips refuses to accept thathe cannot arbitrarily position the Human Sundial
feature as hewishes, and says that it must be possible to create this so thatit
could then align with the existing layout of buildings/paths. Can
RE: Advice wanted, on 'Analemmatic' sundial orientation
Hello John L.
I’ve never heard of such a sundial and I can’t imagine how it would function.
I’m not sure I understand the setup and positioning of the mirror. Is the
mirror permanently fastened to the ground or is the mirror moveable? Does the
mirror reflect sunlight onto the sundial face, or do you read the sundial by
looking at the face’s reflection in the mirror? I just don’t get it. It sure
would be helpful to see a drawing if possible.
Puzzled in Tucson
John C.
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED]
Sent: Monday, June 09, 2008 4:08 AM
To: [EMAIL PROTECTED]; sundial@uni-koeln.de
Subject: RE: Advice wanted, on 'Analemmatic' sundial orientation
Dear Alison
One expedient, at least in theory, would be to fix a plane mirror, suitably
angled in plan to the main driveway and tilted to convert the analemmatic
sundial ellipse into a circle. The position of the human gnomon would not vary
with the season. The sundial would receive reflected sunlight only on six
months of the year, during the summer months, but this is when most visitors
would be around.
Unfortunately you would need either an enormous mirror or a very modest
analemmatic sundial.
John Lynes
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
On Behalf Of Alison Shields
Sent: 03 June 2008 18:57
To: sundial@uni-koeln.de
Subject: Advice wanted, on 'Analemmatic' sundial orientation
Dear Sundial Experts,
I have recently joined this Mailing List, and hope that any members
will be able to give me some assistance on the following situation.
Our local Stately Home ("Kentwell Hall", Long Melford, Suffolk) is
considering installing an Analemmatic sundial, as a new interactive
attraction for visitors - but we are getting 'conflicting' advice,
on whether this 'Human Sundial' will work in the way we want it to.
We have been in discussion with "Modern Sunclocks" (apparently the
acknowledged 'experts' for these features), who have told us that
its central scale of dates must be aligned North/South - plus that
hour markers must be correctly positioned on an elliptical ring,
and which would lie on the Northern side of that scale of dates.
Photographs on their website ( www.sunclocks.com ) confirm this.
However, our 'Director of Operations' (Mr Phillips) absolutely
INSISTS that he wants the scale to run exactly parallel with our
main driveway - on a compass bearing which is about 162 degrees
from North, with the hour points placed on its Southern side.
He also wants the hour points to form an exact semi-circle, and
not be elliptical in shape. Mr Phillips refuses to accept that
he cannot arbitrarily position the Human Sundial feature as he
wishes, and says that it must be possible to create this so that
it could then align with the existing layout of buildings/paths.
Can anyone on this Mailing List tell me whether it is possible to
install a Human Sundial to fit any existing orientations, (with
appropriate re-calculation of its component parts) - or, if not,
just confirm that it must be as "Modern Sunclocks" have told me.
I can then show the 'weight of evidence' to Mr Phillips. Because
"Kentwell Hall" is a well-known Stately Home (open to the public),
we should not want to become a 'laughing stock' by installing a
feature which does not work - despite Mr Phillips assurance that
"all types of sundial can be adjusted to work, in any location".
Looking forward to all comments (to this List, or sent privately).
Sincerely,
Alison Shields.
---
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RE: Advice wanted, on 'Analemmatic' sundial orientation
Dear Alison
One expedient, at least in theory, would be to fix a plane mirror,
suitably angled in plan to the main driveway and tilted to convert the
analemmatic sundial ellipse into a circle. The position of the human
gnomon would not vary with the season. The sundial would receive
reflected sunlight only on six months of the year, during the summer months,
but this is when most visitors would be around.
Unfortunately you would need either an enormous mirror or a very modest
analemmatic sundial.
John Lynes
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
On Behalf Of Alison Shields
Sent: 03 June 2008 18:57
To: sundial@uni-koeln.de
Subject: Advice wanted, on 'Analemmatic' sundial orientation
Dear Sundial Experts,
I have recently joined this Mailing List, and hope that any members
will be able to give me some assistance on the following situation.
Our local Stately Home ("Kentwell Hall", Long Melford, Suffolk) is
considering installing an Analemmatic sundial, as a new interactive
attraction for visitors - but we are getting 'conflicting' advice,
on whether this 'Human Sundial' will work in the way we want it to.
We have been in discussion with "Modern Sunclocks" (apparently the
acknowledged 'experts' for these features), who have told us that
its central scale of dates must be aligned North/South - plus that
hour markers must be correctly positioned on an elliptical ring,
and which would lie on the Northern side of that scale of dates.
Photographs on their website ( www.sunclocks.com ) confirm this.
However, our 'Director of Operations' (Mr Phillips) absolutely
INSISTS that he wants the scale to run exactly parallel with our
main driveway - on a compass bearing which is about 162 degrees
from North, with the hour points placed on its Southern side.
He also wants the hour points to form an exact semi-circle, and
not be elliptical in shape. Mr Phillips refuses to accept that
he cannot arbitrarily position the Human Sundial feature as he
wishes, and says that it must be possible to create this so that
it could then align with the existing layout of buildings/paths.
Can anyone on this Mailing List tell me whether it is possible to
install a Human Sundial to fit any existing orientations, (with
appropriate re-calculation of its component parts) - or, if not,
just confirm that it must be as "Modern Sunclocks" have told me.
I can then show the 'weight of evidence' to Mr Phillips. Because
"Kentwell Hall" is a well-known Stately Home (open to the public),
we should not want to become a 'laughing stock' by installing a
feature which does not work - despite Mr Phillips assurance that
"all types of sundial can be adjusted to work, in any location".
Looking forward to all comments (to this List, or sent privately).
Sincerely,
Alison Shields.
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
__
This email has been scanned by the MessageLabs Email Security System.
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Re: Advice wanted, on 'Analemmatic' sundial orientation
Hi All,
Good point of Fer de Vries.
>>
I have the following suggestions:
- build a spider-sundial. You will have nice circles for the dates. The
place you can stand as a human shadowcasting person can be on the path. If
you place the majority of the hourlines and no horizon lines, the pattern is
not visually related to the north. The marks for the date-circle can by on
the path on the sunny southside . In this way I think the path can feel like
the central axis of the dail. There is only 1 point where you can stand is a
human gnomon. That is a small concession I think.
- an other solution I thought of is one analemma on the path and 1 standing
fixed gnomon beside the path. I we seek a bit I think that there is an
analemma which is aligned with the path for 1 hour. Although you don't have
a human shadow casting person, and there is only 1 hour marked, I think it
will be nice and gives someone the feeling that the sun guides the path.
Kind regards,
Hendrik Hollander
[EMAIL PROTECTED]
www.analemma.biz
lat 52 23' long 4 57'
- Original Message -
From: "fer de vries" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>;
Sent: Wednesday, June 04, 2008 5:12 PM
Subject: Re: Advice wanted, on 'Analemmatic' sundial orientation
> Alison,
>
> Well, you got a number of answers that it won't work, but
>
> Forget the analemmatic sundial and look for a shadowplane or hourplane
> sundial.
> Several of the wanted demands can be realized.
> It is an interactive dial, it has the hourpoints at the south side and the
> hourpoints can be in a circle.
>
> Have a look at our website:
> http://www.de-zonnewijzerkring.nl
> Work of members
> Archives 2003
> Month 03-02
>
> Best wishes, Fer.
>
> Fer J. de Vries
>
> De Zonnewijzerkring
> http://www.de-zonnewijzerkring.nl
>
> Molens
> http://www.collsemolen.dse.nl
>
> Eindhoven, Netherlands
> lat. 51:30 N long. 5:30 E
>
> ----- Original Message -
> From: "Alison Shields" <[EMAIL PROTECTED]>
> To:
> Sent: Tuesday, June 03, 2008 7:57 PM
> Subject: Advice wanted, on 'Analemmatic' sundial orientation
>
>
>>
>> Dear Sundial Experts,
>>
>> I have recently joined this Mailing List, and hope that any members
>> will be able to give me some assistance on the following situation.
>>
>> Our local Stately Home ("Kentwell Hall", Long Melford, Suffolk) is
>> considering installing an Analemmatic sundial, as a new interactive
>> attraction for visitors - but we are getting 'conflicting' advice,
>> on whether this 'Human Sundial' will work in the way we want it to.
>>
>>
>> We have been in discussion with "Modern Sunclocks" (apparently the
>> acknowledged 'experts' for these features), who have told us that
>> its central scale of dates must be aligned North/South - plus that
>> hour markers must be correctly positioned on an elliptical ring,
>> and which would lie on the Northern side of that scale of dates.
>>
>> Photographs on their website ( www.sunclocks.com ) confirm this.
>>
>>
>> However, our 'Director of Operations' (Mr Phillips) absolutely
>> INSISTS that he wants the scale to run exactly parallel with our
>> main driveway - on a compass bearing which is about 162 degrees
>> from North, with the hour points placed on its Southern side.
>>
>> He also wants the hour points to form an exact semi-circle, and
>> not be elliptical in shape. Mr Phillips refuses to accept that
>> he cannot arbitrarily position the Human Sundial feature as he
>> wishes, and says that it must be possible to create this so that
>> it could then align with the existing layout of buildings/paths.
>>
>>
>> Can anyone on this Mailing List tell me whether it is possible to
>> install a Human Sundial to fit any existing orientations, (with
>> appropriate re-calculation of its component parts) - or, if not,
>> just confirm that it must be as "Modern Sunclocks" have told me.
>>
>> I can then show the 'weight of evidence' to Mr Phillips. Because
>> "Kentwell Hall" is a well-known Stately Home (open to the public),
>> we should not want to become a 'laughing stock' by installing a
>> feature which does not work - despite Mr Phillips assurance that
>> "all types of sundial can be adjusted to work, in any location".
>>
>>
>> Looking forward to all comments (to this List, or sent privately).
>>
>>
>> Sincerely,
>>
>> Alison Shields.
>>
>> ---
>> https://lists.uni-koeln.de/mailman/listinfo/sundial
>>
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
RE: Advice wanted, on 'Analemmatic' sundial orientation
> Andrew James wrote: > > > If, instead of standing on the central "month" scale, the user finds and > > stands on or near the hour number which casts his shadow onto the > > appropriate date, the numbers might be arranged to the South rather than > > to the North of the centre. This requires more action on the part of the > > user. > > Best practical suggestion I've seen yet! > It would require making the date line markers visible from a distance, or > possibly a daily (or weekly) placing of a small pylon by facility > personnel. > > > If the hours were not in a horizontal plane, perhaps they could be > > arranged to lie on a semicircle in some other plane - though not, I > > think, what Mr Phillips would like? > > Considering the relatively (to central US) high latitude, it might not be > too extreme. Something like a ramped walkway (semi)encircling the area of > the dial face. I have one doubt. Instead of changing the plane of the hours, could it be possible to change the one of the months? Ricardo --- https://lists.uni-koeln.de/mailman/listinfo/sundial
RE: Advice wanted, on 'Analemmatic' sundial orientation
Andrew James wrote: > If, instead of standing on the central "month" scale, the user finds and > stands on or near the hour number which casts his shadow onto the > appropriate date, the numbers might be arranged to the South rather than > to the North of the centre. This requires more action on the part of the > user. Best practical suggestion I've seen yet! It would require making the date line markers visible from a distance, or possibly a daily (or weekly) placing of a small pylon by facility personnel. > If the hours were not in a horizontal plane, perhaps they could be > arranged to lie on a semicircle in some other plane - though not, I > think, what Mr Phillips would like? Considering the relatively (to central US) high latitude, it might not be too extreme. Something like a ramped walkway (semi)encircling the area of the dial face. Dave --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Advice wanted, on 'Analemmatic' sundial orientation
Alison,
Well, you got a number of answers that it won't work, but
Forget the analemmatic sundial and look for a shadowplane or hourplane
sundial.
Several of the wanted demands can be realized.
It is an interactive dial, it has the hourpoints at the south side and the
hourpoints can be in a circle.
Have a look at our website:
http://www.de-zonnewijzerkring.nl
Work of members
Archives 2003
Month 03-02
Best wishes, Fer.
Fer J. de Vries
De Zonnewijzerkring
http://www.de-zonnewijzerkring.nl
Molens
http://www.collsemolen.dse.nl
Eindhoven, Netherlands
lat. 51:30 N long. 5:30 E
- Original Message -
From: "Alison Shields" <[EMAIL PROTECTED]>
To:
Sent: Tuesday, June 03, 2008 7:57 PM
Subject: Advice wanted, on 'Analemmatic' sundial orientation
>
> Dear Sundial Experts,
>
> I have recently joined this Mailing List, and hope that any members
> will be able to give me some assistance on the following situation.
>
> Our local Stately Home ("Kentwell Hall", Long Melford, Suffolk) is
> considering installing an Analemmatic sundial, as a new interactive
> attraction for visitors - but we are getting 'conflicting' advice,
> on whether this 'Human Sundial' will work in the way we want it to.
>
>
> We have been in discussion with "Modern Sunclocks" (apparently the
> acknowledged 'experts' for these features), who have told us that
> its central scale of dates must be aligned North/South - plus that
> hour markers must be correctly positioned on an elliptical ring,
> and which would lie on the Northern side of that scale of dates.
>
> Photographs on their website ( www.sunclocks.com ) confirm this.
>
>
> However, our 'Director of Operations' (Mr Phillips) absolutely
> INSISTS that he wants the scale to run exactly parallel with our
> main driveway - on a compass bearing which is about 162 degrees
> from North, with the hour points placed on its Southern side.
>
> He also wants the hour points to form an exact semi-circle, and
> not be elliptical in shape. Mr Phillips refuses to accept that
> he cannot arbitrarily position the Human Sundial feature as he
> wishes, and says that it must be possible to create this so that
> it could then align with the existing layout of buildings/paths.
>
>
> Can anyone on this Mailing List tell me whether it is possible to
> install a Human Sundial to fit any existing orientations, (with
> appropriate re-calculation of its component parts) - or, if not,
> just confirm that it must be as "Modern Sunclocks" have told me.
>
> I can then show the 'weight of evidence' to Mr Phillips. Because
> "Kentwell Hall" is a well-known Stately Home (open to the public),
> we should not want to become a 'laughing stock' by installing a
> feature which does not work - despite Mr Phillips assurance that
> "all types of sundial can be adjusted to work, in any location".
>
>
> Looking forward to all comments (to this List, or sent privately).
>
>
> Sincerely,
>
> Alison Shields.
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
RE: Advice wanted, on 'Analemmatic' sundial orientation
Dear Alison,
I think the experts have already told you what you need to know.
Of course, re-aligning the drive to run North-South would help a little.
This should be easier for Mr Phillips than re-aligning the Earth's axis.
Placing the whole estate on a turntable would be an alternative allowing
the present alignment of drive relative to house to be undisturbed. A
rough and ready allowance for Summer Time could then be made twice a
year which could become another tourist attraction if you can cope with
having Summer and Winter entrances. You may not want to transport it to
the Southern Hemisphere, though - nor to the pole when you can indeed
use a semicircle (or better still, a full circle).
Others may like to comment on the following thoughts:
If, instead of standing on the central "month" scale, the user finds and
stands on or near the hour number which casts his shadow onto the
appropriate date, the numbers might be arranged to the South rather than
to the North of the centre. This requires more action on the part of the
user.
A circular or other shape rather than a narrow rectangular centre
bearing the date scale might "disguise" the alignment a little.
If the hours were not in a horizontal plane, perhaps they could be
arranged to lie on a semicircle in some other plane - though not, I
think, what Mr Phillips would like?
(I was once involved in rectifying, as far as possible given what was
immovably fixed, an analemmatic dial at first incorrectly laid out, so I
do wish you well in this endeavour. It still ended up having timekeeping
errors but it was possible to spread them around so that none were too
enormous.)
Andrew James
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
On Behalf Of Alison Shields
Sent: 03 June 2008 18:57
To: sundial@uni-koeln.de
Subject: Advice wanted, on 'Analemmatic' sundial orientation
Dear Sundial Experts,
I have recently joined this Mailing List, and hope that any members
will be able to give me some assistance on the following situation.
Our local Stately Home ("Kentwell Hall", Long Melford, Suffolk) is
considering installing an Analemmatic sundial, as a new interactive
attraction for visitors - but we are getting 'conflicting' advice,
on whether this 'Human Sundial' will work in the way we want it to.
We have been in discussion with "Modern Sunclocks" (apparently the
acknowledged 'experts' for these features), who have told us that
its central scale of dates must be aligned North/South - plus that
hour markers must be correctly positioned on an elliptical ring,
and which would lie on the Northern side of that scale of dates.
Photographs on their website ( www.sunclocks.com ) confirm this.
However, our 'Director of Operations' (Mr Phillips) absolutely
INSISTS that he wants the scale to run exactly parallel with our
main driveway - on a compass bearing which is about 162 degrees
from North, with the hour points placed on its Southern side.
He also wants the hour points to form an exact semi-circle, and
not be elliptical in shape. Mr Phillips refuses to accept that
he cannot arbitrarily position the Human Sundial feature as he
wishes, and says that it must be possible to create this so that
it could then align with the existing layout of buildings/paths.
Can anyone on this Mailing List tell me whether it is possible to
install a Human Sundial to fit any existing orientations, (with
appropriate re-calculation of its component parts) - or, if not,
just confirm that it must be as "Modern Sunclocks" have told me.
I can then show the 'weight of evidence' to Mr Phillips. Because
"Kentwell Hall" is a well-known Stately Home (open to the public),
we should not want to become a 'laughing stock' by installing a
feature which does not work - despite Mr Phillips assurance that
"all types of sundial can be adjusted to work, in any location".
Looking forward to all comments (to this List, or sent privately).
Sincerely,
Alison Shields.
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
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RE: Advice wanted, on 'Analemmatic' sundial orientation
Alison,
You also can ask him to be dressed like the Wizard Merlin before starting the
self educational process described by Peter. This might help and make the
spectacle more amusing :-)
Best regards,
Ricardo
-- Início da mensagem original ---
De: [EMAIL PROTECTED]
Para: [EMAIL PROTECTED], sundial@uni-koeln.de
Cc:
Data: Wed, 4 Jun 2008 12:36:18 +0100
Assunto: RE: Advice wanted, on 'Analemmatic' sundial orientation
> Dear Alison,
>
> You have had a number of replies from experts greater than I, and they
> all say the same thing which I can't add to. I especially liked the one
> which suggested that Mr Phillips stand there and act as the gnomon
> (which is what you will be expecting the public to do). I suggest you
> challenge him on a sunny day (you haven't had many recently in Suffolk,
> but maybe this weekend coming...) with a compass in his hand, to try to
> twist and turn in any way to get his shadow to fall on the southern half
> of the dial. It should be an amusing spectacle, but should also be self
> instructive to him (if he doesn't believe the welter of opinion here).
> You can then ask how he expects the public to achieve what he failed to
> achieve.
>
> Regards
> Peter Tandy
>
> -Original Message-
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> On Behalf Of Alison Shields
> Sent: 03 June 2008 18:57
> To: sundial@uni-koeln.de
> Subject: Advice wanted, on 'Analemmatic' sundial orientation
>
>
> Dear Sundial Experts,
>
> I have recently joined this Mailing List, and hope that any members
> will be able to give me some assistance on the following situation.
>
> Our local Stately Home ("Kentwell Hall", Long Melford, Suffolk) is
> considering installing an Analemmatic sundial, as a new interactive
> attraction for visitors - but we are getting 'conflicting' advice,
> on whether this 'Human Sundial' will work in the way we want it to.
>
>
> We have been in discussion with "Modern Sunclocks" (apparently the
> acknowledged 'experts' for these features), who have told us that
> its central scale of dates must be aligned North/South - plus that
> hour markers must be correctly positioned on an elliptical ring,
> and which would lie on the Northern side of that scale of dates.
>
> Photographs on their website ( www.sunclocks.com ) confirm this.
>
>
> However, our 'Director of Operations' (Mr Phillips) absolutely
> INSISTS that he wants the scale to run exactly parallel with our
> main driveway - on a compass bearing which is about 162 degrees
> from North, with the hour points placed on its Southern side.
>
> He also wants the hour points to form an exact semi-circle, and
> not be elliptical in shape. Mr Phillips refuses to accept that
> he cannot arbitrarily position the Human Sundial feature as he
> wishes, and says that it must be possible to create this so that
> it could then align with the existing layout of buildings/paths.
>
>
> Can anyone on this Mailing List tell me whether it is possible to
> install a Human Sundial to fit any existing orientations, (with
> appropriate re-calculation of its component parts) - or, if not,
> just confirm that it must be as "Modern Sunclocks" have told me.
>
> I can then show the 'weight of evidence' to Mr Phillips. Because
> "Kentwell Hall" is a well-known Stately Home (open to the public),
> we should not want to become a 'laughing stock' by installing a
> feature which does not work - despite Mr Phillips assurance that
> "all types of sundial can be adjusted to work, in any location".
>
>
> Looking forward to all comments (to this List, or sent privately).
>
>
> Sincerely,
>
> Alison Shields.
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
RE: Advice wanted, on 'Analemmatic' sundial orientation
Dear Alison,
You have had a number of replies from experts greater than I, and they
all say the same thing which I can't add to. I especially liked the one
which suggested that Mr Phillips stand there and act as the gnomon
(which is what you will be expecting the public to do). I suggest you
challenge him on a sunny day (you haven't had many recently in Suffolk,
but maybe this weekend coming...) with a compass in his hand, to try to
twist and turn in any way to get his shadow to fall on the southern half
of the dial. It should be an amusing spectacle, but should also be self
instructive to him (if he doesn't believe the welter of opinion here).
You can then ask how he expects the public to achieve what he failed to
achieve.
Regards
Peter Tandy
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
On Behalf Of Alison Shields
Sent: 03 June 2008 18:57
To: sundial@uni-koeln.de
Subject: Advice wanted, on 'Analemmatic' sundial orientation
Dear Sundial Experts,
I have recently joined this Mailing List, and hope that any members
will be able to give me some assistance on the following situation.
Our local Stately Home ("Kentwell Hall", Long Melford, Suffolk) is
considering installing an Analemmatic sundial, as a new interactive
attraction for visitors - but we are getting 'conflicting' advice,
on whether this 'Human Sundial' will work in the way we want it to.
We have been in discussion with "Modern Sunclocks" (apparently the
acknowledged 'experts' for these features), who have told us that
its central scale of dates must be aligned North/South - plus that
hour markers must be correctly positioned on an elliptical ring,
and which would lie on the Northern side of that scale of dates.
Photographs on their website ( www.sunclocks.com ) confirm this.
However, our 'Director of Operations' (Mr Phillips) absolutely
INSISTS that he wants the scale to run exactly parallel with our
main driveway - on a compass bearing which is about 162 degrees
from North, with the hour points placed on its Southern side.
He also wants the hour points to form an exact semi-circle, and
not be elliptical in shape. Mr Phillips refuses to accept that
he cannot arbitrarily position the Human Sundial feature as he
wishes, and says that it must be possible to create this so that
it could then align with the existing layout of buildings/paths.
Can anyone on this Mailing List tell me whether it is possible to
install a Human Sundial to fit any existing orientations, (with
appropriate re-calculation of its component parts) - or, if not,
just confirm that it must be as "Modern Sunclocks" have told me.
I can then show the 'weight of evidence' to Mr Phillips. Because
"Kentwell Hall" is a well-known Stately Home (open to the public),
we should not want to become a 'laughing stock' by installing a
feature which does not work - despite Mr Phillips assurance that
"all types of sundial can be adjusted to work, in any location".
Looking forward to all comments (to this List, or sent privately).
Sincerely,
Alison Shields.
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Advice wanted, on 'Analemmatic' sundial orientation
Alison,
I think the only solution for Mr. Phillips is to create a new timesystem ;-)
Thibaud
At 19:57 03-06-2008, Alison Shields wrote:
Dear Sundial Experts,
I have recently joined this Mailing List, and hope that any members
will be able to give me some assistance on the following situation.
Our local Stately Home ("Kentwell Hall", Long Melford, Suffolk) is
considering installing an Analemmatic sundial, as a new interactive
attraction for visitors - but we are getting 'conflicting' advice,
on whether this 'Human Sundial' will work in the way we want it to.
We have been in discussion with "Modern Sunclocks" (apparently the
acknowledged 'experts' for these features), who have told us that
its central scale of dates must be aligned North/South - plus that
hour markers must be correctly positioned on an elliptical ring,
and which would lie on the Northern side of that scale of dates.
Photographs on their website ( www.sunclocks.com ) confirm this.
However, our 'Director of Operations' (Mr Phillips) absolutely
INSISTS that he wants the scale to run exactly parallel with our
main driveway - on a compass bearing which is about 162 degrees
from North, with the hour points placed on its Southern side.
He also wants the hour points to form an exact semi-circle, and
not be elliptical in shape. Mr Phillips refuses to accept that
he cannot arbitrarily position the Human Sundial feature as he
wishes, and says that it must be possible to create this so that
it could then align with the existing layout of buildings/paths.
Can anyone on this Mailing List tell me whether it is possible to
install a Human Sundial to fit any existing orientations, (with
appropriate re-calculation of its component parts) - or, if not,
just confirm that it must be as "Modern Sunclocks" have told me.
I can then show the 'weight of evidence' to Mr Phillips. Because
"Kentwell Hall" is a well-known Stately Home (open to the public),
we should not want to become a 'laughing stock' by installing a
feature which does not work - despite Mr Phillips assurance that
"all types of sundial can be adjusted to work, in any location".
Looking forward to all comments (to this List, or sent privately).
Sincerely,
Alison Shields.
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
--
Th. Taudin Chabot, . [EMAIL PROTECTED]
---
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Re: Advice wanted, on 'Analemmatic' sundial orientation
Hello Alison,
Tuesday, June 3, 2008, 8:57:15 PM, you wrote:
AS> Dear Sundial Experts,
AS> I have recently joined this Mailing List, and hope that any members
AS> will be able to give me some assistance on the following situation.
AS> Our local Stately Home ("Kentwell Hall", Long Melford, Suffolk) is
AS> considering installing an Analemmatic sundial, as a new interactive
AS> attraction for visitors - but we are getting 'conflicting' advice,
AS> on whether this 'Human Sundial' will work in the way we want it to.
AS> We have been in discussion with "Modern Sunclocks" (apparently the
AS> acknowledged 'experts' for these features), who have told us that
AS> its central scale of dates must be aligned North/South - plus that
AS> hour markers must be correctly positioned on an elliptical ring,
AS> and which would lie on the Northern side of that scale of dates.
AS> Photographs on their website ( www.sunclocks.com ) confirm this.
AS> However, our 'Director of Operations' (Mr Phillips) absolutely
AS> INSISTS that he wants the scale to run exactly parallel with our
AS> main driveway - on a compass bearing which is about 162 degrees
AS> from North, with the hour points placed on its Southern side.
AS> He also wants the hour points to form an exact semi-circle, and
AS> not be elliptical in shape. Mr Phillips refuses to accept that
AS> he cannot arbitrarily position the Human Sundial feature as he
AS> wishes, and says that it must be possible to create this so that
AS> it could then align with the existing layout of buildings/paths.
AS> Can anyone on this Mailing List tell me whether it is possible to
AS> install a Human Sundial to fit any existing orientations, (with
AS> appropriate re-calculation of its component parts) - or, if not,
AS> just confirm that it must be as "Modern Sunclocks" have told me.
AS> I can then show the 'weight of evidence' to Mr Phillips. Because
AS> "Kentwell Hall" is a well-known Stately Home (open to the public),
AS> we should not want to become a 'laughing stock' by installing a
AS> feature which does not work - despite Mr Phillips assurance that
AS> "all types of sundial can be adjusted to work, in any location".
AS> Looking forward to all comments (to this List, or sent privately).
AS> Sincerely,
AS> Alison Shields.
AS> ---
AS> https://lists.uni-koeln.de/mailman/listinfo/sundial
AS> __ NOD32 3154 (20080603) Information __
AS> This message was checked by NOD32 antivirus system.
AS> http://www.eset.com
Dear Alison,
If Mr. Phillips could act "the Sun", your Human Sundial
can "fit any existing orientations".
Best regards,
Todor Todorov ARBS
www.todor.org
mailto:[EMAIL PROTECTED]
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Advice wanted, on 'Analemmatic' sundial orientation
Mr. Philips can insist as much as he likes. However,
you might ask if he is related by ancestry to King
Canute. Same end result, won't and didn't work.
You might consider an analemma on the true north south
line, however, it only blurs the issue, not solves it.
All dials are presentation devices that present
projections of the sun, and thus its shadow. The
analemmatic dial is an azimuth dial with a gnomon base
point that moves with the date. The rules of physics
apply. The rules of geometry apply. Mr Philips wishes,
desires, and so on do not alter those basic rules.
Perhaps you might suggest that you can align the date
path for the dial with the house, by rotating the
house, that might be costly, but it would work.
There is a case study on my web site
www.illustratingshadows.com
which talks about constructing such a dial in a garden
area. Paragraph three states what by now must be
obvious:-
"The method is simple. A north south line is
constructed with a compass after considering
magnetic variation or declination."
Feel free to download it. And you can download similar
documents from other sources as well, all of which
support the above notes, and the answers that other
readers have returned to you.
Simon
www.illustratingshadows.com
--- Alison Shields <[EMAIL PROTECTED]>
wrote:
>
> Dear Sundial Experts,
>
> I have recently joined this Mailing List, and hope
> that any members
> will be able to give me some assistance on the
> following situation.
>
> Our local Stately Home ("Kentwell Hall", Long
> Melford, Suffolk) is
> considering installing an Analemmatic sundial, as a
> new interactive
> attraction for visitors - but we are getting
> 'conflicting' advice,
> on whether this 'Human Sundial' will work in the way
> we want it to.
>
>
> We have been in discussion with "Modern Sunclocks"
> (apparently the
> acknowledged 'experts' for these features), who have
> told us that
> its central scale of dates must be aligned
> North/South - plus that
> hour markers must be correctly positioned on an
> elliptical ring,
> and which would lie on the Northern side of that
> scale of dates.
>
> Photographs on their website ( www.sunclocks.com )
> confirm this.
>
>
> However, our 'Director of Operations' (Mr Phillips)
> absolutely
> INSISTS that he wants the scale to run exactly
> parallel with our
> main driveway - on a compass bearing which is about
> 162 degrees
> from North, with the hour points placed on its
> Southern side.
>
> He also wants the hour points to form an exact
> semi-circle, and
> not be elliptical in shape. Mr Phillips refuses to
> accept that
> he cannot arbitrarily position the Human Sundial
> feature as he
> wishes, and says that it must be possible to create
> this so that
> it could then align with the existing layout of
> buildings/paths.
>
>
> Can anyone on this Mailing List tell me whether it
> is possible to
> install a Human Sundial to fit any existing
> orientations, (with
> appropriate re-calculation of its component parts) -
> or, if not,
> just confirm that it must be as "Modern Sunclocks"
> have told me.
>
> I can then show the 'weight of evidence' to Mr
> Phillips. Because
> "Kentwell Hall" is a well-known Stately Home (open
> to the public),
> we should not want to become a 'laughing stock' by
> installing a
> feature which does not work - despite Mr Phillips
> assurance that
> "all types of sundial can be adjusted to work, in
> any location".
>
>
> Looking forward to all comments (to this List, or
> sent privately).
>
>
> Sincerely,
>
> Alison Shields.
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Advice wanted, on 'Analemmatic' sundial orientation
Hi Alison, Executive summary: Mr. Phillips can't have it. More detail: the central scale of dates is a projection of the direction of the Earth's axis. This fixes the direction of the date scale on a horizontal dial to point along North-South. Nothing can be done about it (other than tilting the planet differently :-) Also, he can have a circular (non-elliptical) dial only if: - either the gnomon is non-vertical; since the gnomon must be vertical (a person standing up), this is also out of question, - or the dial plane is not horizontal. This may be more reasonable, depending on the physical layout of the area. -- Jan Bielawski --- https://lists.uni-koeln.de/mailman/listinfo/sundial
RE: Advice wanted, on 'Analemmatic' sundial orientation
Since it's not April First, I can only conclude that this an outstanding
example of understated British humor, worthy of P.G. Wodehouse.
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
On Behalf Of Alison Shields
Sent: Tuesday, June 03, 2008 1:57 PM
To: sundial@uni-koeln.de
Subject: Advice wanted, on 'Analemmatic' sundial orientation
Dear Sundial Experts,
I have recently joined this Mailing List, and hope that any members will
be able to give me some assistance on the following situation.
Our local Stately Home ("Kentwell Hall", Long Melford, Suffolk) is
considering installing an Analemmatic sundial, as a new interactive
attraction for visitors - but we are getting 'conflicting' advice, on
whether this 'Human Sundial' will work in the way we want it to.
We have been in discussion with "Modern Sunclocks" (apparently the
acknowledged 'experts' for these features), who have told us that its
central scale of dates must be aligned North/South - plus that hour
markers must be correctly positioned on an elliptical ring, and which
would lie on the Northern side of that scale of dates.
Photographs on their website ( www.sunclocks.com ) confirm this.
However, our 'Director of Operations' (Mr Phillips) absolutely INSISTS
that he wants the scale to run exactly parallel with our main driveway -
on a compass bearing which is about 162 degrees from North, with the
hour points placed on its Southern side.
He also wants the hour points to form an exact semi-circle, and not be
elliptical in shape. Mr Phillips refuses to accept that he cannot
arbitrarily position the Human Sundial feature as he wishes, and says
that it must be possible to create this so that it could then align with
the existing layout of buildings/paths.
Can anyone on this Mailing List tell me whether it is possible to
install a Human Sundial to fit any existing orientations, (with
appropriate re-calculation of its component parts) - or, if not, just
confirm that it must be as "Modern Sunclocks" have told me.
I can then show the 'weight of evidence' to Mr Phillips. Because
"Kentwell Hall" is a well-known Stately Home (open to the public), we
should not want to become a 'laughing stock' by installing a feature
which does not work - despite Mr Phillips assurance that "all types of
sundial can be adjusted to work, in any location".
Looking forward to all comments (to this List, or sent privately).
Sincerely,
Alison Shields.
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Advice wanted, on 'Analemmatic' sundial orientation
Good luck, Alison!
I'll let the real experts address the weight of evidence, but you are
quite correct, and Mr. Phillips is wrong. While many types of sundials can
indeed be "adjusted" to operate in any location, they cannot be adjusted
to arbitrary orientation.
For the simplest argument you might present to him, point out that the
human gnomon casts a shadow to the North (at say, local noon). It would be
impossible to place the hour lines/points to the South and have them
function! (He isn't from Australia, by any chance?)
Dave
>
> Dear Sundial Experts,
>
> I have recently joined this Mailing List, and hope that any members
> will be able to give me some assistance on the following situation.
>
> Our local Stately Home ("Kentwell Hall", Long Melford, Suffolk) is
> considering installing an Analemmatic sundial, as a new interactive
> attraction for visitors - but we are getting 'conflicting' advice,
> on whether this 'Human Sundial' will work in the way we want it to.
>
>
> We have been in discussion with "Modern Sunclocks" (apparently the
> acknowledged 'experts' for these features), who have told us that
> its central scale of dates must be aligned North/South - plus that
> hour markers must be correctly positioned on an elliptical ring,
> and which would lie on the Northern side of that scale of dates.
>
> Photographs on their website ( www.sunclocks.com ) confirm this.
>
>
> However, our 'Director of Operations' (Mr Phillips) absolutely
> INSISTS that he wants the scale to run exactly parallel with our
> main driveway - on a compass bearing which is about 162 degrees
> from North, with the hour points placed on its Southern side.
>
> He also wants the hour points to form an exact semi-circle, and
> not be elliptical in shape. Mr Phillips refuses to accept that
> he cannot arbitrarily position the Human Sundial feature as he
> wishes, and says that it must be possible to create this so that
> it could then align with the existing layout of buildings/paths.
>
>
> Can anyone on this Mailing List tell me whether it is possible to
> install a Human Sundial to fit any existing orientations, (with
> appropriate re-calculation of its component parts) - or, if not,
> just confirm that it must be as "Modern Sunclocks" have told me.
>
> I can then show the 'weight of evidence' to Mr Phillips. Because
> "Kentwell Hall" is a well-known Stately Home (open to the public),
> we should not want to become a 'laughing stock' by installing a
> feature which does not work - despite Mr Phillips assurance that
> "all types of sundial can be adjusted to work, in any location".
>
>
> Looking forward to all comments (to this List, or sent privately).
>
>
> Sincerely,
>
> Alison Shields.
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
Advice wanted, on 'Analemmatic' sundial orientation
Dear Sundial Experts,
I have recently joined this Mailing List, and hope that any members
will be able to give me some assistance on the following situation.
Our local Stately Home ("Kentwell Hall", Long Melford, Suffolk) is
considering installing an Analemmatic sundial, as a new interactive
attraction for visitors - but we are getting 'conflicting' advice,
on whether this 'Human Sundial' will work in the way we want it to.
We have been in discussion with "Modern Sunclocks" (apparently the
acknowledged 'experts' for these features), who have told us that
its central scale of dates must be aligned North/South - plus that
hour markers must be correctly positioned on an elliptical ring,
and which would lie on the Northern side of that scale of dates.
Photographs on their website ( www.sunclocks.com ) confirm this.
However, our 'Director of Operations' (Mr Phillips) absolutely
INSISTS that he wants the scale to run exactly parallel with our
main driveway - on a compass bearing which is about 162 degrees
from North, with the hour points placed on its Southern side.
He also wants the hour points to form an exact semi-circle, and
not be elliptical in shape. Mr Phillips refuses to accept that
he cannot arbitrarily position the Human Sundial feature as he
wishes, and says that it must be possible to create this so that
it could then align with the existing layout of buildings/paths.
Can anyone on this Mailing List tell me whether it is possible to
install a Human Sundial to fit any existing orientations, (with
appropriate re-calculation of its component parts) - or, if not,
just confirm that it must be as "Modern Sunclocks" have told me.
I can then show the 'weight of evidence' to Mr Phillips. Because
"Kentwell Hall" is a well-known Stately Home (open to the public),
we should not want to become a 'laughing stock' by installing a
feature which does not work - despite Mr Phillips assurance that
"all types of sundial can be adjusted to work, in any location".
Looking forward to all comments (to this List, or sent privately).
Sincerely,
Alison Shields.
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
