Re: One piece card construction universal ring sundial prototype
That's a great experiment in dialing and very useful to understand gnomonics. Of course this dial will work well in other latitudes if set to the latitude. Thanks for sharing your model. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "wee-meng lee" <[EMAIL PROTECTED]> To: "'Sundial List'" Sent: Friday, June 03, 2005 4:49 AM Subject: One piece card construction universal ring sundial prototype Hi, Thanks to the help I got here, I finally got the card universal ring dial completed last night. http://leewm.freeshell.org/origami/ringdial.pdf I haven't put it in the main index yet because I don't know if it is really "universal". I only tested it in the month of May and June. Furthermore, I don't know if I got the date inscriptions on the gnomon in the right orientation but the contraption seem to work in Singapore for June. When the spot of light shone on the hour ring, it pointed North and tallied with the local time. What I'm curious now is whether it will it work in the other latitudes. If you happen to try it out, can u pls let me know? Thank you, weemeng - -
Re: How to calculate "gnomon" of ring sundial?
Sundials are interesting indeed, but some study is necessary. On the WEB many sites will help you. The ring dial you noted is in fact an equatorial sundial. In use its inner ring lies in the equatorial plane. The inner diameter of that ring is R. The point on the date scale is from the centre: y = R tan decl. Decl is the declination of the sun, relative to the date. It is the angle the sun is north or south the equator. That's all. Best wishes, Fer. Fer J. de Vries Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "wee-meng lee" <[EMAIL PROTECTED]> To: "Sundial" Sent: Tuesday, May 24, 2005 7:34 AM Subject: How to calculate "gnomon" of ring sundial? Hello, I've always been fascinated by Sun dials and have just found this group surfing around after making my first working Sundial using Shadowspro. It's found here: http://leewm.freeshell.org/origami. All the sundials that I've made before didn't work in my location as I didn't understand the concepts and they were designed for the more northern regions. In the ring sundial found in http://www.pocketsundial.com/, how does one calculate the the location of the hole in the centre portion that acts as the gnomon? I'm sure the radius of the circle has something to do with it. I'm sorry if I used the wrong terms as I'm just picking up the vocabulary. Thx very much :) weemeng - -
Re: M. C. Escher sundial drawing
Friends, De translation of the Escher poem was done by Ruud Hooiienga, member of the board of De Zonnewijzerkring. Ruud also translates the Dutch pages of our web site into English. You may recognize that by the note on each translated page: English translation: RH. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: Robert Terwilliger To: 'Sundial Mailing List' Sent: Friday, April 29, 2005 10:49 PM Subject: M. C. Escher sundial drawing I came across a drawing of a sundial by M. C. Escher. It's rather tame compared to his better-known illustrations. It includes an epigram in Dutch which has been nicely translated by Fer deVries and a colleague - as a poem. The illustration also includes text in Latin(?): PATET QUAELIBET ULTIMA LATET. Can any of our Latin scholars help? Look under New Links: http://sundials.org/links/ ... while you're there take a look at "The sundial" at Wentworth castle. I've never seen one quite like this. Bob
Re: Reykjavik shadow plane dial
Hi Mac, S/he/it looks very friendly to me. If s/he/it stood there all winter with no harm by the Brattleboro people walking by the latter must be friendly also. That's a good feeling for Aliens and for Earth Inhabitants and hopefully for the future. If I stood for such a long time I needed a wee-wee so s/he/it certainly will be a he I think. It's hard to give a good definition for a shadow or hour plane dial. Also a normal polestyle dial is a shadow plane dial, isn't it? In which intermediate times easily may be read. I only should give a discription with one or two examples. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Mac Oglesby" <[EMAIL PROTECTED]> To: "Fer J. de Vries" <[EMAIL PROTECTED]> Sent: Monday, April 25, 2005 7:52 PM Subject: Re: Reykjavik shadow plane dial > > Hi Fer, > > It certainly is a multiple dial, and I think you're right that is > probably isn't really a shadow plane. I guess I got carried away as I > watched the shadows play across the vanes. > > Come to think about it, I don't believe I've seen a really good > definition of shadow plane sundials. The one in John Davis' Glossary > (2nd edition) is not adequate, as it only deals with some types of > shadow plane dials. I think there are shadow plane dials which don't > have a moveable gnomon, such as shadow plane dials with tilted slabs > or those with several cable gnomons. > > Have you ever written (or even seen) a comprehensive definition for > shadow plane sundials? What would you reply to someone who asked you > "What is a shadow plane sundial?" > > Best wishes, > > Mac > > P.S. I had intended the following for an April Fool's Day joke on > April 1st, but didn't snap the photo in time. > > Dressed in a metallic cloak, an alien shape spent the winter perched > next to the sidewalk on Western Avenue in Brattleboro. As the tiny > inserted side view shows, with the coming of warmer temperatures > s/he/it has extended a proboscis into the nearby grass, perhaps for > feeding purposes, perhaps for breeding...??? > > > > > > > > > > > > > >Hi Mac, > > > >Is it a shadowplane dial or a multiple dial? > >Each dial face works for an hour and after that a second one is used an so > >on. > >Just a small remark for a nice concept. > > > >Best wishes, Fer. > > > >Fer J. de Vries > > > >De Zonnewijzerkring > >mailto:[EMAIL PROTECTED] > >http://www.de-zonnewijzerkring.nl > > > >Home > >mailto:[EMAIL PROTECTED] > >http://www.iae.nl/users/ferdv/index-fer.htm > >Eindhoven, Netherlands > >lat. 51:30 N long. 5:30 E > > > >- Original Message - > >From: "Mac Oglesby" <[EMAIL PROTECTED]> > >To: > >Sent: Monday, April 25, 2005 11:10 AM > >Subject: Reykjavik shadow plane dial > > > > > >> > >> Hello Friends... > >> > >> The NASS website has posted a link to Dale M. Greer's fascinating > >> model of a monumental shadow plane dial for Reykjavik. > >> > >> http://sundials.org > >> click on Links > >> click on New Links > >> click on Sundial for Reykjavik > >> > >> If you click on the images, you can see movies of the sundial in action. > >> > >> If you click on Sundials at the page bottom, you can read a little > >> more about Greer's sundials, dating back to 1994, before most of us > >> had ever heard of shadow plane sundials. > >> > >> Thanks to Bob Terwilliger for posting this. > >> > >> Best wishes, > >> > >> Mac > >> - >
Re: Reykjavik shadow plane dial
Hi Mac, Is it a shadowplane dial or a multiple dial? Each dial face works for an hour and after that a second one is used an so on. Just a small remark for a nice concept. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Mac Oglesby" <[EMAIL PROTECTED]> To: Sent: Monday, April 25, 2005 11:10 AM Subject: Reykjavik shadow plane dial > > Hello Friends... > > The NASS website has posted a link to Dale M. Greer's fascinating > model of a monumental shadow plane dial for Reykjavik. > > http://sundials.org >click on Links >click on New Links >click on Sundial for Reykjavik > > If you click on the images, you can see movies of the sundial in action. > > If you click on Sundials at the page bottom, you can read a little > more about Greer's sundials, dating back to 1994, before most of us > had ever heard of shadow plane sundials. > > Thanks to Bob Terwilliger for posting this. > > Best wishes, > > Mac > -
Re: Brad Lufkin's PC sundial programs
Hi Mac, That's good news that you are able to connect to our web site. Now you may see where a lot of my time is going to. Hope Brad can be of help. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Mac Oglesby" <[EMAIL PROTECTED]> To: "Fer J. de Vries" <[EMAIL PROTECTED]> Sent: Wednesday, April 20, 2005 8:53 PM Subject: Re: Brad Lufkin's PC sundial programs > > Hi Fer, > > Thanks for your message. I just tried, on my PC, the Windows material > Brad sent and got the message "The application or DLL > C:\WINDOWS\systemxnmba420.dll is not a valid Windows image." > > I'll contact Brad and see if he has any suggestions. > > Best wishes, > > Mac > > P.S. Good news! I have just discovered that I can now connect with > http://www.de-zonnewijzerkring.nl/. I have no idea why it works now, > but didn't for so long. > > > > > > > > > >Hi Mac, > > > >A good idea to place the PC program by Brad Lufkin for download on your > >address. > >So I downloaded the file and tried the program. > > > >But I got a message that a file xnmba420.dll is missing. > > > >Do you have that file or could Brad be of help and could you send me that > >file if you have it? > >I am curious what program Brad made. > > > > > >Best wishes, Fer. > > > >Fer J. de Vries > > > >De Zonnewijzerkring > >mailto:[EMAIL PROTECTED] > >http://www.de-zonnewijzerkring.nl > > > >Home > >mailto:[EMAIL PROTECTED] > >http://www.iae.nl/users/ferdv/index-fer.htm > >Eindhoven, Netherlands > >lat. 51:30 N long. 5:30 E > > > >- Original Message - > >From: "Mac Oglesby" <[EMAIL PROTECTED]> > >To: "Sundial List" > >Sent: Tuesday, April 19, 2005 11:24 PM > >Subject: Brad Lufkin's PC sundial programs > > > > > >> > >> A zip file containing the PC versions of Brad Lufkin's sundial > >> programs has been posted for download at: > >> > >> http://www.sover.net/~oglesby/LufkinSundialsPC/ > >> > >> Questions, suggestions, thanks, etc. concerning these programs should > >> be directed to Brad Lufkin <[EMAIL PROTECTED]> > >> > >> Best wishes, > >> > >> Mac > >> - >
Re: Brad Lufkin's PC sundial programs
Hi Mac, A good idea to place the PC program by Brad Lufkin for download on your address. So I downloaded the file and tried the program. But I got a message that a file xnmba420.dll is missing. Do you have that file or could Brad be of help and could you send me that file if you have it? I am curious what program Brad made. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Mac Oglesby" <[EMAIL PROTECTED]> To: "Sundial List" Sent: Tuesday, April 19, 2005 11:24 PM Subject: Brad Lufkin's PC sundial programs > > A zip file containing the PC versions of Brad Lufkin's sundial > programs has been posted for download at: > > http://www.sover.net/~oglesby/LufkinSundialsPC/ > > Questions, suggestions, thanks, etc. concerning these programs should > be directed to Brad Lufkin <[EMAIL PROTECTED]> > > Best wishes, > > Mac > -
Re: azimuth diagram
Hi Mac, I once wrote a program Foster, not completed to the end but a sun compass is included. The output file may be used as input for ZW2000. I think I sent it to you. If not, ask me and I will do so. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Mac Oglesby" <[EMAIL PROTECTED]> To: "Fer J. de Vries" <[EMAIL PROTECTED]> Sent: Friday, February 04, 2005 5:29 PM Subject: Re: azimuth diagram > > Hi Fer, > > I think I remember that one of your programs draws a sun compass, but > can't remember which one. Help? > > Best wishes, > > Mac > > > > > > > > > >Hi Frank, > > > >You are constructing a sun compass with the Weir diagram, based on the > >analemmatic sundial. > >A lot has been written about. > > > >Have a look in Compendium, september 2003 for the article > >>From Universal Analemmatic To Sun Compass - Filling The Gaps > >by Frederick W. Sawyer > > > > > >Best wishes, Fer. > > > >Fer J. de Vries > > > >De Zonnewijzerkring > >mailto:[EMAIL PROTECTED] > >http://www.de-zonnewijzerkring.nl > > > >Home > >mailto:[EMAIL PROTECTED] > >http://www.iae.nl/users/ferdv/index-fer.htm > >Eindhoven, Netherlands > >lat. 51:30 N long. 5:30 E > > > >- Original Message - > >From: "Frank Evans" <[EMAIL PROTECTED]> > >To: "Sundial" > >Sent: Thursday, February 03, 2005 10:18 PM > >Subject: azimuth diagram > > > > > >> Greetings fellow dialists, > >> > >> The other day I bought a copy of Weir's Azimuth Diagram. This was the > >first > >> time I had seen it although I had read about it in earlier days. It is a > >> remarkable document, devised by Captain Weir in 1890. Its purpose is to > >> enable a navigator to find the azimuth of a heavenly body by graphical > >> means. > >> > >> In appearance it is a circle of 50 cm diameter on paper, containing a > >> central vertical ordinate, a series of concentric ellipses and mirrored > >> hyperbolic curves spreading from the central ordinate. It makes a very > >> pretty picture and is in colour. The diagram is entered with the elements > >> latitude (expressed as an ellipse), declination of the heavenly body > >> (expressed linearly on the vertical ordinate) and the hour angle (crudely, > >> sun time) of the heavenly body (expressed as a hyperbolic curve). Marking > >> the declination on the vertical ordinate (which is pricked out in degrees > >> from 65N to 65S) and joining this point to a second point where the > >> appropriate latitude ellipse crosses the hour angle hyperbola gives a line > >> which plots the azimuth of the heavenly body in question. > >> > >> It occurred to me that this graphical method of solving azimuth problems > >> could be modified to make a sundial. If the Weir diagram were to be > >levelled > >> and oriented N and S and a vertical shadow pin were placed on the central > >> ordinate at the sun's declination then the shadow would represent its > >> azimuth. Follow this until it reaches the appropriate latitude curve and > >> read off the time from the conjoined hour angle curve. > >> > >> Two points (1) This diagram is a fascinating survival, last printed in > >1950 > >> and still obtainable from UK Admiralty chart agents. It is catalogued as > >> chart no. 5000 and is printed on good quality chart paper. It costs 5 > >pounds > >> 50. There is a second diagram available for the hardy ones, extending from > >> 65 deg to 80 deg. > >> > >> (2) Have I got all this right? Is anyone else familiar with Weir's diagram > >> and has it been mentioned before in this sundial group? > >> > >> Frank 55N 1W > >> > >> - > > > >- >
Re: azimuth diagram
Hi Frank, You are constructing a sun compass with the Weir diagram, based on the analemmatic sundial. A lot has been written about. Have a look in Compendium, september 2003 for the article >From Universal Analemmatic To Sun Compass - Filling The Gaps by Frederick W. Sawyer Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Frank Evans" <[EMAIL PROTECTED]> To: "Sundial" Sent: Thursday, February 03, 2005 10:18 PM Subject: azimuth diagram > Greetings fellow dialists, > > The other day I bought a copy of Weir's Azimuth Diagram. This was the first > time I had seen it although I had read about it in earlier days. It is a > remarkable document, devised by Captain Weir in 1890. Its purpose is to > enable a navigator to find the azimuth of a heavenly body by graphical > means. > > In appearance it is a circle of 50 cm diameter on paper, containing a > central vertical ordinate, a series of concentric ellipses and mirrored > hyperbolic curves spreading from the central ordinate. It makes a very > pretty picture and is in colour. The diagram is entered with the elements > latitude (expressed as an ellipse), declination of the heavenly body > (expressed linearly on the vertical ordinate) and the hour angle (crudely, > sun time) of the heavenly body (expressed as a hyperbolic curve). Marking > the declination on the vertical ordinate (which is pricked out in degrees > from 65N to 65S) and joining this point to a second point where the > appropriate latitude ellipse crosses the hour angle hyperbola gives a line > which plots the azimuth of the heavenly body in question. > > It occurred to me that this graphical method of solving azimuth problems > could be modified to make a sundial. If the Weir diagram were to be levelled > and oriented N and S and a vertical shadow pin were placed on the central > ordinate at the sun's declination then the shadow would represent its > azimuth. Follow this until it reaches the appropriate latitude curve and > read off the time from the conjoined hour angle curve. > > Two points (1) This diagram is a fascinating survival, last printed in 1950 > and still obtainable from UK Admiralty chart agents. It is catalogued as > chart no. 5000 and is printed on good quality chart paper. It costs 5 pounds > 50. There is a second diagram available for the hardy ones, extending from > 65 deg to 80 deg. > > (2) Have I got all this right? Is anyone else familiar with Weir's diagram > and has it been mentioned before in this sundial group? > > Frank 55N 1W > > - -
Re: Earliest Sundials
Dear Mike, On the Sundial list something has been written about the oldest polestyle dial. I made a note of what was written and that note is copied below. Lateron I have read about such a dial from 1372 by Ibn al Shatir. That is added in the same note. Best wishes, Fer. - Krzysztof Kotynia wrote: > > > > Piero Ranfagni wrote: > > > Dear friends, > > > I need your help: I'm preparaing a lesson around the mesaurement of > > > time. I wolud like to know how old is the first equal hours sundial.Rohr > > > claimed that the "Man with the sundial" in the Cathedral of Strasbourg > > > is the earliest modern sundial and it dates from 1493. What is your > > > opinion? Can you indicate me some books on the subject? > > > > > I don't know what dial with equal hours is the oldest , but on the site of De Zonnewijzerkring > > you may see a sundial in Utrecht, Netherlands, dated 1463. > > It is a small dial, still existing and dated. > > > > Fer J. de Vries > > [EMAIL PROTECTED] > > > Dear Piero, > in other countries there are also sundials of equal hours > dated earlier than Rohr's example. > In the Museum of Jagiellonian University (Krakow, Poland) > is beautifully preserved > sundial designed by Marcin (Martin) Bylica, the professor of > astronomy in that University and carried out in 1485 by Hans Dorn > in Vienna in 1485. That sundial and other astronomical instruments > (a celestial globe, a very big astrolabe and so called torquetum) > Marcin Bylica bequeathed to the University. > So I think that sundials with equal hours a earlier that Rohr > thinks. > Best regards > Krzysztof Kotynia > lat 51.8N long.19.4E According to Ernst Zinner: "Astronomische Instrumente des 1.. bis 18. Jahrhunderts " (Astronomic instruments of the 11. until 18. Century ), publishing house C. H. Beck, 1979 the Astronomer and Mathematician Georg Peuerbach, (1423 - 1461) from Vienna created the first sharped table sundial of the world in the year 1451. It is in the museum Zeughaus Kaiser Maximilian I. in Innsbruck. You will find a picture and further explanations to this sundial in my homepage. http://www.tirol.com/sundial/ It is the sundial No. 2 in my collection. Karl Schwarzinger 47°14,3' N 11°26,7' E E-Mail : [EMAIL PROTECTED] An older one on a wall is Duderstadt, Germany, 1456 ( zie oom catalogus Duitsland, 37115 Duderstadt ) also old is Kaschau, Slowakia, 1477 ( Koice b Pronunciation: [kô´shitse] Ger. Kaschau, Hung. Kassa, city (1990 est. pop. 237,100), E Slovakia. ) A list you find in Zinner: Alte Sonnenuhren an europäischen Gebäuden, page 13 Happy dialling Klaus Eichholz [EMAIL PROTECTED] We have now: Strassbourg, France 1493 Building Cathedral Krakow, Poland 1485 Museum Kaschau, Slowakia, 1477 ?? Utrecht, Netherlands 1463 Building Church Duderstadt 1456 Building Cathedral Innsbruck, Austria 1451 Museum Wien, Austria 1451 Stephansdom Cathedral But where is the oldest? Who knows of older ones? Damascus 1372 Horizontal sundial by Ibn al Shatir Now replica but old parts seem to be present. Read: - Astronomy before the telescope page. 169 - Rohr, Die Sonnenuhr, page 174 - Osmanli Günes Saatleri, page. 30 en 174 - Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkringnl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: Mike Cowham To: SUNDIAL Sent: Friday, December 24, 2004 4:38 PM Subject: Earliest Sundials Dear Sundial Friends, I am trying to find the earliest evidence for sundials made in Europe with gnomons aligned to the Earth's axis. They were commonly in use after about 1550, (e.g., Nuremberg diptych dials), but I believe that there are much earlier ones. Rohr, in his book, believes that the technology probably came to Europe from the Arabs following the crusades, the last of which finished around 1290. One string gnomon dial is illustrated by Zinner that he believes was made by Regiomontanus in 1463. Does anyone know of any earlier dials, fixed or portable using this 'new technology', or any dials with the new gnomon earlier than 1550? Best Wishes to all my Sundial Friends for Christmas and the New Year. Regards,Mike CowhamCambridge UK
Re: Fw: 'Wineglass' of Sonius
Hi Peter, In both planes the width of the slots is changing. For each half hour we tried to get the line of light disappearnig from an hour line and at the same moment a new line appearing on the next hour line. We did some experiments but the final was determined with the help of construction in Autocad. Don't ask me how I did it so many years ago. The gentleman with the beard is a self portrait of Bill as he demonstrates the principle of hour or shadow planes very clear. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Peter Mayer" <[EMAIL PROTECTED]> To: "Fer J. de Vries" <[EMAIL PROTECTED]>; Sent: Sunday, November 21, 2004 11:57 PM Subject: Re: Fw: 'Wineglass' of Sonius > Hi Fer, > Thank you very much for your comments. I should have checked the > URL for Karl's page; I see now that I consulted it a bit over a year ago. > I have two questions, one sensible (I hope), the other quite > childish, which I hope you will forgive! >You noted "Because of the thickness of the two plates the slots > needed to be of different widths. This was the most difficult part of > the calculation". Here, I imagine, that the slots on the 'sun side' had > to be wider than those on the 'dial side'. Is the best width of the > slots something one determines by experiment, depending on the size of > the dial and the thickness of the blocks? > Secondly, your reference to the articles in the Compendium reminded > me of something quite silly. In Figure 7 of the first article there is > a drawing of a handsome gentleman with a beard looking at the shadow of > a string. As one does when one tries to imagine the face of a person > whose voice one hears on the radio, I have wondered, more than once, > whether there is any resemblance to Fer,or Mac or Bill...! > > warmest wishes, > > Peter > > > > -- > Peter Mayer > Politics Department > Adelaide University, AUSTRALIA 5005 > Ph: +61 8 8303 5606 > Fax : +61 8 8303 3446 > e-mail: [EMAIL PROTECTED] > > --- > This email message is intended only for the addressee(s) > and contains information which may be confidential and/or > copyright. If you are not the intended recipient please > do not read, save, forward, disclose, or copy the contents > of this email. If this email has been sent to you in error, > please notify the sender by reply email and delete this > email and any copies or links to this email completely and > immediately from your system. No representation is made > that this email is free of viruses. Virus scanning is > recommended and is the responsibility of the recipient. > > -
Fw: 'Wineglass' of Sonius
> Peter, > > The link to the site of Karl Schwarzinger didn't work but this one does. > http://members.aon.at/sundials/index.html > Look for picture 40 (Bild 40) > > The tree of Sonius is made of two separate plates and calculated as you > suggested. > A dial on the north plate and a dial on the south plate with the dial > centers on the same (imaginair) polestyle. > > The slots in the plates were not cut in the direction of the hourplanes. > It was considered but it was to complecated in this case. > Because of the thickness of the two pates the slots needed to be of > different width. > That was the most difficult part of the calculations. > > In an massive block an aesier method for the calculation is to calculate how > the hourplane is oriented for each hourline in respect to the plane of the > dial or to the horizontal plane. > It's the hourline and an angle to the hourplane. > This is enough to rotate the block in the right position to cut the slots in > the block. > > Read in Compendium vol. 6 nr. 3 and 4, 1999, the aticles about Shadow Plane > Sundials. > > On Internet look at the site of De Zonnewijzerkring ( address below) and > follw the links: > - Links > - Members > - Fer de Vries > Somewhere down you find links to the same articles in Compendium. > > Best wishes, Fer. > > > Fer J. de Vries > > De Zonnewijzerkring > mailto:[EMAIL PROTECTED] > http://www.de-zonnewijzerkring.nl > > Home > mailto:[EMAIL PROTECTED] > http://www.iae.nl/users/ferdv/index-fer.htm > Eindhoven, Netherlands > lat. 51:30 N long. 5:30 E > > - Original Message - > From: "Peter Mayer" <[EMAIL PROTECTED]> > To: > Sent: Friday, November 19, 2004 4:32 AM > Subject: 'Wineglass' of Sonius > > > > Hi, > > > > I've been thinking for some time about making dial on the model of > > the "Tree of Sonius" in Limburg, Belgium (see Karl Schwarzinger's great > > homepage: http://members.tirol.com/k.schwarzinger/b_5650.htm for a > > picture of the dial and a very clear diagram illustrating the principle > > of the dial. Thanks Karl!). Since my model will be for the southern > > hemisphere, but is to be read 'left to right' it will have to be > > 'bowl-shaped' (or as I prefer to think of it, 'wineglass-shaped'!) > > rather than 'umbrella-shaped' as is the Limburg original. > > My question to the group is: what is the simplest, most sensible way > > with a modest kit of hand/power tools to cut the complex shadow plane > > slots for each hour? > > My present thinking suggests i) drawing a normal vertical dial for > > my location on the north face, then ii)'extending' the angle of the > > style (from the 6 o'clock line) across the side of the block which > > constitutes the dial and using the intersection of the style extension > > with the south side of the block to position and draw a second vertical > > dial--a mirror image, of course. Step iii) is to connect the respective > > hour lines on the two faces across the edges. Step iv) would be to > > successively align the block so that each hour plane is vertical and use > > a mitre box to cut the shadow plane slots. > > Since Fer de Vries co-designed the original, I'm sure he'll have a > > far more sensible plan! (How on earth was it done in stainless steel??) > > > > Many thanks, > > > > Peter Mayer > > > > -- > > Peter Mayer > > Politics Department > > Adelaide University, AUSTRALIA 5005 > > Ph: +61 8 8303 5606 > > Fax : +61 8 8303 3446 > > e-mail: [EMAIL PROTECTED] > > > > --- > > This email message is intended only for the addressee(s) > > and contains information which may be confidential and/or > > copyright. If you are not the intended recipient please > > do not read, save, forward, disclose, or copy the contents > > of this email. If this email has been sent to you in error, > > please notify the sender by reply email and delete this > > email and any copies or links to this email completely and > > immediately from your system. No representation is made > > that this email is free of viruses. Virus scanning is > > recommended and is the responsibility of the recipient. > > > > > > - > -
Re: R:R:
Hi Gianni, Thanks for your opinion about the question by Lucio Baruffi. It supports the point of view I have about the older gnomonics. It may be done otherwise as Lucio wrote but that wasn't common. I refer to your book Relazione e formule per lo studio delle meridiane piane, 1998, page 16, where you describe the hourlines with respect to Crepuscolo Civile, Nautico and Astronomico. There is to see that the hourlines in these cases also will become curved lines but this certainly isn't what we see on older sundials. So my opinion still is that there is a difference in how gnonomics was from historical point of view and what we may do nowadays. I also realised that the analemma of Vitruvius could be seen as an replacement of the formula for half the dayength but I didn't write it down.. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: Gianni Ferrari To: LISTA INGLESE Sent: Thursday, September 30, 2004 6:04 PM Subject: R:R: Dear Baruffi, obviously, as also you say, each of us can calculate his own sundials with the method and the formulas that more he prefers and loves. It is therefore possible to consider the instant of the sunset as defined by modern astronomers and to use both the upper bound of the solar disk and the refraction as established in the Explanatory Supplement to the Astronomical Almanac or in the formula of Meeus (correct with 0.01454=sen(50 ') and not with 0.1454 :-) ) Different it is however the case of the ancients: I don't think that it is possible, even if it seems opportune and natural, to make the hypothesis that you do and to suppose that they used the upper bound of the Sun to calculate the instant of dawn from which to begin to mark the temporary hours in the sundials. Obviously also they saw and knew that the Sun disappears when its superior edge goes under the horizon, but I do not know any proof that they used this instant as the beginning of the hours in their drawings and plans of sundials. The fact that, for ignorance or for greater facility of execution, they used a more simplified model of the reality, can be seen also in all the Roman sundials that were produced ( we think) following the methods of the analemma (or projection of the celestial vault), described very clearly by Vitruvius (De Architectura, liber IX) Vitruvius in all his description makes reference to the Sun as to a point, he speaks of single rays that pass for the center, etc.. He also uses ulterior geometric simplification supposing the ecliptic inclination = 24deg = 360/15, whose construction can be found in the Euclids Elements . In my opinion is not true what you assert "there is no proof of the use of the center of the Sun before 900", but it is exactly the contrary , that is "it doesn't exist any proof that the sundials from around 300 BC, till around 1800 AC, has been calculated considering the instant of the true sunset (upper bound, etc.) and not that of the ideal one, with the Sun taken as punctiform" For what I know, also today no one calculates the sundials according to your direction. Some times, for very great sundials, the refraction is considered, but in all the other cases, either for simplicity of shape, either for love of the straight lines, and certainly not for the difficulty in the calculations, all take the Sun as puntiform. The error is very small and comparable to that caused inevitably by the fact that the year is long not a whole number of days, for which in a same day in following years the declination of the Sun changes slightly. Obviously in the Ephemerides we find the exact instants of the dawn and of the sunset of the Sun and if someone (?) uses these values to plan a sundial with ancient hours (Temporary, Italic, Babylonian) he doesn't use the method of our predecessors and he will not obtain courses of the lines as those of the ancient sundials that he wants to reproduce. I don't know anyone that acts in this way, when the formula already written by Fer de Vries is very simple, while the instants given in the almanacs are in Standard and not in Solar Time and moreover they are never given for the place that interests us, since this values change with the latitude. A regard Gianni Ferrari 44° 39' N 10° 55' EMailto : [EMAIL PROTECTED]
Re: R:
Hi Lucio,
Thanks for your note but I don't agree with your
argument.
In all books about gnomonics, old and new, temporal
hours, Italian hours, Babylonian hours and so on are based on the formula
for half the daylength T :
cos T = - tan phi tan decl.
This means that all calculations and constructions
are based on the center of the sun.
Of course it is easy to calculate with respect to
the limb of the sun now we have computers to help us but to my opinion this
isn't usualy done in gnomonics.
In our daily life indeed the sunrise
and sunset is calculated with respect to the limb of the sun. But gnomonics
isn't used in our daily live and I prefer to act in
the historical way.
Best wishes, Fer.
Fer J. de Vries
De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl
Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven,
Netherlandslat. 51:30 N long. 5:30
E
- Original Message -
From:
Ing. Lucio Baruffi
To: Fer J. de Vries ; Noam Kaplan ; sundial
Sent: Sunday, September 26, 2004 6:15
PM
Subject: R:
I am worthwhile with how much you write, to exception of the following affirmation:
"Temporal hours are calculated in respect to the center of the sun as we do
for other time systems".
The hours temporarie, italic and babiloniches are reported to the sunset or
to the sunrise; the sunset and rising are, for definition, reported to the
superior limb of the Sun; therefore it is inaccurate to refer to the center of
the Sun and this yeld to an error of about 4 minutes.
Being complicated to establish the transit of the center of the Sun on the
line of the horizon is unlikely, neither it results me, that followed this
method in the antiquity when instead it is simple to refer to the superior
edge.
Best wishes, Lucio
-Messaggio
originale-Da: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]Per conto di Fer J. de
VriesInviato: venerdì 24 settembre 2004 12.22A: Noam
Kaplan; sundialOggetto: Re:
Hi Noam,
Of course the refraction effects the hourangle
of all the time systems we use in dialling.
But also keep in mind the historical meanings
of used systems as the temporal hours.
Temporal hours are calculated in respect to the
center of the sun as we do for other time systems.
The times of sunrise and sunset however are
calculated for the limb of the sun.
Should we care about that either?
We want to have time in seconds and even in
smaller parts.
But in older days the feelings about time was
much different.
Temporal hours were used as a period of time
peolple was in, not an exact moment of time as we often use.
Calculating the temporal hour lines shows that
the lines aren't straight but sligthly S-shaped which is best visible with
increasing latitude but in older dials
the lines are drawn as straight lines.
It's good to think about the effect of
refraction but in general I should say, forget the refraction in
dialling.
Best wishes, Fer.
Fer J. de Vries
De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl
Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven,
Netherlandslat. 51:30 N long.
5:30 E
- Original Message -
From:
Noam
Kaplan
To: sundial@rrz.uni-koeln.de
Sent: Friday, September 24, 2004
12:30 AM
Can anyone answer this?
If this is the wrong forum, I
apologize.
I have a calculation to figure out the
atmospheric refraction from Fred Sawyer's article in the NASS Compendium.
It is based on calculations that Meeus brings in his book. Refraction
changes the apparent altitude of the sun, thereby changing both the
apparent declination and apparent hour angle of the sun.
Am I making a mistake when I use the apparent
declination and apparent hour angle for the temporal hour
calculation?
The effect of a few seconds difference
for atmospheric refraction on the hour angle seems to have a much
bigger effect on the temporal hours.
Thanks for any help you can
offer,
Noam
My calculations can be seen on the web at
http://www.riets.edu/stuff/suncalc/zman.js
in the function
temporal(localTime)
Re:
Hi Noam, Of course the refraction effects the hourangle of all the time systems we use in dialling. But also keep in mind the historical meanings of used systems as the temporal hours. Temporal hours are calculated in respect to the center of the sun as we do for other time systems. The times of sunrise and sunset however are calculated for the limb of the sun. Should we care about that either? We want to have time in seconds and even in smaller parts. But in older days the feelings about time was much different. Temporal hours were used as a period of time peolple was in, not an exact moment of time as we often use. Calculating the temporal hour lines shows that the lines aren't straight but sligthly S-shaped which is best visible with increasing latitude but in older dials the lines are drawn as straight lines. It's good to think about the effect of refraction but in general I should say, forget the refraction in dialling. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: Noam Kaplan To: sundial@rrz.uni-koeln.de Sent: Friday, September 24, 2004 12:30 AM Can anyone answer this? If this is the wrong forum, I apologize. I have a calculation to figure out the atmospheric refraction from Fred Sawyer's article in the NASS Compendium. It is based on calculations that Meeus brings in his book. Refraction changes the apparent altitude of the sun, thereby changing both the apparent declination and apparent hour angle of the sun. Am I making a mistake when I use the apparent declination and apparent hour angle for the temporal hour calculation? The effect of a few seconds difference for atmospheric refraction on the hour angle seems to have a much bigger effect on the temporal hours. Thanks for any help you can offer, Noam My calculations can be seen on the web at http://www.riets.edu/stuff/suncalc/zman.js in the function temporal(localTime)
Re: Need Behrendt Article
Fred, John,
Another article is :
BEHRENDT H., Alte Fenstersonnenuhren , in "Alte Uhren", n.2,
Monaco, 1980.
I don't know this article and the one you
mentioned.
Fer J. de Vries
De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl
Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven,
Netherlandslat. 51:30 N long. 5:30
E
- Original Message -
From:
Fred Sawyer
To: Fer J. de Vries ; John
Carmichael ; Sundial List
Sent: Wednesday, September 08, 2004 11:44
PM
Subject: Re: Need Behrendt Article
John,
One more article not in Fer's list:
Behrendt, Hans..Glas-Sonnenuhren -
Bestandsaufnahme alter Scheiben..12(3):109 +. This was obviously much earlier than the other 3 articles in
volumes 19, 23 and 29.
Fred
- Original Message -----
From:
Fer J. de Vries
To: John Carmichael ; Sundial List
Sent: Wednesday, September 08, 2004
3:44 PM
Subject: Re: Need Behrendt
Article
Hi John,
An article of Behrendt is in
Schriften der Feunde Alter Uhren
Band XXIX, 1990
page 175 - 190.
Title: Alte englische Fenstersonnenuhren
(II).
In Band XXIII, 1984 another article of Behrendt
about glass sundial was published,
page 157 - 164.
Title: Alte englische
Fenstersonnenuhren.
And finaly in band XIX, 1980 he wrote the
article with title
Historische Glassonnenuhren,
page 161 - 178.
This is history in reverse.
Which copies you have?
Best wishes, Fer.
Fer J. de Vries
De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl
Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven,
Netherlandslat. 51:30 N long.
5:30 E
- Original Message -
From:
John Carmichael
To: Sundial List
Sent: Wednesday, September 08, 2004
8:01 PM
Subject: Re: Need Behrendt
Article
p.s.
All I know about this publication is that it
came out in 1990. On his videotapes he calls it ""Neuzeitliche
Glassonnenuhren".
But It might have been published originally
with this title:
"Alte englische Fenstersonnenuhren II" Schriften der "Freundealter
Uhren" Heft XIX"
I do not know where his articles were
published.
thanks
John
- Original Message -
From:
John Carmichael
To: Sundial List
Sent: Wednesday, September 08, 2004
10:04 AM
Subject: Need Behrendt
Article
Hello Dial Historians:
We are looking for an article written in
1990 by the German stained glass sundial historian, von Hans
Behrendt. It's the third of three articles that he wrote. He
later made videotaped movies of the sundials that were in his
articles. It's very important to us, since he documents many rare
and lost historic stained glass sundials from all over Europe, including
some English ones that you English guys have never discovered!
Some date to the 1500s. He even discovered the lost Victorian
English dials. So this is very important for historical
reasons.
It's called: ""Neuzeitliche Glassonnenuhren".
thanks a lot if any of you have a
copy. Would my German friends pass along this request to the other
German dialists? If anybody has an English translation of it, it
would save Dave and I a lot of work.
thanks again,
John Carmichael
John L. CarmichaelSundial
Sculptures925 E. Foothills Dr.Tucson AZ
85718-4716USATel: 520-6961709Email: [EMAIL PROTECTED]
Sundial Sculptures: http://www.sundialsculptures.comStained
Glass Sundials: http://stainedglasssundials.com
Re: Need Behrendt Article
Hi John, An article of Behrendt is in Schriften der Feunde Alter Uhren Band XXIX, 1990 page 175 - 190. Title: Alte englische Fenstersonnenuhren (II). In Band XXIII, 1984 another article of Behrendt about glass sundial was published, page 157 - 164. Title: Alte englische Fenstersonnenuhren. And finaly in band XIX, 1980 he wrote the article with title Historische Galssonnenuhren, page 161 - 178. This is history in reverse. Which copies you have? Best wishes, Fer. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: John Carmichael To: Sundial List Sent: Wednesday, September 08, 2004 8:01 PM Subject: Re: Need Behrendt Article p.s. All I know about this publication is that it came out in 1990. On his videotapes he calls it ""Neuzeitliche Glassonnenuhren". But It might have been published originally with this title: "Alte englische Fenstersonnenuhren II" Schriften der "Freundealter Uhren" Heft XIX" I do not know where his articles were published. thanks John - Original Message - From: John Carmichael To: Sundial List Sent: Wednesday, September 08, 2004 10:04 AM Subject: Need Behrendt Article Hello Dial Historians: We are looking for an article written in 1990 by the German stained glass sundial historian, von Hans Behrendt. It's the third of three articles that he wrote. He later made videotaped movies of the sundials that were in his articles. It's very important to us, since he documents many rare and lost historic stained glass sundials from all over Europe, including some English ones that you English guys have never discovered! Some date to the 1500s. He even discovered the lost Victorian English dials. So this is very important for historical reasons. It's called: ""Neuzeitliche Glassonnenuhren". thanks a lot if any of you have a copy. Would my German friends pass along this request to the other German dialists? If anybody has an English translation of it, it would save Dave and I a lot of work. thanks again, John Carmichael John L. CarmichaelSundial Sculptures925 E. Foothills Dr.Tucson AZ 85718-4716USATel: 520-6961709Email: [EMAIL PROTECTED] Sundial Sculptures: http://www.sundialsculptures.comStained Glass Sundials: http://stainedglasssundials.com
Re: Freeze Frame Copying?
Hi John, If you have a picture on screen of your computer use the Capture procedure of a second graphic program like Paintshop. There must be many more programs that will have such a capture procedure. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: John Carmichael To: Sundial List Sent: Friday, September 03, 2004 2:03 AM Subject: Freeze Frame Copying? Hello all: Fred Sawyer kindly loaned me 2 German VCR video tapes by Hans Behrent containing amateur movie footage that shows several rare lost stained glass sundials that we do not have on the SGS website. This is the only visual record we have of these historic sundials. He also sent me a transcript of the tapes written in German by Behrent. I need to copy still shots of these sundials shown in the movie but I don't know how to do it other than to take pictures of the TV screen with the VCR on pause. I had a professional movie studio copy them onto a DVD. My computer has a DVD RW and a DVD R and came installed with Dell Media Experience. I can now play the DVD copy of the movie and pause it on a particular frame on my computer, but I can't find a way to copy the frame so that I can send it to Photoshop to make a jpeg of it for the website. Does anybody know how to copy still shots from a DVD? thanks John
Re:
Hi Noa, The answers to your questions 1 and 2 may be found at the web site of De Zonnewijzerkring. Address below. For question 1 follow the links: - calculate and construct - flat sundials/extensive version - secondary procedures and go to pragraph Lines for antique hours or unequal hours. Restriction -66.56 <= phi <= 66.56 The needed formulas are: Calulate half daylength T = arccos( - tan phi * tan decl )Calculate hourangle t = ( u - 6 ) * T / 6 With these formulas you can covert the antique hour u into local suntime angle t. Correction for longitude and equation of time gives the clock time. For question 2 follow the links: - article of the month - archives 2003 - month 03-02 how much time is sundial time Question 3: I don't think the edge of the sun was used to read the time. In antique sundials a shadowpoint was used where to read the time. Such a shadow point can't distiguish between light coming from the edge of the sun and from the center. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: Noam Kaplan To: sundial@rrz.uni-koeln.de Sent: Monday, August 09, 2004 4:47 AM Can anyone help me with these questions? 1) Is there a formula to calculate what time it is on a clock if I know the temporal hour? 2) Also, why does Waugh write that the sun will never shine on a vertical direct south dial before 6 AM or after 6 PM? If sunrise is at 5 AM wouldn't a shadow be cast on a vertical direct south dial? 3) On an ancient (Roman and Greek) sundial was noon shown and defined when the edge of the sun cast a shadow on the noon mark or as in later times when the center hit the mark? Thanks, Noam Kaplan [EMAIL PROTECTED]
Re: On northern vs. southern dials
Hi John, I am not sure for 100% but the round things you saw could be part of the (in 1994 newly reconstructed) meridian of Paris. 135 of these humps shoud be placed on this meridian. It has to do with the Arago monument. Arago (1786 - 1853) was director of the Paris astronomical observatory. The artist Dibbets of the Netherlands won the competition for a new Arago monument. On each hump the word Arago is written. This is what I read in the bulletin of De Zonnewijzerkring, 1995-1 Look at http://www.kunstgeografie.nl/dibbets.htm to see the humps. This is a page in Dutch. There seems to be an idea to make this meridian visible in whole France by planting trees on the line. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: John Carmichael To: sundial@rrz.uni-koeln.de Sent: Sunday, August 01, 2004 3:44 AM Subject: Re: On northern vs. southern dials Hello Jean-Paul When I went to Paris after the Oxford conference, we were driving around the Place de la Concord in a taxi and I noticed several little (about 10 -15cm) round brass mounded humps inlaid in the asphalt. We were going to fast to see if there was anything written on them. I immediately guessed that they might be hour or date markers for the sundial. Has anybody else seen these mysterious little brass markers there? John - Original Message - From: Jean-Paul Cornec To: Sundial, Mailinglist Sent: Sunday, March 03, 2002 5:41 AM Subject: Re: On northern vs. southern dials Anselmo The sundial on the Place de la Concorde in Paris is a classical horizontal sundial with the "Obelisque" as a vertical gnomon. Lines are now more or less erased due a lack of maintenance. There was a scheme with a short explanation in the june 1999 issue of "L'Astronomie". I can scan it and send it to you or to any member of the list; just send me a mail. Regards Jean-Paul Cornec (...) Now that I remember, a kind of touristical question: in this month's issue of the spanish version of Scientific American there is an article by D. Savoie about sundials an in it he says that in the Place de la Concorde in Paris it was drawn a sundial (an Oughtred sundial I suppose) based on the obelisk erected there. Does anybody know if the lines are still drawn or were they erased?
Re: sundial structures
Michael, In the Walt Disney Team Building in Orlando you find a modern sundial of huge dimensions in a cylindrical part of the building, open at top. And a so called mirror dial is in the Lycée Stendhal in Grenoble, France, dated 1673. There are more of those type of dials At the ceiling of my neighbours house is a mirror sundial. In Munich, Germany, the corner of a building is used as gnomon for a sundial on the ground outside. In southern France the construction La Nef Solaire consists of three large sundials in which you can walk around. So the answer to your question is yes, they exist, old and new, inside and outside and there are more than I listed here. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Michael Boyko" <[EMAIL PROTECTED]> To: "sundial list" Sent: Friday, July 23, 2004 6:17 PM Subject: sundial structures > Hello there. > > My name is Michael Boyko, and I am a writer living in > upstate New York. My new book, a long sequence of > prose and poetry, takes place inside a building that > also needs to work as a functional sundial. I don't > know if these sorts of buildings actually exist or > not. That is where you guys and gals come in. Does > anyone on this list know of any building/stadium size > structure that actually functions as a sundial? or a > group of buildings that function together as one? > > Any information would be most helpful, and deeply > appreciated. > > Thanks in advance, > > Michael C. Boyko > > __ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam protection around > http://mail.yahoo.com > - > -
Re: Locus ofintersections in bifilar dial
Hi Peter, I think your calculations may be correct but the scale of the graph isn't. The x axis as in your attached picture has another scale then the y axis. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Peter Mayer" <[EMAIL PROTECTED]> To: "Sundial List" Sent: Thursday, June 10, 2004 2:05 AM Subject: Locus ofintersections in bifilar dial > Hi, > > I've been quietly gnawing on two sundial puzzles for a while now. And > rather than suffer silently, a prisoner of my own inadequacies, I > decided to 'throw myself on the mercy of the court' so to speak. > > Puzzle the first. (I'll leave the second puzzle for another day when I > have the time to set it out with a bit of clarity...) > > > > I've been wondering, idly, for about a year, after having made a mock-up > bifilar dial, what the locus of the intersection of the N-S and E-W > threads is, during the day, and over the course of the year. > > More recently, partly inspired by the fantastic graphics on Fabio > Savian's webpage (www.nonvedolora.it/bifilare.htm) (I finally figured > out what a wonderful pun "non vedo lora" is; or I _think_ I have). So. > I got out my trigonometry books and tried to figure out what the > equations for x and y would be. I couldn't get Fabio's equations 2 and > 3 for x and y to work for me. > > So I went back to the diagram in Fred Sawyer's article "Bifilar > Gnomonics" _Journal of the British Astronomical Association_, Jun 1978, > 88(4):334-351. and _Bulletin of the British Sundial Society_, Feb 1993, > 93(1):36-44, also Feb 1995, 95(1):18-27. (Thanks, once again, Fred for > sending me a copy). After some stumbling around I derived equations for > x and y. And was both pleased, and mortified, to discover that Fred had > presented the same equations later on in his article: > > > > x = g1 sin t/(sin theta tan delta + cos theta cos t) > (10) > > > > y = g2(sin theta cos t - cos theta tan delta)/(sin theta tan delta > +cos theta cos t)(11) > > > > where: theta = latitude; t = solar hour angle; delta = solar > declination; g1 is height of the thread along the y-axis (= 1/cos theta > for a conventional bifilar dial); g2 is the height of the thread along > the x-axis (= tan theta in the usual case). > > > > I then put the equations in a spreadsheet and calculated the x and y > coordinates for a number of hour angles during the day. And repeated > the exercise for different solar declinations. I put the resulting > coordinates into a statistics software package and plotted the results. > (see the attached .gif which is c. 7 kb in size). (I hope the cryptic > legend is sufficiently clear for the purposes of my question) > > At first, I was quite pleased because the resulting family of curves was > roughly what I anticipated, from my conceptualisation of the bifilar > dial as a sort of dial cast by a vertical gnomon. But then arose my > puzzlement. Although the lines though the hour marks converge to a > point (as they should)...the angles _between_ hours are not equal. > Hence my puzzlement. Needless to add, I would be most grateful for an > indication of what am I doing wrong! > > warmest wishes, > > Peter > > -- > Peter Mayer > Politics Department > Adelaide University, AUSTRALIA 5005 > Ph: +61 8 8303 5606 > Fax : +61 8 8303 3446 > e-mail: [EMAIL PROTECTED] > > --- > This email message is intended only for the addressee(s) > and contains information which may be confidential and/or > copyright. If you are not the intended recipient please > do not read, save, forward, disclose, or copy the contents > of this email. If this email has been sent to you in error, > please notify the sender by reply email and delete this > email and any copies or links to this email completely and > immediately from your system. No representation is made > that this email is free of viruses. Virus scanning is > recommended and is the responsibility of the recipient. > > -
Re: Instrument query.
Hi Tony, I looked up in the book The devided Circle by J.A. Bennett. I didn't find Barda but Borda. In your second mail you metioned this name. There is a picture of a Bordan type reflecting circle by Secretian, mid 19th century, radius 135 mm. As written the instrument might be named a reflecting circle or even a repeating reflecting circle. Could this be of help? Best, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "tony moss" <[EMAIL PROTECTED]> To: "Sundial Mail List" Sent: Wednesday, April 21, 2004 6:29 PM Subject: Instrument query. > Fellow Shadow Watchers, >Can anyone direct me to a clear photograph of a > 'Barda Repeating Circle' please? i.e. A modern picture of an actual > instrument rather than a photo-repro' of a contemporary engraving etc. > which I have already. More detail of the scales and mechanical details > is needed. > > Is there an example of this instrument in the UK which might be inspected > at close quarters? If not...where might one be found? > > Tony Moss > - > -
Fw: Publicaci�n de nuestra web de gnom�nica
Dear Friends, I forward an e-mail from Spain about a study of Islamic sundials in Spain. "Estudio y Reconstrucción de la Gnomónica Hispanomusulmana" Even if you have no acces to Spanish or Arabic it is worth to have a look. http://www.alandalus-siglo21.org Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Germán Moreno" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, April 09, 2004 9:44 PM Subject: Publicación de nuestra web de gnomónica > Hola. > > Le escribo para darle a conocer la publicación de nuestra web: > > http://www.alandalus-siglo21.org > > que es sede de nuestro Grupo (al-Ãndalus Siglo XXI). > > Lo componemos Germán Moreno, Marcos Moreno, Jordi Mas. > > Se trata de un monográfico: "Estudio y Reconstrucción de la > Gnomónica Hispanomusulmana" y a la vez mostramos otros de nuestros > trabajos, como los relojes de sol, grabados en mármol. También > damos la opción de adquirir o encargar algunas de las piezas > reconstruidas o algunos grabados en mármol, a un número muy reducido > de personas, como forma de intentar recuperar el gasto invertido en > este proyecto de recuperación del patrimonio artÃstico y cientÃfico > andalusÃ. Además incluimos una serie de artÃculos relacionados con el > tema hispanoárabe y musulmán. > > No es una reseña más o menos breve: es un trabajo extenso y riguroso, > que concluye con la reconstrucción (por vez primera que sepamos) en > mármol de la mayorÃa de los cuadrantes solares hispanoárabes, y una > versión del Relogio de la Piedra de la Sombra, reloj descrito en > los manuscritos alfonsÃes. > > En fin, nos gustarÃa que la visitase y que difundiera la noticia de su > publicación, porque como a toda web que empieza, la publicidad nos viene > muy bien, y cuantos más sepan su existencia, pues mejor. > > Espero sus noticias, y que la disfrute. > > Nos encantarÃa recibir sus opiniones y crÃticas, a través del correo > de la web. > > Un cordial saludo. > > Hasta otra. Germán. > > _ > Horóscopo, tarot, numerologÃa... Escucha lo que te dicen los astros. > http://astrocentro.msn.es/ > > -
Re: Reverse Engineer Oldest SGS
Hi Mac et al, What I did is available for anyone who is interested. A small executable basic program (with source code) for the method with hourlines 6 and 9 or 15 and 18. A small spreadsheet with the method Anselmo told us for input of two other hours. Send me an e-mail and I will send a zipped file of about 30 kB next week. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Mac Oglesby" <[EMAIL PROTECTED]> To: "sundial" Sent: Friday, April 09, 2004 7:13 PM Subject: Re: Reverse Engineer Oldest SGS > > Hello John, Fer, Anselmo, Dave, et al. > > Please continue to cc messages to the Sundial List, so that we can > all share in this very interesting thread. I hope that some method is > worked out so that we can also access any drawings or pictures. > Thanks. > > Best wishes, > > Mac Oglesby > > > > > > > > >Hi Fer, Anselmo and others who gave mathematical formulas for > >reverse engineering: > > > >When I have time after Oxford, I am going to make a Delta Cad > >reproduction drawing of photo of the oldest SGS and I will indicate > >the hour angles of all the hourlines and the angle of the equinox > >line. > > > >Since I am not a good mathematician, I was wondering if I could then > >send you guys a copy of the drawing and you could use your > >formulas on it using my drawing. And I'll use the mathless trial & > >error method using Zonwvlak. Then we could compare the results. > >(latitude and wall declination). > > > >If it's as easy as Fer suggests, then it might be possible to make a > >program or spreadsheet that mathematically challenged people could > >use to analyze other dials with unknown latitudes and declinations. > > > >can we do this? > > > > (big snip) > > - > -
Re: Reverse Engineer Oldest SGS
Hi Anselmo, This is the next step in the problem of John. I made a small spreadsheet with the fomulas you mention but I got for the substyle angle a value four times the real value. I changed: tan(zSS / 2) = 2B / (A^2 + B^2 - 1)into tan(zSS * 2) = 2B / (A^2 + B^2 - 1)and now it runs well. A typo error I think. I have the book of Soler but perhaps an older version because it has less then 395 pages and I don't see the formulas in that book so I can't check what he writes. To John I sent a small basic program to use the method I published on the sundial list. So John is able to start with his job to recalculate vertical dials that show sun time. Martin Bernhardt also published a procedure to recalculate a vertical dial with longitude correction. So for vertical dials we have the solutions complete I think. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: Anselmo Pérez Serrada To: sundial@rrz.uni-koeln.de Sent: Friday, April 09, 2004 12:06 PM Subject: Re: Reverse Engineer Oldest SGS Fer J. de Vries wrote: Hi John, Assuming the sundial is vertical (because the XII hourline is vertical) and assuming the sundial is well made, just measure two angles in the pattern and it is possible to recalculate the latitude and declination of the dial. The angles you need are the hourlineangles for hour 6 and 9 for a morning dial or 15 and 18 for an afternoon dial. There is a more general formula in case you can't measure these hours. I got it from Soler's book, page 395:Suppose that you have the angle z1 for hour H1 and z2 for hour H2, let's defineP = cotg(H1) Q = cotg(H2)p = cotg(z1) q = cotg(z2)A = (p-q) / (P-Q)B = (Pq - pQ) / (P-Q)Then you can get (and check!) the substylar angle fromtan(zSS / 2) = 2B / (A^2 + B^2 - 1)and from ittan(LAT) = sqrt( B/tan(zSS) )sin(DEC) = B/tan(LAT) = sqrt( B*tan(zSS) )These formulae are complete general so it's worthwhile taking the effort to type them intoa spreadsheet.RegardsAnselmo
Re: Reverse Engineer Oldest SGS
Hi Dave, The angles indeed are the angles between the noonline and the hourlines on the dial. I think the signs aren't important because at the start all is ^2. And there is symmetry between a west and east declining dial. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Dave Bell" <[EMAIL PROTECTED]> To: "Fer J. de Vries" <[EMAIL PROTECTED]> Cc: "John Carmichael" <[EMAIL PROTECTED]>; "Sundial List" Sent: Wednesday, April 07, 2004 5:01 PM Subject: Re: Reverse Engineer Oldest SGS > On Wed, 7 Apr 2004, Fer J. de Vries wrote: > > > Assuming the sundial is vertical (because the XII hourline is vertical) > > and assuming the sundial is well made, just measure two angles in the > > pattern and it is possible to recalculate the latitude and declination > > of the dial. > > > > The angles you need are the hourlineangles for hour 6 and 9 for a > > morning dial or 15 and 18 for an afternoon dial. > > The only clarification I might ask for is, exactly what you mean by the > hourline angles. I would expect them to be measured from the Noon line, > returning positive angles (in either morning or afternoon cases?) Is that > correct? > > > The formulae: > > I name the houline angles for an afternoon dial z15 and z18. > > Calculate: > > > > A = ( cot z15 - cot z18 ) ^ 2 > > B = ( cot z18 ) ^2 > > a = B > > b = A + B -1 > > c = -1 > > > > Calculate y1 and y2 from : > > > > (-b +_ SQRROOT(b^2 -4ac)) / (2a) > > > > (A well known formula I think so typing it like this you should understand it.) > > (Only the positive y is interesting for our problem)) > > Well, y2 might be useful for imaginary dials! > > > Now calculte the latitude and declination from > > > > cot lat = sqrroot y > > > > sin decl = cot z18 . cot lat > > > > I learned this in 1988 from Mr. Martin Bernhardt, Germany after I once > > made an iteration progam for a calculator to solve this question. > > > > I hope I didn't made a typing error but try it. > > > > Bernardt wrote more about these problems but for the problem you have > > the above solution will do for many examples I think. > > > > Bet wishes, Fer. > > Dave Bell > 37.277N 121.966W > -
Re: Reverse Engineer Oldest SGS
Hi John, Assuming the sundial is vertical (because the XII hourline is vertical) and assuming the sundial is well made, just measure two angles in the pattern and it is possible to recalculate the latitude and declination of the dial. The angles you need are the hourlineangles for hour 6 and 9 for a morning dial or 15 and 18 for an afternoon dial. The formulae: I name the houline angles for an afternoon dial z15 and z18. Calculate: A = ( cot z15 - cot z18 ) ^ 2 B = ( cot z18 ) ^2 a = B b = A + B -1 c = -1 Calculate y1 and y2 from : (-b +_ SQRROOT(b^2 -4ac)) / (2a) (A well known formula I think so typing it like this you should understand it.) (Only the positive y is interesting for our problem)) Now calculte the latitude and declination from cot lat = sqrroot y sin decl = cot z18 . cot lat I learned this in 1988 from Mr. Martin Bernhardt, Germany after I once made an iteration progam for a calculator to solve this question. I hope I didn't made a typing error but try it. Bernardt wrote more about these problems but for the problem you have the above solution will do for many examples I think. Bet wishes, Fer. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E-Original Message-From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]On Behalf Of John CarmichaelSent: April 6, 2004 8:53 AMTo: Sundial ListSubject: Reverse Engineer Oldest SGS Hello All, I'm trying to "reverse engineer" the oldest known stained glass sundial (made in 1529) so that I can determine the area in Germany for which it was designed and the window's declination. All we know about the design location of this dial is that it came from "somewhere in Germany". (I wonder what a map of Germany looked like in 1529?). Claude Hartman just wrote an article in the new Compendium (march 04) comparing vertical sundials with drawings of dials at different latitudes and declinations. His article gives many clues to the solution of this problem. Just remember that his article is for normal vertical wall dials, not stained glass. So to view his sundial face drawings as if they were stained glass, you have to view his article reflected from a mirror! We should be able to determine the latitude and wall declination fairly easily since the dial has declination lines. Looking at the slope of the equinox line will tell us the wall's declination. (To do this, I'm going to make a bmp. of the photograph and import it into Delta Cad, then I'll draw line on top of the equinox line and will measure it's exact angle) I will retrace all the hour lines the same way until I get a complete Delta Cad drawing of the sundial face. Now I'm stuck. How do I determine longitude? If it were a modern sundial corrected for longitude, the answer would be simple. I'm thinking that it's impossible to determine its longitude. As for its latitude, I should be able to determine that from the hour angles of the hourlines. Right? The traced Delta Cad drawing with the angle dimension tool will tell me the precise hour angle of each line. Now I'm stuck again and don't know a mathematical solution so instead of using math, I'm wondering if I should just start feeding in different latitudes of Germany into Shadows Sundial Generator or Zonvwlak of vertical dials of this window's declination until I find, by trial and error, a drawing that best matches the sundial face and that would be its latitude. This isn't a very scientific approach I know, but I'm not as smart as you guys. Would one of you have a better way to reverse engineer this dial? thanks John John L. Carmichael Jr.925 E. Foothills Dr.Tucson Arizona, 85718 USATel: 520-696-1709Email: [EMAIL PROTECTED]Sundial Sculptures Website: http://www.sundialsculptures.comStained Glass Sundials Website: http://advanceassociates.com/Sundials/Stained_Glass
Re: News from the new dial at 78 degrees North!
To all who concerns, Congratulations with the beautiful sundial in the North of Norway. How nice is the international cooperation from people all over the world to make a sundial fot the community in this part of the world. I enjoyed reading the story about it. Best wishes, Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: Louise Rigozzi To: sundial@rrz.uni-koeln.de Sent: Thursday, March 18, 2004 8:19 PM Subject: News from the new dial at 78 degrees North! Hi everyone, Thanks to Anne for letting you know about the new sundial in Longyearbyen, Svalbard. It appears to be the world's most northerly at present. It was designed by myself and made in collaboration with Tony Moss of Lindisfarne Sundials. It was inaugurated on 6 March - while the ceremony was going on, two polar bears were making their way towards the shoreline - they obviously thought it started at 2.30 instead of 2'o'clock! They then had to be scared away with explosions. It was certainly an exciting moment when the sun arrived the following day, one day earlier than scheduled (due to the leap year), and reached the dial's face for the first time. Tony was up here and had roughly 20 minutes to make the final alignment. Please accept my apologies for the site being a bit slow to download - it is my first attempt at a website, and I have put photos in the wrong folders. I will be working on this this weekend, so it should become quicker after that. I also want to add more text and more photos. Please feel free to sign the guestbook, and correct any errors in the text (a private entry might be best for this!). Thanks - if you feel just a little of the excitement I have felt at watching the dial working over these last 10 days, then you'll be feeling pretty good! Yesterday the sun reached the dial for five hours, just 10 days after its first appearance - is this a totally amazing place or what? It has been suggested that I set up a tent next the dial by people who have been watching my obsessive behaviour. I would, of course, it it wasn't for the minus 36 degree windchill today. Hope you enjoy the site and don't die from boredom while it downloads, Louise Rigozzi (www.longyearbyen.net/sun) Stay in touch better and keep protected online with MSNs NEW all-in-one Premium Services. Find out more here. -
Re: Advantages and disadvantages by dial type?
Hi John, A hemispherium is a mirror of the sky and all (great)circles on the sky are circles in the dial. Once a friend said, holding a hemispherium: I have the heaven in my hands. Therefore a hemispherium is one of the beautiest sundials. Roger Bailey already pointed to my page on the Internet how to construct a hemispherium. The construction isn't the problem but how to make a good hollow ball. I could buy some plastic bowls to hold plants. But many more hollow bodies can be used by cutting them with an horizontal plane. Such bodies than can be used for a full day sundial. The easiest one is a box. Also the horizontal sundial can't show all day what you want to be showed. As the sun is near the horizon the shadow of a nodus is very far away and can't be catched by a dial of limited size. But if you place a horizontal dial in a box of water ( or make is with perpex ) you get an all day sundial because the horizon then is a circle nearby. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: <[EMAIL PROTECTED]> To: Sent: Tuesday, March 09, 2004 10:16 PM Subject: Advantages and disadvantages by dial type? > I was thinking about another dial, one that does date and > time whenever the sun is up. I came to the conclusion that > a hollow hemisphere with its lip in a horizontal plane and > nodus at the center of the hemisphere would do it, and might > not be too difficult if I could make the hemisphere from > something commonly available. Assuming you wanted just > Local Apparent Time, would all the date and time lines on > the inside of the partial sphere be great circles? That > fact, if it is a fact, might make construction fairly easy. > > Then I wondered if there is another type of dial which will > give date and time whenever the sun is up. So I started > trying to find a list of advantages and disadvantages of > different dial types. > Something like: > - horizontal garden dial - good anytime sun is up, generally no date, but limited date with nodus > - equatorial dial - good only from 6 to 6 else won't show some hours at equinoxes, generally no date > - equatorial-cylindrical with nodus bead - can do all dates and times if top is cut off level with nodus? > - armillary dial - blocks itself at times > - nodal dial, time & date on horizontal plane - sometimes the time/date are impractically distant from the nodus > - nodal dial, time & date on part of sphere - does it all and it maintains constant shadow size > > I looked around for such a list, and of course visited Frans > Maes' site where I found the following passage - > > Frans writes: > "The most natural type of dial is the nodal sundial. The > shadow of any fixed point traces a projection of the above > pattern on the background, the dial face. That may be a > hollow sphere, in which case the projection is a 1:1 > replica. That type of dial was known already in Antiquity. > Other shapes are easier to produce, like a hollow cone, or a > plane surface of arbitrary orientation. The principle is > the same, though." > > So it sounds like a portion of a sphere with nodus has been > around a long time, but it's not made often because it's too > difficult. Is that correct? > > Is this sundial close to ideal? > Frans Maes' site > http://www.biol.rug.nl/maes/zonnewijzers/welcome-e.htm > nodal dial > Smit Transformer Manufacturing Co., Nijmegen > > Thanks, > John Bercovitz > > - > -
Re: sundial for the blind
Dear Sara, In The Netherlands there is sundial for blind children in Zeist. (1991) It is based on an equatorial disk that is rotated by hand until an electronic device finds the sun and gives a beep. Braille marks are used to read the sundial. On our WEB site (address below) follow the links: Sundial of the month Archives 2003 03-08, Zeist. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: Sara Schechner To: Sundial List Sent: Sunday, March 07, 2004 3:52 PM Subject: sundial for the blind Hi there,My community, Newton, Massachusetts, has a number of prominent schools for the blind and a strong public commitment to inclusion of people of all needs. I have just received an interesting commission to create a sundial for the vision impaired. It is part of a new outdoor community classroom and playground designed to be accessible to kids and adults with special physical needs that will anchor an older, major athletic complex of active playing fields. I will briefly describe the playground and community classroom below (with excerpts from the projects' websites and flyers). When the sundial was announced, I went to City Hall to make sure that it would be a properly working sundial. After all, the project is on a field that used to be the farmland that belonged to my old house! When the budget for the sundial was going to cut, I returned to the City commissioners and gave such an impassioned plea for the cultural and educational benefits of sundials (in the name of NASS and sundial societies everywhere) that the dial project was restored with great enthusiasm. I was selected as designer and the project evolved from a routine sundial into a sundial for the blind. Do members of the Sundial List have any ideas on how to accomplish this goal? One idea I had is to use a glass sphere that will focus sunlight on an equatorial band with raised numerals that would get hotter than the surrounding numerals when heated by the sunlight. Thanks for your advice and support!Sara SchechnerGnomon ResearchWest Newton, MA =The PlaygroundThe Albemarle Playground Project is Newton's fully accessible playground for children and their adult caregivers. The playground and tot lot are accessible by wheelchair and walkers. It has special playground equipment for use by kids with limited body strength and the equipment is of high contrast colors and diverse textures to aid the vision impaired. The fabulous thing about the playground is that it also appeals to kids without these needs, and permits all the children to play together. No one feels singled out or isolated. The Outdoor Community ClassroomThe Classroom, which will feature a gazebo, benches, tables, a drinking fountain and a sundial, will provide a fully accessible, multi-generational passive recreation space. It will provide a permanent yet flexible space for a variety of activities enjoyed by persons of all ages. The Community Classroom will facilitate the enjoyment of the out-of-doors, both for those for whom the outdoors location is central to their activity (or example, a bird watching group or nature photography club) as well as for those for whom the natural setting is an enhancement of their activity (for example, a senior citizens' crocheting club or a book discussion group.) Third graders might meet there as they begin their study of the tadpoles in Cheesecake Brook, while a seventh grade English class might use the space for poetry reading. Two friends might break from their early morning power walk and sit and talk for a while, or two pre-schoolers might "take the stage" and put on an impromptu performance. Benches located close to the tot lot enclosure will allow our seniors a chance to do some toddler watching, without finding themselves in the middle of the toddler action!The Community Classroom will provide passive recreation space within what is otherwise a large recreational complex devoted to active recreation. This accessible passive area will provide a sense of balance lacking in the present complex configuration. It will also facilitate enjoyment of surrounding open space, including Cheesecake Brook, the Charles River and adjacent conservation land. The Community Classroom will also provide the complex with "street presence", anchoring the playground and playing fields. Carefully planned and constructed, the organizers believe that the Community Classroom will serve Newton well for generations to come. The following quote from Rachel Carson expresses the spirit behin
Re: sundial inside a room
Ronitz, Make a mirror in the window-sill and draw the hourlines on the ceiling and walls. Place the mirror inside and the refraction of the glass may be disregarded. The program ZW2000 calculates such mirrir dials. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: Ronit Maoz To: SUNDIAL MAILING LIST Sent: Friday, January 02, 2004 3:25 PM Subject: sundial inside a room Dear members, I would like to create a sundial inside a room, using the sun rays passing through (a) window(s). Can anybody help me achieve this goal? Sincerely, Ronit Maoz
Re: R. Glynne Smithsonian dial replica
Hi Woody, Great you have a copy of the Glynne replica. About Glynne I have the text: -- Richard Glynne (1681-1755), was apprenticed to Henry Wynne in 1696 in the Clockmakers' Company of which he became free in 1705 and was steward in 1725. He worked first at the sign of the Atlas and Hercules (1712-16) In Cheapside and subsequently (1718-29) opposite Salisbury Court in Fleet Street, London. On obtaining his freedom in 1705, he married Anne Lea, the daughter of the noted map and globe-sellers Philip and Anne Lea. From at least 1712 he was working in association if not in formal partnership, with his mother-in-law, advertising a new pair of globes in 1712, and publishing and marketing maps. In parallel with this activity, he made and sold 'all sorts of Mathematical instruments, either for Land or Sea, according to the newest improvements' as he stated in an advertisement in 1726. A variety of mathematical instruments by Glynne are indeed known. All are of high quality, with clean, well executed engraving uncluttered by extraneous decoration. Glynne's fine instruments recommended themselves to a fashionable clientèle, and he was sufficiently successful to be able to retire at the relatively early age of 49 in 1730, his stock being auctioned at the shop of the optician Edward Scarlett in the same year. -- In the early 1980's a small Dutch company wanted to make replicas of this dial. They got good technical photographs of the Smithonian but wanted a new drawing for production of the dial. I took the challenge and made the drawing by hand, scale 1:1. At that time I had no computer to help me. Beneath the gnomon you find my name and the date 1982(?) I had a problem with the minute marks so I made 2 minute marks. One minute marks looked irrigular when I tried to draw them. I had nothing to do with the production and some went wrong. The angle of the gnomon is too large. As I remember I calculated the dial for 51.5 degrees. The gnomon isn't thick enough. Look at the gap at noon. As I noted that the dial was rather glimmy the answer was "That sells better." I only once made such a drawing by hand. It was a nice job once, I won't do it a second time. Best wishes for now and 2004 with a lot of sun for our dials. Fer. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: "Woody Sullivan" <[EMAIL PROTECTED]> To: <sundial@rrz.uni-koeln.de> Sent: Sunday, December 28, 2003 11:32 AM Subject: R. Glynne Smithsonian dial replica > For Christmas I've just received a nice-quality brass replica > of a 30-cm diameter horizontal dial. It's inscribed "R. Glynne fecit" > and the equation of time table gives evidence that it's on the Julian > calendar, which England did not abandon until 1752. Measuring the > gnomon angle, I derive a design latitude of 54.3 deg, and from the > angles of the hourlines, I get a design latitude of 52.5 deg (plus or > minus 1 deg). This latter is consistent with London at 51.5 deg > latitude.> > Does anyone know of the provenance of the original, which was > apparently made by Mr. Glynne in England in the early 18th or late > 17th c?> > Thanks and with best wishes to all for a peaceful 2004,> > Woody Sullivan> **> Prof. Woodruff T. Sullivan, III Center for Astrobiology & Early Evolution> Dept. of Astronomy Box 351580> Univ. of Washington tel. 206-543-7773> Seattle, WA 98195 USA fax 206-685-0403> ->
Re: Analemmatics update
Hi Frans, Dat is weer wondervol nieuws over analemmatische zonnewijzers. Je web site wordt zo een bijzonder mooi naslagwerk. Prettige festdagen en tot ziens. Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Frans W. Maes" <[EMAIL PROTECTED]> To: "Sundial List" Cc: ; "François" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Friday, December 19, 2003 1:47 PM Subject: Analemmatics update > Hi all, > > Those of you interested in analemmatic dials might like to have a look at > some new or updated pages. > > 1) A split-analemma analemmatic dial, designed by Len Berggren and Brian > Albinson, at a Simon Fraser University parking lot. See: > http://www.sfu.ca/mediapr/sfu_news/archives_2003/sfunews10300310.htm > This is the first analemmatic sundial in Canada incorporating the Equation > of Time correction. It is similar in this respect to the famous sundial in > Longwood Gardens (Kennett Square, PA, USA), see: > http://www.longwoodgardens.org/Sundial/Analemma.html > This precision instrument certainly deserves a more prominent location and a > more permanent construction! > > 2) The analemmatic dial in the grounds of Mount Stromlo Observatory, near > Canberra (Australia). It survived the bushfires that ravaged the Observatory > last January, which destroyed all telescopes and many buildings and > instruments. > > 3) A local committee has teken pity of the unique sundial at the Observatory > of Besançon (France), which was in bad condition. It is the world's third > oldest analemmatic dial and the only one that shows Julian (astronomical) > hours. The Committee is well underway raising funds for its restoration. > Your support is also appreciated. > > For these pages, follow the links in the "New or updated" box at my sundial > site: > www.fransmaes.nl/sundials/ > > Best regards, > Frans Maes > 53.1N 6.5E > > > - > -
Re: Paper sundials
Hi Tom, To make your personalized dial try to make .dxf files of both and combine them in one drawing program. Another easy way is to use Deltacad and its macro's. There are macro's available at the NASS web site for both types of sundials. Make changes to the basic output as you like to get your combined drawing Best wishes, Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Tom Egan" <[EMAIL PROTECTED]> To: "Sundial Mailing List" Sent: Tuesday, November 25, 2003 3:36 AM Subject: Paper sundials > I'm looking for a program that will allow me to print out on one piece > of paper an analemmatic and a horizontal sundial. This allows the user > to find the correct time and true north by rotating the paper in the > horizontal plane until both dials read the same time. > > I know I can get a canned version of this at axum.tripod.com but I want > to be able to personalize it as I could at John Hoy's page. (I'm > thinking of making some of these for holiday gifts for friends.) I > tried John Hoy's URL from March 2000, but it was "Not Found on this > server" as of today. A thread from back then is appended below. > > Can anyone point me to a working site or program for such a combination?. > > Tom Egan > 33.642N 117.943W > -- - > I forgot to include the url of my webpage in my previous post about paper > sundials. It's www.cyberspace.org/~jh/dial/ > I've been told that that url isn't working but it's correct so the server > must have been temporarily down. > > The other url I've plugged in the past, axum.tripod.com, is no longer > sundial specific. > > Best, > > John > > On Sun, 19 Mar 2000, john hoy wrote: > > > Fellow dialists, > > > > I've revised my webpage and finally managed to get the output of my > > PostScript sundial programs into the gif and PDF formats so if any of you > > tried unsuccessfully in the past to see them I invite you to try again. > > > > > - > -
Re: Foster-Lambert dial
Hi John, You are right saying "Wow, that's neat Mac", because it is a beautifull peace Mac made of the Foster Lambert sundial with EoT correction. But it isn't the first example ever made as you bet. Such a dial was constructed by Thijs de Vries, Netherlands, around 1978 but not so beautiful as Mac's. No doubt Mac will point to this in his article for Compendium. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "John Carmichael" <[EMAIL PROTECTED]> To: Sent: Saturday, November 15, 2003 6:19 PM Subject: Re: Foster-Lambert dial > Wow, that's neat Mac. I never thought anybody would actually get around to > building one. I bet it's the first Foster-Lambert dial ever constructed > since It's got a face only a true dialist could love (or understand)! It's > nice to see how you always seem to tackle those odd theoretical dial types > we often see in the Compendium and make them into actual working dials. I > still have on my workbench the little interactive string shadow plane dial > that you gave us all at the conference in Hartford. > > John > > John L. Carmichael Jr. > 925 E. Foothills Dr. > Tucson Arizona, USA > Tel: 520-696-1709 > Email: [EMAIL PROTECTED] > Sundial Sculptures Website: http://www.sundialsculptures.com > Stained Glass Sundials Website: > http://advanceassociates.com/Sundials/Stained_Glass > - Original Message - > From: "Mac Oglesby" <[EMAIL PROTECTED]> > To: > Sent: Saturday, November 15, 2003 9:33 AM > Subject: Foster-Lambert dial > > > > > > 15 Nov 2003 > > > > Hello friends... > > > > After six months of months of research, design, and construction > > (yes, I work slowly ), my Foster-Lambert sundial saw the Sun for > > the first time on 9 Nov 2003. The central white disk holding the hour > > points measures 24 inches in diameter. > > > > I've posted a montage of four small pictures at > > > > http://www.sover.net/~oglesby/Foster-Lambert/ > > > > I you click on the filename F-L photos 9Nov03.jpg (not on the icon), > > it should open for you. Please let me know (off list) if you have > > difficulty viewing the file. > > > > I'm planning to submit an article about this dial to The Compendium, > > giving details of the design and construction, along with a better > > photo. > > > > Best wishes, > > > > Mac Oglesby > > - > > > > > - > -
Re: Shadows 2.0
Francois, I downloaded the beta version of Shadows version 2. I see a number of options is locked. Can you send me the key to unlock these possibilities? Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "FranÁois Blateyron" <[EMAIL PROTECTED]> To: Sent: Sunday, October 19, 2003 10:20 PM Subject: Shadows 2.0 > Dear all > > I finally managed to update the english part of my web site! I completely > rewrote the site (the content remains approximatively the same but the look > is different). > The main difference in the content is about the Shadows program: the new > version 2.0 is now available and I wrote a new set of pages to describe its > features. > > I invite you all to visit it and send me your remarks about this new > version. It is still a beta but very close to the final version. > Go to www.shadowspro.com > > Thanks. > > Francois Blateyron > www.cadrans-solaires.org > www.shadowspro.com > > > > > > - > -
Re: Sundial bridges
Willy, No doubt it is a nice tower but to mention it a sundial is overdone. There is written: The orientation of the tower means that the shadow of the central needle on the circular platform acts as a (rather impractical) sundial. It's a vertical needle and an horizontal ring. That could be a horizontal sundial at the pole but Barcelona is in Spain. Best, Fer. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: "Willy Leenders" <[EMAIL PROTECTED]> To: <sundial@rrz.uni-koeln.de> Sent: Tuesday, October 07, 2003 10:55 AM Subject: Re: Sundial bridges > For an other sundial integrated in a construction designed by the architect> Santiago Calatrava see> > http://www.galinsky.com/buildings/MontjuicTower/> > Willy Leenders> Hasselt, Flanders in Belgium> > > Megan Paris wrote:> > > I am interested in finding out about the use of architecture/engineering> > elements acting as sundials, especially as regards bridge construction. I> > know that the architect Santiago Calatrava is designing a 'Sundial Bridge'> > in Redding, CA , with an inclined tower acting as a gnomon. Do you know of> > any other examples of this?> >> > Kind regards,> > Megan Paris> >> > -> > ->
Re: Possible serious flaw in Shadows 1.6.4?
Hi François, Glad the problems are solved now. I didn't realize a newer version was there. The program runs now without the error John and I had. Thanks for your help. Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "François Blateyron" <[EMAIL PROTECTED]> To: Sent: Friday, September 19, 2003 9:26 PM Subject: Re: Possible serious flaw in Shadows 1.6.4? > Hi Fer > > Thank you for this picture. It shows me the problem while on the version I > have on my PC, I don't see it ! > > In fact, if you look at the History page on my web site, you can see that > this bug has been found and fixed 5 days after the release of version 1.6.4! > John (and you Fer) must use the version 1.6.4 build 1884 generated on > February 28th, 2002, while the latest version is the 1.6.4 build 1887 > generated on March 3rd, 2002. I didn't changed the version as it was fixed > immediately after the first release (I thought very few people had download > it meanwhile). So, if you download the latest version, it should fix the > problem. > > To avoid such problems, it is recommended to visit my web page from time to > time. I plan to install an automatic function in the new version 2.0 in > order to detect if a new version is available (it will work only if an > Internet connection is open). > > I have been very busy by my job the past months and unfortunately I didn't > have much time to read this excellent mailing list, or to work on my > program. Nevertheless, this summer, during week ends and few days of > holidays (unfortunately only 2 weeks of holidays), I have continued to > refine the new version 2.0 of Shadows. You might be interested to try it. > Just go to http://www.cadrans-solaires.org/gb/v2.html and download the test > version 2. > The english help file is currently being translated. You can read the French > version meanwhile (!) and let me know your comments. > > Best regards > > Francois > > > - Original Message - > From: "fer j. de vries" <[EMAIL PROTECTED]> > To: > Sent: Thursday, September 18, 2003 10:31 PM > Subject: Re: Possible serious flaw in Shadows 1.6.4? > > > > François, > > > > I use version 1.6.4 and I got the error as John mentioned. > > I calculated a vertical dial, declining 45 degrees. > > The result is added ( in a direct mail to François only ) > > The graph of the dial is correct but the line of the substyle isn't. > > So to my opnion John's remark is correct. > > > > Best wishes, Fer. > > > > Fer J. de Vries > > > > De Zonnewijzerkring > > mailto:[EMAIL PROTECTED] > > http://www.de-zonnewijzerkring.nl > > > > Home > > mailto:[EMAIL PROTECTED] > > http://www.iae.nl/users/ferdv/index-fer.htm > > Eindhoven, Netherlands > > lat. 51:30 N long. 5:30 E > > > > - Original Message - > > From: "François Blateyron" <[EMAIL PROTECTED]> > > To: "John Carmichael" <[EMAIL PROTECTED]>; "Sundial List" > > > > Sent: Thursday, September 18, 2003 6:40 PM > > Subject: Re: Possible serious flaw in Shadows 1.6.4? > > > > > > > Hello John > > > > > > I am not sure I understand the problem you have. In the example you > give, > > > for a north-west sundial, you should enter 135° West for the azimuth > > because > > > Shadows has its reference at the meridian (south). > > > Anyway, I have checked for both 45° and 135° and I don't see any > problem. > > > Could you send me screen captures? > > > > > > Thanks > > > > > > Francois Blateyron > > > www.cadrans-solaires.org > > > > > > > > > > > > > > > > > > - Original Message - > > > From: "John Carmichael" <[EMAIL PROTECTED]> > > > To: "François Blateyron" <[EMAIL PROTECTED]>; "Sundial List" > > > > > > Sent: Wednesday, September 17, 2003 12:16 AM > > > Subject: Possible serious flaw in Shadows 1.6.4? > > > > > > > > > > Hello Francois and others: > > > > > > > > Something's been driving me crazy. (more than usual). I think I might > > have > > > > found a rather serious error in the Shadows 1.6.4 sundial generator > > > program. > > > > But I could be wrong and
Re: Possible serious flaw in Shadows 1.6.4?
François, I use version 1.6.4 and I got the error as John mentioned. I calculated a vertical dial, declining 45 degrees. The result is added ( in a direct mail to François only ) The graph of the dial is correct but the line of the substyle isn't. So to my opnion John's remark is correct. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "François Blateyron" <[EMAIL PROTECTED]> To: "John Carmichael" <[EMAIL PROTECTED]>; "Sundial List" Sent: Thursday, September 18, 2003 6:40 PM Subject: Re: Possible serious flaw in Shadows 1.6.4? > Hello John > > I am not sure I understand the problem you have. In the example you give, > for a north-west sundial, you should enter 135° West for the azimuth because > Shadows has its reference at the meridian (south). > Anyway, I have checked for both 45° and 135° and I don't see any problem. > Could you send me screen captures? > > Thanks > > Francois Blateyron > www.cadrans-solaires.org > > > > > > - Original Message - > From: "John Carmichael" <[EMAIL PROTECTED]> > To: "François Blateyron" <[EMAIL PROTECTED]>; "Sundial List" > > Sent: Wednesday, September 17, 2003 12:16 AM > Subject: Possible serious flaw in Shadows 1.6.4? > > > > Hello Francois and others: > > > > Something's been driving me crazy. (more than usual). I think I might have > > found a rather serious error in the Shadows 1.6.4 sundial generator > program. > > But I could be wrong and would love for one of you smart guys to confirm > if > > this is true so I don't lose all my hair. > > > > When it draws a declining vertical dial, it shows with a dashed line the > > base or footprint of the style on the face (the distance between A and B). > > But this is in a very odd position. Point A on the style (the style foot) > is > > correctly placed, but point B (the base of the sundial) is at some > arbitrary > > point whereas it should at the dial's center where the hourlines converge. > > In other words, B-C should be the polar axis but it isn't. > > > > I built a model and placed the style in the possibly flawed recommended > > position. The dial keeps time correctly if you look at the shadow tip > (point > > C) because A is in the correct position below it. But the shadow line of > > the flawed (B-C) polar axis is not parallel to the correct hour line. If > I > > rotate the style about point A so that point B is at the dial's center, > then > > the polar axis shadow looks right. > > > > To test this, using Shadows 1.6.4, try drawing a due northwest vertical > wall > > dial (wall azimuth: 45 deg., inclination: 90 deg.) for Greenwich Great > > Britain (lat: 51* 30', long: 0*) the perpendicular style. The B-C segment > is > > called the polar style. Note the weird position of the line A-B on the > dial > > face. I just can't figure it out. Am I doing something wrong or not > > understanding something? > > > > Thanks > > > > John > > > > > > > > - > -
Re: Possible serious flaw in Shadows 1.6.4?
Hi John, Yes, this must be an oddity in the program. Calculate the same dial as a decling-inclining dial. Because the program translates this to a vertical dial, input for the inclination 89degrees 59 minutes. Then you see the correct position. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "John Carmichael" <[EMAIL PROTECTED]> To: "François Blateyron" <[EMAIL PROTECTED]>; "Sundial List" Sent: Wednesday, September 17, 2003 12:16 AM Subject: Possible serious flaw in Shadows 1.6.4? > Hello Francois and others: > > Something's been driving me crazy. (more than usual). I think I might have > found a rather serious error in the Shadows 1.6.4 sundial generator program. > But I could be wrong and would love for one of you smart guys to confirm if > this is true so I don't lose all my hair. > > When it draws a declining vertical dial, it shows with a dashed line the > base or footprint of the style on the face (the distance between A and B). > But this is in a very odd position. Point A on the style (the style foot) is > correctly placed, but point B (the base of the sundial) is at some arbitrary > point whereas it should at the dial's center where the hourlines converge. > In other words, B-C should be the polar axis but it isn't. > > I built a model and placed the style in the possibly flawed recommended > position. The dial keeps time correctly if you look at the shadow tip (point > C) because A is in the correct position below it. But the shadow line of > the flawed (B-C) polar axis is not parallel to the correct hour line. If I > rotate the style about point A so that point B is at the dial's center, then > the polar axis shadow looks right. > > To test this, using Shadows 1.6.4, try drawing a due northwest vertical wall > dial (wall azimuth: 45 deg., inclination: 90 deg.) for Greenwich Great > Britain (lat: 51* 30', long: 0*) the perpendicular style. The B-C segment is > called the polar style. Note the weird position of the line A-B on the dial > face. I just can't figure it out. Am I doing something wrong or not > understanding something? > > Thanks > > John > > > - > -
Re: CardinalDirections, New Version
Hi Bill, The program runs well and the addition of showing the EoT and decl of the sun is appreciated. Please still correct the names for the time zones. In the list you write: GMT 0hrs Eastern European time, Greenwich GMT +2hrs Western European Time This should be: GMT 0hrs Western European time, Greenwich GMT +2hrs Eastern European Time Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: <[EMAIL PROTECTED]> To: Sent: Friday, August 29, 2003 6:43 PM Subject: CardinalDirections, New Version > I have tried to incorporate the suggestions so far received. I think I have > fixed the font problem, so it should display fine, I hope. I added EoT and > Declination data, and found and fixed a small mathematical error. I have not > added any time zones that are offset by 30 minutes, but maybe someday... > > The new version is now on my website, at > www.precisionsundials.com/software.htm > > -Bill > - > -
Re: Cardinal Direction Software
Hi Bill, Nice program and useful for diallists. Thanks for sharing this with us. Couldn't you give an output for the EoT and the sun's declination too? That also would be helpful. Is the atmospheric refration incorpurated in the calculations? Not of importance for the sun due south or north but it is for the sun east or west. In the list of the time zones you write: GMT 0hrs Eastern European time, Greenwich GMT +2hrs Western European Time Eastern and Western should be reversed. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: <[EMAIL PROTECTED]> To: Sent: Thursday, August 28, 2003 7:15 PM Subject: Cardinal Direction Software > I just finished writing a tidy little program that calculates when the sun is > exactly south (or north), east and west for any given date and location. I > wrote it to help mark a cardinal direction for laying out analemmatic dials, > but it can help orient any sundial. Using the vertical string method, an east > west line is much easier to mark than a north south one, because the sun is > lower and so the shadow stays sharp over a longer length. > > Of course, an east west shadow can occur only in the summer half of the year > for people outside the tropic zones (most of the folks on this list). For > people within the tropic zones, the an east west shadow will not form near the > summer solstice either. And for the unfortunate sundialist who lives on the > equator, an east/west shadow can occur on only 2 days of the year--the equinoxes. > > Download CardinalDirections.exe from www.precisionsundials.com/software.htm, > and let me know what you think. > > -Bill Gottesman > - > -
Re: Mystery Dial
Hi John, As Hans Behrendt writes in Schriften der Freunde alter Uhren, 1990, this dial is at Berkeley Castle, Gloucestershire. A black and white photo is in his article. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: John Carmichael To: M Stanier Cc: Sundial List Sent: Tuesday, August 19, 2003 6:04 PM Subject: Mystery Dial Hi Margaret (& others): This sundial appears in the wonderful Clocks Magazine SGS article, April 1988 that you sent me. But I do not have the text for this article; I only have the photos. I was wondering if there is any text in the article that describes this dial? Is there any other interesting text in the article that is missing from the website that you think would we should include? (Chris Daniel has given us permission to use photos and info from the article, but he's hard to reach, so I thought I'd ask you and the List). Thanks, John
Fw: Double glazing dial
To All interested in glass sundials and the refraction problem. Some one year ago I answered to Mike Shaw with a procedure to calculate a double glass sundial. This message I forward to the mailing list again. Playing with the factors for the pin-gnomon and the thickness of the glass panes shows the effect of the refraction. It depends strongly on the thickness of glass in the total thickness. If you have Deltacad I can send a macro which calculates these double glass dials and shows the pattern on screen. Hourlines and datelines for a zodiacal calendar are shown as well as the horizon line. The pattern is drawn in two layers, a non-refracted sundial and a refracted sundial. Switch between the two layers to see them separate. You need to change the values for the glass and the gnomon in the macro yourself. Send an e-mail if you want the macro to mailto:[EMAIL PROTECTED] Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "fer j. de vries" <[EMAIL PROTECTED]> To: "sundial" Sent: Monday, July 29, 2002 5:01 PM Subject: Re: Double glazing dial > Hello Mike, > > Nice idea to make a double glazing sundial. > I dont know of any program to do the job for you but here you will find a > solution to calculates such a dial. > The window can have any declination or inclination as you want. > > At my web site ( address below ) you may find a method to compute flat > sundials. > ( See the link at the site ) > We need the main procedure of that method with some extra routines to solve > the problem. > For definitions and details look at my site. > > I suggest to place the shadow casting point at some distance from the > outside pane to get a larger dial on your inside pane. > That distance I call g1 > If you don't want to do this just take g1 = 0 > > The thickness of the outside pane is g2 > The space between the two panes is g3 > The thickness of the inside pane is g4 > > I assume: > - the refraction index of glass is ref and equal for both panes. > - the medium between the two panes acts like air with no extra refraction. > - the panes are parallel. > > Of course you have to declaire values for latitude phi and for the dial's > inclination and declination i and d. > > Because (nearly) all the lines on the sundial will become curved, you need > to calculate a series of points ( decl, t ) for each line. > decl is the sun's declination > t is the hourangle of the wanted point. > > For each pointdecl, tdo as is written below. > > In decl, t > > x0 = sin t . cos decl > y0 = cos t . cos decl > z0 = sin decl > > R = 90 - phi > x1 = x0 > y1 = y0 . cos R - z0 . sin R > z1 = y0 . sin R + z0 . cos R > if z1 < 0 point isn't real: sun is beneath the horizon. > > R = d > x2 = x1 . cos R - y1 . sin R > y2 = x1 . sin R + y1 . cos R > z2 = z1 > > R = i > x3 = x2 > y3 = y2 . cos R - z2 . sin R > z3 = y2 . sin R + z2 . cos R > if z3 <= 0 point isn't real: sun isn't above the dial. > These are the coordiantes of the sun relative to the window. > > Add new routine > x4 = x3 / ref > y4 = y3 / ref > z4 = sqrt( 1 - x*x - y*y ) ( square root out of (...) ) > These are the coordinates of the sun corrected with the refraction index > ref. > > Now we have to calculate the shadowpoints on 4 sundials > xa = x3 . g1 / z3 > ya = y3 . g1 / z3 > > xb = x4 . g2 / z4 > yb = y4 . g2 / z4 > > xc = x3 . g3 / z3 > yc = y3 . g3 / z3 > > xd = x4 . g4 / z4 > yd = y4 . g4 / z4 > > The final coordinates of the point are > x = -( xa + xb + xc + xd ) > y = ya + yb + yc + yd > > The x value gets a minus sign because you will draw the pattern from the > opposite side as the gomon is. > > Use the two tests inside the procedure to exclude irrelevant points. > Also exclude points that are very far away of your sundial. > > Show us what your final dial will be. > > Best wishes, Fer. > > Fer J. de Vries > mailto:[EMAIL PROTECTED] > http://www.iae.nl/users/ferdv/ > Eindhoven, Netherlands > lat. 51:30 N long. 5:30 E > > - Original Message - > From: "The Shaws" <[EMAIL PROTECTED]> > To: "Sundial list" > Sent: Sunday, July 28, 2002 8:53 PM > Subject: Double glazing dial > > > > I have wondered for a while if it was possible to make use of the two > panes > > of glass in double glazed units to make a window sundial. > > > > To try out the concept, I made a prototype d
Re: Fw: Glass patterns
Tony, And a third life as sculptor and a fourth as architect and . John, Can't you make sites to encourage these professional too? Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: <[EMAIL PROTECTED]> To: "Sundial Mail List" Sent: Thursday, August 07, 2003 12:18 PM Subject: Re: Fw: Glass patterns > John Carmichael wrote: > > > >I can't get that one to work either, but try http://www.dfly.com/ > > > What a feast for the eyes! > > Now all I need is another life so that I can experiment with this > glorious medium too. > > Tony Moss. > - > -
Re: Can you help me?
Dear All, Another calendar converter I once dowloaded and now I placed it for download at http://www.de-zonnewijzerkring.nl/downloads/calendar-converter.zip Unzip the file with the option "use folder names". Start the .htm document calendar converter .htm It will work off line. The file to download will be removed after some weeks. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Piero Ranfagni" <[EMAIL PROTECTED]> To: Sent: Wednesday, July 30, 2003 6:24 PM Subject: Can you help me? > > Dear all, > > I need your help: > > For a Public Conference I'm preparing, I'm looking for javascript applet > about calendrical conversion that shows continously current date in > different date systems (gregorian julian, islamic, maya). Something > similar to http://www.relojesdesol.org/UbiSolENG.html I appreciate a lot. > During the conference I can't connect to net, so I prefer an applet to > download and run on my local machine, acknoledging all credits. > > Thank you in advance. > > Piero Ranfagni > > > * Piero Ranfagni * > * office Tel +39 055 2752 308 * > * fax +39 055 2752 292 > * cel.3291868081 > *e-mail [EMAIL PROTECTED] * > * www www.arcetri.astro.it/Italiano/EduPage * > * * > * Home Tel +39 055 487209 * > * Tel +39 0588 23037 * > > > > > - > -
Re: Best Latitudes for Sundials
Hello Hal, I would be pleased to have a copy of your book. How many dollar I have to send to you? I send the money by post, because by bank too many is asked by them. What is your postal address? Mine is Van Gorkumlaan 39 5641 WN Eindhovwen Netherlands. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: [EMAIL PROTECTED] To: sundial@rrz.uni-koeln.de Cc: [EMAIL PROTECTED] Sent: Wednesday, July 23, 2003 6:18 PM Subject: Best Latitudes for Sundials 7-23-03One source for latitude information is a book I recently published on sundial design now in its second printing. It uses matrix analysis applied to many planar sundials. Many of the examples show graphically the effects of latitude on sundial design characteristics.Hal Brandmaier
Re: The sundials of Rafael Soler
Anselmo, Beautiful pages. Thanks for distributing this. Fere. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Anselmo Pérez Serrada" <[EMAIL PROTECTED]> To: Sent: Tuesday, July 22, 2003 12:13 AM Subject: The sundials of Rafael Soler > Dear dialists, > > Little by little our web becomes less uncomplete. This time I have > included a new page dealing about our most outstanding gnomonist, > Dr. Rafael Soler Gaya. You can have a look at it at > > http://www.relojesdesol.org/soler.html > > It is written in Spanish, but I hope it doesn't pose any problem, because > it is essentially a graphical web: just press the links or any image you're > interested in. > > It is still on a beta stage, so let me know your opinions before I send > it to our associates (and to Dr. Soler). > > Best regards, > > Anselmo Perez Serrada > www.relojesdesol.org > > - > -
Re: Best latitudes for sundials?
Hi Art, Isn't it the contrary? I thought we at Northern latitude were the lucky ones to have more summer then winter time. As I read in Henry Michel, Traité de l'Astrolabe: La somme des jours du Printemps et de l'Été est actuellement de 186.46 jours tandis que la somme des jours de l'Automne et de l'Hiver est de 178.79 jours. Or may I conclude that you live at Southern latitude where people name our summer winter? Best wishes, Fer. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: [EMAIL PROTECTED] To: sundial@rrz.uni-koeln.de Sent: Monday, July 21, 2003 8:10 PM Subject: Re: Best latitudes for sundials? In einer eMail vom 17.7.2003 20:27:10 Westeuropäische Sommerzeit schreibt [EMAIL PROTECTED]: > As for latitude, isn't it true that everywhere on earth gets an average of> 12 hours of daylight over a year?No that's NOT true! What does "everywhere" mean? If "everywhere" includesthe the dial face of a north wall dial, then it's not true. If you mean the"flat" saurfacew of the earth, then you are correct.I hate to be pedantic, but (Well, actually, if the truth be told, I *love* to be pedantic.) this is not exactly true. Since fall and winter are together a few days longer than spring and summer (since the Earth is closest to the sun and moves fastest in its orbit in January), the North Pole, for example, gets less sunshine over the year than the South Pole.Art Carlson
Re: A "universal" vertical garden sundial
Chris, This sounds like a latitude independent sundial. Such a dial could be based on the formula: sin t = cos h sin az / cos delta t = hourangle h = altitude of the sun az = azimuth of the sun delta = sun's declination. No latitude in this formula. I know of some dials based on this formula: Freeman De Rijk Thijs de Vries Vinck Hidalgo + Valdes And based on ptolemaic coordinates solutions by Sawyer. Is your solution based on the same formula? In any case I am very curious about your sundial. Please let us know about it. Happy dialing, Fer. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: Chris Lusby Taylor To: sundial@rrz.uni-koeln.de Sent: Sunday, July 20, 2003 12:33 AM Subject: Re: A "universal" vertical garden sundial Hi All, There is such a thing as a universal vertical dial. I showed a prototype at the BSS Conference in York. I am working on a more attractive realisation in brass. It is truly universal and can be fixed flat on any wall. The wall doesn't need to be south-facing or even vertical. It could as well be horizontal. The gnomon angle does need adjusting by having a hinge at the point where it touches the dial plate, so that it points to the Pole Star. The dial engraving does not need any adjustment for different latitudes, orientations or declinations of wall. Further, the dial plate may be rotated to correct for EoT, or even summer time / daylight saving time, without introducing any inaccuracy. Too good to be true? I hope to prove that it is not. Chris Lusby Taylor Newbury, England 51.4N 1.3W - Original Message - From: Roger Bailey To: sundial@rrz.uni-koeln.de Sent: Friday, July 18, 2003 2:25 AM Subject: RE: A "universal" vertical garden sundial Hi Jim and all, You are right in thinking there is no such thing as a universal vertical dial. The gnomon angle and the hour angles on the dial face are specific functions of latitude. The real question is what contributes the greatest error, the hour angle on the dial plate or the gnomon angle. I am preparing an analysis on this question for a presentation at the upcoming NASS conference in Banff. This "Error Analysis of Garden Variety Sundials " will show the magnitude of the error for a sundial at the wrong latitude and evaluate partial compensation by changing the gnomon angle. The results for a dial designed for 43 degrees latitude used at 51 degrees latitude shows a maximum error of up to an hour. Changing the gnomon angle can reduces this to less than 20 minutes maximum. This is useful but tilting both the gnomon and plate can totally eliminate the error. The error is a function of the hour, the declination and the latitude difference. The full analysis will be available at and after the conference and probably published in the compendium. Roger Bailey Walking Shadow Designs N 51 W 115 -Original Message-From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]On Behalf Of J.TallmanSent: July 17, 2003 12:01 PMTo: Sundial ListSubject: A "universal" vertical garden sundial Hello All, Today I saw a vertical wall dial with an adjustable gnomon/style that has a hinge at the point where it connects with the dialplate. The dial is a south facing model and 12 noon is directly on the centerline of the dial and the gnomon. Obviously longitude and EoT correction would have to be compensated for when reading this dial. No declination lines appear on the dial face, just the familiar radiating hourlines of a south facing vertical sundial. Is this a junk dial? Assuming the hourlines were properly laid out for whatever latitude they were figured for, will it work for other users who mount it properly and set the gnomon to the appropriate angle for their latitude? Is a "universal" vertical dial even possible? Best Wishes, Jim Tallman
Re: New Sundial in Maryland
John, Congratulations with the botanical sundial. The combination with flowers is lovely. Fer. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: John Carmichael To: Sundial List Sent: Saturday, July 19, 2003 11:41 PM Subject: New Sundial in Maryland Hello all: Last week, the Brookside Botanical Gardens in Wheaton Maryland finished installing a monumental living plant sundial that I co-designed with Head Groundskeeper, Roger Haynes. Bob Terwilliger was kind enough to put it in the NASS Sundial Register at www.sundials.org/registry/ There's a photo there too. Wheaton #503 (Updated 07-03) Location: Brookside Botanical Gardens 1800 Glenallan Ave, near the butterfly house Remarks: A 20 foot diameter horizontal dial in the middle of a brick patio. The gnomon is 10' long, 8' tall and 12" wide, made of thin metal painted a verdant green. The dial itself is a bed of flowers, even the hour lines are small plants. Arabic numerals from 6am to 6pm. The flowers are changed seasonally for a gardener's delight. [Photo] John John L. Carmichael Jr.Sundial Sculptures925 E. Foothills Dr.Tucson Arizona 85718USA Tel: 520-696-1709Email: [EMAIL PROTECTED]Website: <http://www.sundialsculptures.com> Stained Glass Sundials of the World: http://advanceassociates.com/Sundials/Stained_Glass/
Re: Sundial Efficiency Rating
John, No doubt it could be of some benefit in the business of solar energy panels. However, I think professionals will know about ER as Energy Rating. I don't know if this is the same as the Efficiency Rating for Sunlight on a plane as we talk about it. Is there a professional in solar panels that reads this list?. Perhaps he or she could give a better answer how they calculate the best position for a panel at a given latitude. Best, Fer. PS The stained glass sundial page is nice to look at. Do you see the flies on some dials? Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "John Carmichael" <[EMAIL PROTECTED]> To: Sent: Sunday, July 20, 2003 5:10 AM Subject: Re: Sundial Efficiency Rating > Fer, this is my last question on the Efficiency Rating of solar illumination > idea. > > If you don't think a sundial's ER is a very useful concept in dialing, do > you think would it be a useful tool for designers and installers of solar > energy panels? > > John > > John L. Carmichael Jr. > Sundial Sculptures > 925 E. Foothills Dr. > Tucson Arizona 85718 > USA > > Tel: 520-696-1709 > Email: [EMAIL PROTECTED] > Website: <http://www.sundialsculptures.com> -
Re: Sundial Efficiency Rating
John, You asked: "Do you think the concept of a sundial's Efficiency Rating is useful in dialing? Do you like the term? Does an equivalent term already exist?" Well, I think only for myself. I don't see any need to know the ER of a sundial. Most of the times I want a sundial at some spot, some wall, and only then I am interested in the limitations of the dial, what hourllines are to be drawn. Sometimes a dial with only a few hours is more worthful then a dial with the maxiumum of hours. So I guess that the surrounding and the available spot is of more importance where to place a dial then to place a dial with maximum sunshine near that spot. In a park or on a large square of course I would recommend a horizontal dial or a multifacet dial to catch all the possible sunshine. On the other hand, on a building a limited dial on a wall that's visible for many is more worthful then a dial on a wall with more hours of sunshine but that most of the people never will see. A dial on my neighbours house could be more worthful then a dial on my own house. Sitting in my room I see his dial for many hours but I don't see my own dial. Nevertheless, nice to think about the Efficiency Rating. I have no suggestion for another term, nor did I ever read about it in this way. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "John Carmichael" <[EMAIL PROTECTED]> To: Sent: Saturday, July 19, 2003 1:56 AM Subject: Re: Sundial Efficiency Rating > Hi Fer > > Thanks for pointing out some of the holes in my ER estimates. Especially how > ER values of horizontals drop as they get near the equator and become > polars. It's obvious now that you pointed it out. And your other examples of > equatorials and verticals were good too. I especially learned a lot from > your discussion of the importance of latitude and its effect on ER. > > Thanks Fer for that and for explaining how to use the data from your program > to calculate ER on spreadsheet. Still, it's a lot of work to do to write > down all 365 hrs. of sunlight values onto the spreadsheet. > > Do you think the concept of a sundial's Efficiency Rating is useful in > dialing? Do you like the term? Does an equivalent term already exist? > > Thanks > > John > > John L. Carmichael Jr. > Sundial Sculptures > 925 E. Foothills Dr. > Tucson Arizona 85718 > USA > > Tel: 520-696-1709 > Email: [EMAIL PROTECTED] > Website: <http://www.sundialsculptures.com> > - Original Message - > From: "fer j. de vries" <[EMAIL PROTECTED]> > To: > Sent: Friday, July 18, 2003 1:24 PM > Subject: Re: Sundial Efficiency Rating > > > > John, > > > > At first let's split the problem into two. > > > > 1. What is the amount of sunshine on a plane in a year if 4380 hours = > half > > a year = 100%. > > 2. What else we have to take into account. > > > > Example: > > The horizontal dial. > > All latitudes ER = 100% > > Correct for statement 1 but for statement 2 remember that a horizontal > dial > > at > > latitude 0 is the same as a polar dial and we will miss some of the early > > and late hours and ER will decrease. > > This is because the pole style doesn't intersect the plane. > > That's why you say for an east or west dial 40%. > > > > So at first let's forget statement 2 and only look for statement 1, > > the amount of sunshine on a plane. > > > > I only think for northern latitude but for southern latitude the answers > are > > in priciple the same. > > > > Horizontal dial all latitudes: ER = 100%. > > > > Analemmatic dials, if horizontal: ER = 100%. > > (On any plane you could make an analemmatic dial so I add "if > horizontal". ) > > > > Equatorial dials: depend on the latitude > > - at the poles this is a horizontal dial so ER = 100% > > - at latitude 0 this is a vertical north facing dial so ER = 50% > > - other latitudes from 50% to 100% > > - the other side of the equatorial dial: ER = 100%-value above > > > > Vertical south facing dials: depend on the latitude > > - at the poles ER = 50% > > - at latitude 0 ER = 50% > > - at latitude 45 ER is maximim and about 80%? > > - other latitudes 50% to 80% > > > > North facing dial: depend on latitude > > - ER = 100%-value for south facing dial > > > > East and west facing dials > > - east facing dial: ER = 50%
Re: Sundial Efficiency Rating
John, At first let's split the problem into two. 1. What is the amount of sunshine on a plane in a year if 4380 hours = half a year = 100%. 2. What else we have to take into account. Example: The horizontal dial. All latitudes ER = 100% Correct for statement 1 but for statement 2 remember that a horizontal dial at latitude 0 is the same as a polar dial and we will miss some of the early and late hours and ER will decrease. This is because the pole style doesn't intersect the plane. That's why you say for an east or west dial 40%. So at first let's forget statement 2 and only look for statement 1, the amount of sunshine on a plane. I only think for northern latitude but for southern latitude the answers are in priciple the same. Horizontal dial all latitudes: ER = 100%. Analemmatic dials, if horizontal: ER = 100%. (On any plane you could make an analemmatic dial so I add "if horizontal". ) Equatorial dials: depend on the latitude - at the poles this is a horizontal dial so ER = 100% - at latitude 0 this is a vertical north facing dial so ER = 50% - other latitudes from 50% to 100% - the other side of the equatorial dial: ER = 100%-value above Vertical south facing dials: depend on the latitude - at the poles ER = 50% - at latitude 0 ER = 50% - at latitude 45 ER is maximim and about 80%? - other latitudes 50% to 80% North facing dial: depend on latitude - ER = 100%-value for south facing dial East and west facing dials - east facing dial: ER = 50% - west facing dial: ER = 50% Polar dials: depend on the latitude - at the poles ER = 50% - at latitude 0 this is a horizontal dial: ER = 100% - other latitudes ER from 50% to 100% - the other side of the polar dial: ER = 100%-value above The ER for inclining-declining dials is too complex to me to give an overview as for the most common dials. I hope I didn't make mistakes in my list. If so, please send corrections. Happy dialing, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "John Carmichael" <[EMAIL PROTECTED]> To: Sent: Friday, July 18, 2003 4:50 PM Subject: Re: Sundial Efficiency Rating > Hi Fer > > Thank God for proofreaders! Must have pushed wrong button on my calculator. > Yep, a sundial with a 100% Efficiency Rating would receive 4380 hours of > sunlight in a year. > > Fer, without doing all the math to give exact values, what ER values do you > think the major sundial types have? > > These are my "feelings" or speculations on relative ER values of the major > sundial types. (Some types though will have a range of ER values for > different latitudes though, so let's call this average ER values of a type: > > Horizontals, all latitudes: ER=100% > Analemmatics, all latitudes: ER= 100% > equatorials, all latitudes: ER= 80 % (?I'm guessing) > polars, all latitudes: ER = variable depending on time span of face, usually > about 75% > south vertical walls, N. Hemis: ER= 80% (? I'm guessing) > East Vertical walls, 40% (I'm really guessing!) > West Veritical walls, 40% > North Walls, N. Hemis: 20%(I'm really really guessing!) > > How important do you think latitude is in affecting ER values in declining > and inclining dials Fer? > > > John > > John L. Carmichael Jr. > Sundial Sculptures > 925 E. Foothills Dr. > Tucson Arizona 85718 > USA > > Tel: 520-696-1709 > Email: [EMAIL PROTECTED] > Website: <http://www.sundialsculptures.com> > - Original Message - > From: "fer j. de vries" <[EMAIL PROTECTED]> > To: "sundial" > Sent: Friday, July 18, 2003 4:51 AM > Subject: Re: Sundial Efficiency Rating > > > > John, > > > > How long a year is in America > > We have about 365 days of 24 hours that gives 8760 hours a year. > > The sun will shine on any horizontal plane the half of this, that's 4380 > > hours a year. > > But you have 12,365 sunshine hours a year.. > > How lucky you are to have about three times more time then we have. > > > > Indeed, for any plane you have to calculate the amount of sun it will > catch. > > My graph shows that for any plane at any latitude. > > The area of the light zone could be measured and the total area of the > graph > > is 8760 hours. > > This gives an idea of the efficiency rate for any plane. > > > > Fred Sawyer once published formulas for the hours of sunshine for any > plane. > > Compendium vol. 1 nr. 4 and an addition in Compendium vol. 2 nr. 1. > > > > Put them in a spreadsheet or other program to ca
Re: Sundial Efficiency Rating
John, How long a year is in America We have about 365 days of 24 hours that gives 8760 hours a year. The sun will shine on any horizontal plane the half of this, that's 4380 hours a year. But you have 12,365 sunshine hours a year.. How lucky you are to have about three times more time then we have. Indeed, for any plane you have to calculate the amount of sun it will catch. My graph shows that for any plane at any latitude. The area of the light zone could be measured and the total area of the graph is 8760 hours. This gives an idea of the efficiency rate for any plane. Fred Sawyer once published formulas for the hours of sunshine for any plane. Compendium vol. 1 nr. 4 and an addition in Compendium vol. 2 nr. 1. Put them in a spreadsheet or other program to calculate this for 365 days, sum the answers and you have the hours of sunshine for whole the year. Best wishes and many sunshine, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "John Carmichael" <[EMAIL PROTECTED]> To: Sent: Thursday, July 17, 2003 10:43 PM Subject: Re: Sundial Efficiency Rating > Hi Jim: > > Yes Fer's Program and other programs will tell you the amount of sunshine > that any > > particular site will receive, but that's only gives part of the answer > because it gives hours of sunshine at the site and not on the dial face. > (You're talking about Site Efficiency, not Sundial Efficiency) No, such a > computer program would have to be more like Bob Hough's program that is dial > specific as well as site specific. But Bob's program only gives part of the > answer too. > > To determine the Efficiency Rating of a particular dial, you would have to > calculate the # of hours that the sun shines on its face for each day of the > year, then you would have to add up all those hours. > > John > > - Original Message - > From: "J.Tallman" <[EMAIL PROTECTED]> > To: > Sent: Thursday, July 17, 2003 12:13 PM > Subject: Re: Sundial Efficiency Rating > > > > John, > > > > I think Fer's sundial program will tell you the amount of sunshine that > any > > particular site will receive, and I think it takes into account the > > different sundial types and declinations. It will give you the sunrise and > > sunset times as well. > > > > It now has an easier name to spell as well, it is called ZW2000 and can be > > had here: > > > > http://www.de-zonnewijzerkring.nl/eng/index-links.htm > > > > A version of the software is also on the NASS Repository disk. > > > > Hope this helps, at least you can experiment with it to get a feel for > some > > of the questions you asked. > > > > Jim > > > > > > - > > > > > - > -
Re: vertical wall dial latitudes?
Hi John, Fall and Spring, I didn't look very close to it but only to the fact that statement A is opposite to B and that sounds well to me. Sorry I was some lazy. A west or east dial have their gnomon parallel to the plane and all dials that decline some degrees from west or east have gnomons that don't intersect the vertical wall near the dial plate. But still these are practical dials to me. Otherwise many should be named "not practical". And I made another mistake. A polar dial in practice shows about 10 hours, not 12 as I wrote. Best, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "John Carmichael" <[EMAIL PROTECTED]> To: Sent: Tuesday, July 15, 2003 4:49 PM Subject: Re: vertical wall dial latitudes? > Hello Fer and others: > > Thanks for checking my concusions, but I think I made a mistake. Would you > look again closely at this statement I made. Now that I think about it I > think it is wrong because I got the seasons backwards; > > Here is the possibly flawed statement: > > 1. If a vertical wall sundial is on the equator and > > > A) If it is on a southern wall, it will function from spring equinox till > > fall equinox and will be shaded by the building from fall equinox till > > spring equinox. > > > B) If it is on a northern wall, it will function from to fall equinox till > > spring equinox and will be shaded by the building from spring equinox to > > Fall equinox. > > Think about it, shouldn't it be this: > 1. If a vertical wall sundial is on the equator and > > A) If it is on a southern wall, it will function from fall equinox till > spring equinox and will be shaded by the building from spring equinox till > fall equinox. > > B) If it is on a northern wall, it will function from to spring equinox till > fall equinox and will be shaded by the building from fall equinox to > spring equinox. > > Thanks > > ps. I still have some doubts about the praticality of constructing vertical > wall dials in polar latitudes, because the gnomon would have to be almost > parallel to the dial face. But I guess that that's ok, it just wouldn't be > a typical gnomon design with a simple rod protruding from the dial center. > Any thoughts on this. > > John > > John L. Carmichael Jr. > Sundial Sculptures > 925 E. Foothills Dr. > Tucson Arizona 85718 > USA > > Tel: 520-696-1709 > Email: [EMAIL PROTECTED] > Website: <http://www.sundialsculptures.com> > - Original Message - > From: "John Carmichael" <[EMAIL PROTECTED]> > To: "Sundial List" > Sent: Monday, July 14, 2003 1:26 PM > Subject: vertical wall dial latitudes? > > > > Hello All, > > > > > > > > I've been wondering what latitude restrictions there are on vertical wall > > dials? > > > > > > > > I've thought about it and here are my conclusions. Are my conclusions > > correct? > > > > > > > > 1. If a vertical wall sundial is on the equator and > > > > > > > > A) If it is on a southern wall, it will function from spring equinox till > > fall equinox and will be shaded by the building from fall equinox till > > spring equinox. > > > > > > > > B) If it is on a northern wall, it will function from to fall equinox till > > spring equinox and will be shaded by the building from spring equinox to > > Fall equinox. > > > > > > > > 2. All due south vertical wall dials in the tropics of the northern > > hemisphere will be completely shaded all day for part of the summer. > > > > > > > > 3. All due north vertical wall dials in the tropics of the southern > > hemisphere will be completely shaded all day for part of the winter. > > > > > > > > 4. Vertical wall dials are impractical at polar latitudes above 66 > degrees. > > > > > > > > 5. Vertical wall dials are impossible at the poles. > > > > > > > > > > > > Thanks, > > > > > > > > John > > > > > > John L. Carmichael Jr. > > Sundial Sculptures > > 925 E. Foothills Dr. > > Tucson Arizona 85718 > > USA > > > > Tel: 520-696-1709 > > Email: [EMAIL PROTECTED] > > Website: <http://www.sundialsculptures.com> > > > > > > - > > > > > - > -
Re: Stained Glass Sundial Photos
Anselmo, Make gif files of the drawings for the Internet. The files don't need many kB's. Select the drawing and copy it to clipboard. Input it in a program like Paintshop and save it as .gif file. You also could make them with a capture procedure of many drawing programs. Best, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Anselmo Pérez Serrada" <[EMAIL PROTECTED]> To: Sent: Tuesday, July 15, 2003 10:13 AM Subject: Re: Stained Glass Sundial Photos > > Dear all, > > I would like to draw your attention on Fabio's web on a new kind of > Stained Glass > Sundials. They are very smart, elegant and full of new possibilities. > Maybe there should > be a link to his web in the 'official' web. > > Oh, by the way, I survived to the 'Gnomonics Course for Children' :-) > !! I'll tell you > later on how it went and I'll try to place some photos in our web... > Does anybody > know which is the best format file to convert DeltaCad drawings to place > them in > a web? Or perhaps is it preferably to place them as 'downloads'? > > Best regards, > > Anselmo Perez Serrada > : : : : : : : : : : : : : : : : : : : : : : : : : > [EMAIL PROTECTED] > > >hola Anselmo, > > > >today I've published on my web-site some news and pictures about the > >negative bifilar sundials. > > > >The address is http://www.nonvedolora.it/english/experiment2.htm > > > >ciao Fabio Savian > > > > > >- Original Message - > >From: "Anselmo Pérez Serrada" <[EMAIL PROTECTED]> > >To: > >Sent: Friday, July 04, 2003 11:24 PM > >Subject: Re: Stained Glass Sundial Photos > > > > > > > > > >>Fabio Savian wrote: > >> > >> > >> > >>>I think there is another option. > >>> > >>>You can built a bifilar sundial with a negative thread. > >>>The negative thread is behind the dial so that it is inside and may be > >>>drawen on the wall or on the floor. The outside thread casts a shadow > >>>through the stained glass and the shadow will cross the negative thread > >>> > >>> > >in a > > > > > >>>point : the knot. The stained glass will be casted too and the hour will > >>> > >>> > >be > > > > > >>>shown by the knot on this projected dial. > >>>The negative thread may be hanging too, in this case the knot will be the > >>>cross of the shadows of the 2 threads. > >>>With these bifilar dials the stained glass may correspond to a dial with > >>> > >>> > >a > > > > > >>>different declination regards to the wall or may be like an equinoctial > >>>dial. > >>>The bifilar dial may also have both the threads negative. > >>>I have drawen some of these bifilar dials last year on the italian > >>>mail-list. If someone is interested on them I can put the pictures on my > >>>website or send them by e-mail. > >>>I have no news about bifilar realized with negative thread. > >>> > >>>ciao Fabio Savian > >>> > >>>- > >>> > >>> > >>> > >>> > >>Please, Fabio, place them on your (excellent) web! I am sure I am not > >>the only one interested in them! > >> > >>Anselmo > >> > >> > >> > >>- > >> > >> > > > >- > > > > > > > > > > > - > -
Re: vertical wall dial latitudes?
Hi John, Your conclusions 1 to 3 are true but I disagree with 4 and 5. A vertical dial at the poles is usefull as many other polar dial. (as long as you define one meridian as the standard meridian). You could make one for your latitude too. It has the same restrictions, it operates for about 5 - 17 = 12 hours. A northern dial at your latitude will operate less hours. In general: any plane that catches a glimpse of the sun is worth to be used as a sundial. Best, Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "John Carmichael" <[EMAIL PROTECTED]> To: "Sundial List" Sent: Monday, July 14, 2003 10:26 PM Subject: vertical wall dial latitudes? > Hello All, > > > > I've been wondering what latitude restrictions there are on vertical wall > dials? > > > > I've thought about it and here are my conclusions. Are my conclusions > correct? > > > > 1. If a vertical wall sundial is on the equator and > > > > A) If it is on a southern wall, it will function from spring equinox till > fall equinox and will be shaded by the building from fall equinox till > spring equinox. > > > > B) If it is on a northern wall, it will function from to fall equinox till > spring equinox and will be shaded by the building from spring equinox to > Fall equinox. > > > > 2. All due south vertical wall dials in the tropics of the northern > hemisphere will be completely shaded all day for part of the summer. > > > > 3. All due north vertical wall dials in the tropics of the southern > hemisphere will be completely shaded all day for part of the winter. > > > > 4. Vertical wall dials are impractical at polar latitudes above 66 degrees. > > > > 5. Vertical wall dials are impossible at the poles. > > > > > > Thanks, > > > > John > > > John L. Carmichael Jr. > Sundial Sculptures > 925 E. Foothills Dr. > Tucson Arizona 85718 > USA > > Tel: 520-696-1709 > Email: [EMAIL PROTECTED] > Website: <http://www.sundialsculptures.com> > > > - > -
Re: Your Opinion?
Hi John, That's too dark. It makes me depressive. Best, Fer. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: John Carmichael To: Sundial List Sent: Friday, July 11, 2003 6:01 PM Subject: Your Opinion? Hi guys, Do you like this better than the white background? We're interested in hearing someone else's opinion. see temp site: http://advanceassociates.com/Sundials/Stained_Glass/index1.html John John L. Carmichael Jr.Sundial Sculptures925 E. Foothills Dr.Tucson Arizona 85718USA Tel: 520-696-1709Email: [EMAIL PROTECTED]Website: <http://www.sundialsculptures.com>
Re: Emailing: vagnozzi1.jpg
Rick, Look at my homepage for - Links-Downloads There you will find programs to download as ZW2000 Sonne Sahdows. Good luck eith your dial. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: Rick Mintz To: sundial@rrz.uni-koeln.de Sent: Monday, July 07, 2003 9:09 PM Subject: Emailing: vagnozzi1.jpg Good morning, I am looking for information that will allow me to construct a sundial as in the attached photograph. I found the image at http://web.fc-net.fr/frb/sundials/gb/defaut.htm . Anyone have guidance as to how to duplicate this design? Thanks! Rick
The fly on Styained Glass Sundials
Rereading the stuff I found I see Hans Behrendt also published about these dials in: Schriften der Freunde alter Uhren, Band XIX, 1980 (German) There are 14 non UK dials and 4 UK dials described. Photo's in black & white. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E -
The fly on Stained Glass Sundials
Patrick and other readers interested in flies, In my mind I still had the idea that more flies fly around in the UK on glass sundials than only five. So I tried to find what is in my study about these intriguing flying objects. I happen to have a home-video of late Hans Behrendt, Germany, about glass sundials and I could find it back and it still works. The video is made in 1989 and 1990 of a series of dia's. The first part shows: 7 dials in Germany 6 in Switzerland 1 in Austria 1 in Poland. On the dial from Austria, dated 1550, a fly is seen. The second part of the video shows 47 English dials and on 21 dials a fly is seen. So it was rather common in England to incorporate a fly. One of the dials has a spider as well and another one only has a spider on it. Most of the English dials are before 1700 and the oldest is dated 1585. I also found some literature about these glass dials. Hans Behrendt, Alte Englische Fenstersonnenuhren, Schriften der Freunde alter Uhren, Band XXIII, 1984 (German) Hans Behrendt, Alte Englische Fenstersonnenuhren (II), Schriften der Freunde alter Uhren, Band XXIX, 1990 (German) and he also mentions Christofer Daniel, Stained-glass window sundials, Country Life Magazine, London, 26/2/87. Christofer Daniel, Stained-glass window sundials in England and Wales, Clocks april 1988 I have no acces to what Daniel wrote but I am interested. So we have some to read and perhaps the video of Behrendt is in the arhives of BSS as well. Behrendt writes about a reason the fly was on the dial. But it is too dificult for me to translate the German in readable English. I can send the German text to someone who is willing to translate the German into English. In any case it has to do with the fly that carries diseases that shortens lifetime what was feared by the people and so it has a connection with the flying (life)time. Behrendt also mentions how the fly has to be drawn. The body and wings are on the inside of the pane, the side you look at. The legs ( do you name them legs?) are drawn on the outside. This should give a kind of 3D view. Another characteristic feature is a cross at noon in stead of a number XII and on many dials an hourglass is drawn. Well, these are some historical facts I wanted to tell and perhaps it is worth to keep them in mind if more such dials would be constructed. Best wishes to all, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Patrick Powers" <[EMAIL PROTECTED]> To: Sent: Thursday, July 03, 2003 12:24 AM Subject: Stained Glass Sundials > Message text written by INTERNET:sundial@rrz.uni-koeln.de > > >Another question about these kind of dials. Shouldn't be there a fly on a > glass sundial? I think to know many English examples have a fly drawn on > it.< > > It's true that a few of the older UK stained glass dials have an image of a > fly - it's thought to be a pun on 'Time Flies' - but it is not universal. > Only about five such dials have this as far as I can see. They just happen > to be the more well known dials... > > Patrick. > > - > -
Stained Glass Sundials
John Carmichael asked for Glass Sundials in Europe other then in the UK. A famous one is in Ulm, Germany, in the east wall of the Rathaus. (City hall). I sent a copy of a picture to John. There are more as mentioned in the large book by Rohr, Die Sonnenuhr. Z¸rich Basel Stuttgart Innsbruck Baden. Another question about these kind of dials. Shouldn't be there a fly on a glass sundial? I think to know many English examples have a fly drawn on it. Best, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E -
Re: Stained Glass Sundial Photos
Hi John, You may find some in Compendium. vol. nr. date 4-1 march 1997 1-3 aug 1994 7-2 june 2000 2-1 march 1995 Best wishes, Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "John Carmichael" <[EMAIL PROTECTED]> To: "Sundial List" Sent: Monday, June 30, 2003 5:27 PM Subject: Stained Glass Sundial Photos > Hello all: > > I've been considering contacting local stained glass artisans to inform them > of the possibility of making stained glass sundials. I'm sure many of them > would be thrilled to find out that they can make working sundials and would > love to offer them to their clients. All they need is a little help from a > dialist to do the drawings. > > Since "a picture is worth a thousand words", I'd like to show them some > photographs of some of these dials, but I don't have any photos. > > Do any of you have any photos of stained glass sundials that you could share > with me? > > thanks so much, > > John > > John L. Carmichael Jr. > Sundial Sculptures > 925 E. Foothills Dr. > Tucson Arizona 85718 > USA > > Tel: 520-696-1709 > Email: [EMAIL PROTECTED] > Website: <http://www.sundialsculptures.com> > > > - > -
Re: Declination line precision over the years
Hi Jim, Declination lines will last for a very long time, at least if: - the dial was correct constructed - the orientation of the dial isn't changed in the course of ages - the dial isn't restored in a wrong way and so on. Date lines are more difficult. Except for the solstices a dateline is at least one time wrong in a year because it will be used two times with the sun's declination of the same value. In other words, for each date line two dates are true. For a certain date the sun's declination will change each year in a leap year period but also over a long period. So calculate for a date of your choice the sun's declination for e.g. 1600, 1700, . 2100 to see the change. It will depend on the date you have choosen. For a zodiacal calendar however, the lines wll last for a longer time. The zodiacal calendar isn't in phase with the real situation but with the longitude of the sun and by that with the sun's declination. In fact it are declination lines. Also you have to look to the change in the obliquity of the earth axis. Well, there are many aspects to think about but in dayly dialling we may forget a lot of them. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "J.Tallman" <[EMAIL PROTECTED]> To: Sent: Monday, June 16, 2003 9:34 PM Subject: Declination line precision over the years > Hello all, > > This recent discussion has me wondering about some of the old dials in > Europe, and the declination lines on some of them. How well has the > precision of these lines held up over time? > > Just for general discussion purposes, if I put a declination line for a > specific date on one of my sundials, how long could I expect it to be > accurate? > > > Best Wishes, > > Jim Tallman > > > - > -
Re: Precise EOT Program - Comments and a correction
Gianni, You wrote: > Because of these changes of the EOT from one year to the other it is wrong, > in my > opinion, to use values very precise in calculating sundials. They may be > useful to find the exact istant of the noon in a given day, etc. > I don't fully agree with your arguments. If drawing the EoT curves ( analemmas ) on a sundial try values with a reasonable high accuracy. But use the combination sun's declination and EoT. These combinations don't hardly change in a man's life. Also declination lines on a sundial are accurate for such a period and so far you may use the values of any year. I think that's even better then using average values for a leap year period. Problems occur if date lines are drawn. The relation between date on one hand and sun's declination / EoT on the other hand changes in the leap year period as you wrote. The result is that in fact date lines aren't precize on a dial but declination lines are. Declination marks on an EoT curve would be better then date marks for accuracy, however, many times I would prefer date marks or datelines. A dial isn't a precision instrument in most of the times. I fully agree with you writing:: They may be useful to find the exact instant of the noon in a given day. But than the correct values for the running year have to be used because you also use the date. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Gianni Ferrari" <[EMAIL PROTECTED]> To: "SUNDIAL MAILING LIST" Sent: Monday, June 16, 2003 6:44 PM Subject: Re: Precise EOT Program - Comments and a correction > > Hank, > > some years ago also I have obtained the Fourier approximation of the EOT > from its MEAN values on a 48 year period (from 2000 to 2047) ( I published > it in 2000) > > The coefficients that I have found are practically equal to those found by > you and precisely: > > t = 2 * pi * (j - 1) / 365.2421897 >EOT = 0 + > + 7.3656 * Cos(t + 1.5113) _ > + 9.9158 * Cos(2 * t + 1.9574) _ > + 0.3060 * Cos(3 * t + 1.8347) _ > + 0.2027 * Cos(4 * t + 2.3213)_ > > Where j = N-1 and N = number of the day in the year (32 for February the > 1st) > > I have also calculated the difference ( true exact value - mean value from > formula ) in every day of the perod (17532 days) and I have found a maximum > error less than 18 sec. > > The values (exact) of the EOT changes from one year to the other as in the > follwing example. > > EOT calculated on December 25 at noon in Greenwich : > > > DAYTime Eq. > > DEC 25 2003 Th- 6.90 sec > > DEC 25 2004 Sa+16.74 > > DEC 25 2005 Su+ 8.64 > > DEC 25 2006 Mo+ 1.68 > > DEC 25 2007 Tu- 5.82 > > DEC 25 2008 Th +15.72 > > DEC 25 2009 Fr + 9.00 > > DEC 25 2010 Sa+ 0.84 > > > The mean value = 6.54 sec. On December 26 the mean value = 36.2 sec > > Because of these changes of the EOT from one year to the other it is wrong, > in my > opinion, to use values very precise in calculating sundials. They may be > useful to find the exact istant of the noon in a given day, etc. > > A regard > > Gianni Ferrari > > > > P.S. - The EOT is non changed from the atmospheric refraction > > > > > > > > > > - > -
Re: Precise EOT Program
Hi John, The longest days are around Christmas. A day than is about 24 hours and 30 seconds. More precisely it is about 22/23 december. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "John Carmichael" <[EMAIL PROTECTED]> To: Sent: Friday, June 13, 2003 3:16 PM Subject: Re: Precise EOT Program > Hi everybody, > > Thanks to all who wrote. Looks like most people favor the Dialist Companion > for precise EOT values. > > I need precise EOT for setting my sundials and for precise time readings. I > got spoiled at Kitt Peak by Bob Hough's complete list of these EOT values. > I can see definite shadow movement in as little as 10 seconds on my large > cable dials and I know that EOT values can change more than that in just one > day. By the way, does anybody know what the maximum amount EOT changes in > 24 hours and on what date this occurs? > > John > > John L. Carmichael Jr. > Sundial Sculptures > 925 E. Foothills Dr. > Tucson Arizona 85718 > USA > > Tel: 520-696-1709 > Email: [EMAIL PROTECTED] > Website: <http://www.sundialsculptures.com> > - Original Message - > From: "fer j. de vries" <[EMAIL PROTECTED]> > To: > Sent: Friday, June 13, 2003 1:22 AM > Subject: Re: Precise EOT Program > > > > John, > > > > Even if you want a procedure to calculate the EoT at a certain time at a > > certain day, what accuracy do you need? > > If 5 seconds is enough you could use the year formula calculated by my > > program equadecl. > > Use as input a decimal daynumber to get the wanted EoT but also correct > for > > the longitude you are living. > > The basic output is for noon GMT. > > > > If you need higher precision then look for another procedure. > > > > I also would like to know for what reason you need such a procedure in > > dialing. > > > > Fer. > > > > > > Fer J. de Vries > > > > De Zonnewijzerkring > > mailto:[EMAIL PROTECTED] > > http://www.de-zonnewijzerkring.nl > > > > Home > > mailto:[EMAIL PROTECTED] > > http://www.iae.nl/users/ferdv/index-fer.htm > > Eindhoven, Netherlands > > lat. 51:30 N long. 5:30 E > > > > - Original Message - > > From: "John Carmichael" <[EMAIL PROTECTED]> > > To: "Sundial List" > > Sent: Thursday, June 12, 2003 11:14 PM > > Subject: Precise EOT Program > > > > > > > Hello all, > > > > > > I'm looking for a handy precise program that calculates EOT values in > > > minutes and seconds at particular times during the day. In other words, > I > > > don't want the average EOT value for the day as found in the printed > > tabular > > > EOT values in Mayall & Waugh. Instead, it would give the exact EOT > value > > at > > > a particular time during the day. > > > > > > I've found several EOT calculator programs (applets) on the "Current > Data" > > > link at sundials.org. Does anybody know if the values given in these > > applets > > > are daily averages or precise values? > > > > > > Thanks for any suggestions. > > > > > > John > > > > > > John L. Carmichael Jr. > > > Sundial Sculptures > > > 925 E. Foothills Dr. > > > Tucson Arizona 85718 > > > USA > > > > > > Tel: 520-696-1709 > > > Email: [EMAIL PROTECTED] > > > Website: <http://www.sundialsculptures.com> > > > > > > > > > - > > > > > > > - > > > > > - > -
Re: Precise EOT Program
John, Even if you want a procedure to calculate the EoT at a certain time at a certain day, what accuracy do you need? If 5 seconds is enough you could use the year formula calculated by my program equadecl. Use as input a decimal daynumber to get the wanted EoT but also correct for the longitude you are living. The basic output is for noon GMT. If you need higher precision then look for another procedure. I also would like to know for what reason you need such a procedure in dialing. Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "John Carmichael" <[EMAIL PROTECTED]> To: "Sundial List" Sent: Thursday, June 12, 2003 11:14 PM Subject: Precise EOT Program > Hello all, > > I'm looking for a handy precise program that calculates EOT values in > minutes and seconds at particular times during the day. In other words, I > don't want the average EOT value for the day as found in the printed tabular > EOT values in Mayall & Waugh. Instead, it would give the exact EOT value at > a particular time during the day. > > I've found several EOT calculator programs (applets) on the "Current Data" > link at sundials.org. Does anybody know if the values given in these applets > are daily averages or precise values? > > Thanks for any suggestions. > > John > > John L. Carmichael Jr. > Sundial Sculptures > 925 E. Foothills Dr. > Tucson Arizona 85718 > USA > > Tel: 520-696-1709 > Email: [EMAIL PROTECTED] > Website: <http://www.sundialsculptures.com> > > > - > -
Re: Dial calculation mystery
Hello John, Bruno Ernst is a pseudonym. De Rijk is his real name. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "John Gerard Malecki" <[EMAIL PROTECTED]> To: Sent: Sunday, June 08, 2003 11:06 PM Subject: Re: Dial calculation mystery > fer j. de vries wrote (2003-06-08T11:15:00+0200): > > > > The article is by Bruno Ernst = J.A.F. de Rijk. > > Hi Fer, > > Great article. Just out of word curiosity, what is the intended > meaning of the equal sign? On the web page you have > > Bruno Ernst ( = J.A.F. de Rijk ) > > Does this means that Bruno Ernst is a pseudonym for J.A.F. de Rijk or > vice versa? > > - > -
Re: Geometric dial layout
Dave, The final address then is: http://www.AdvanceAssociates.com/Sundials/GeomConst/ and that addres works well. I dont see picture #2, also not after reload, but it's not important to follow the construction. In the source code I read mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Dave Bell" <[EMAIL PROTECTED]> To: Sent: Sunday, June 08, 2003 5:09 PM Subject: Re: Geometric dial layout > D'oh!!! That's what comes of posting late at night. > Mac is correct, of course - I left off the top level domain, ".com"! > And, oddly enough, some browsers will fill in. > > As for Bobo's finding that image #2, "Adding horizontal construction > lines" is missing, it looks OK from here. Did anyone else miss it? It's > possible that that image simply didn't download (automatically) for > you. Try reloading/resfreshing the page. If that doesn't work, try > right-clicking on the placeholder and View Image. > > Dave > -
Re: Geometric dial layout
Dave, What is the correct address? I don't get at the page you mentioned. Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Dave Bell" <[EMAIL PROTECTED]> To: "Sundial List" Sent: Sunday, June 08, 2003 9:38 AM Subject: Geometric dial layout > I drew up some stages in the development of a horizontal dial, using > DeltaCad and the method described earlier. They are posted for reference > at: > > http://www.AdvanceAssociates/Sundials/GeomConst/ > > Dave > 37.28N 121.97W > > - > -
Re: Dial calculation mystery
Chris, John, Dave, Anselmo and others, I would like to add something to this discussion. All dials like the analematic dial, the Foster-Lambert dial and many more, including the usual horizontal dial are members of just one family: the eqatorial projection dials. Imagine an equatorial ring with hourpoints and a scale of date on the polestyle. Project this ring vertical onto the horizontal plane, from the zenith point, and you get the usual analemmatic sundial with an ellipse of which the long axis is east-west and in the center a scale of date. Project this ring in the direction of the polestyle onto the horizontal plane and you get the usual horizontal sundial with an ellipse of which the long axis is in the north-south direction as Chris noted. The scale of date now is just a point and therefore we can draw complete hourlines and not only hourpoints on the ellipse. An article about this you may read at the web site of De Zonnewijzerkring. Follow the links: Calculate and construct Analemmatic sundials-Equatorial projection dials. Article (in English) The article is by Bruno Ernst = J.A.F. de Rijk. I think this article is of great importance and a must for all gnomonists. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Chris Lusby Taylor" <[EMAIL PROTECTED]> To: ; "Anselmo Pérez Serrada" <[EMAIL PROTECTED]> Cc: Sent: Saturday, June 07, 2003 9:38 PM Subject: Re: Dial calculation mystery > > - Original Message - > From: "Dave Bell" <[EMAIL PROTECTED]> > To: "Anselmo Pérez Serrada" <[EMAIL PROTECTED]> > Cc: > Sent: Saturday, June 07, 2003 7:04 PM > Subject: Re: Dial calculation mystery > > > > On Sat, 7 Jun 2003, [ISO-8859-1] Anselmo Pérez Serrada wrote: > > > > > I think I can help you on this. They use a very elegant method to draw a > > > sundial based on geometrical > > > affinity that traces back to our High School days: > > > > > > 1. Draw two concentrical circles : one of radius r and the other one of > > > radius r*sin(Lat) > > > 2. Now draw a sheaf of 24 equispaced lines from its center as if it > > > were an equatorial dial. > > > 3. These lines intersect the circles at points I' and I'', II' and > > > II'', and so on up to XXIV' and XXIV''. > > > 4. Now trace horizontal lines from the inner points and vertical lines > > > from the outer points. Let's call > > > I the point where the lines from I' and I'' intersect, II the point for > > > II' and II'', and so on. > > > 5. If we connect these points we just have the analemmatic ellipse, > > > right? Well, but if we trace lines > > > from the center to these points we get a horizontal dial for that > > > latitude. Isn't that nice? > > > > Very well described, Anselmo! > > > > Everything agrees perfectly with the original article, except you have one > > circle of radius 1 and the other of 1*sin(lat). Now, if I am looking at > > this correctly, that would make the second circle smaller than the first > > (and also avoid the singularityat 0 degrees!) However, is the ratio of the > > two circles' size the same in both constructions? I'll have to draw them > > up, and scale one to match the other... > > > > Dave > > 37.28N 121.97W > > Yes, the ratio is the same. The ratio of 1 to sin(lat) is the same as the > ratio of 1/sin(lat) to 1. > > But I think Anselmo makes one small error. Yes, the points at step 4 are the > hour marks of an analemmatic dial if, by 'horizontal lines' he means > east-west lines, but to draw a Horizontal Sundial you want to draw > north-south lines from the inner points and east-west ones from the outer > points. > This is because an analemmatic dial's major (longer) axis is east-west, > whereas for a horizontal dial constructed this way the major axis is > north-south. > > Chris Lusby Taylor > 51.4N 1.3W > > - > -
Re: your webpage
Hi John, Yes, I know and this is why a suncompass works. It's one scale of date with a number of ellipses for different latitudes around it. With one remark. At higher latitudes the length shrinks and final to zero at latitude 90. And look at the formula: y = a cos phi . tan decl a cos phi is constant for a certain dial so y always is proportional to tan decl. But your remark is a very practical help to simplify the job. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "John Carmichael" <[EMAIL PROTECTED]> To: Sent: Monday, June 02, 2003 9:57 PM Subject: Re: your webpage > Hi Helmut & others: > > I'm sure you probably know this already, but one neat and helpful thing I > learned about analemmatic date line construction is this: > > > > All analemmatic dials at every latitude and of every size use the same date > line; the only difference is in the length of the line which becomes longer > (in relation to the ellipse) at higher latitudes and with bigger dials. But > the date line is the same for all. The distance between the date markings is > proportionally the same, no matter what length the date line. > > > > In other words, you don't have to redraw the date line everytime you design > an analemmatic for a different latitude or of a different size. You just > need one drawing and you can use it as a template for any analemmaic dial. > All you need to do is to change its size. If you use Delta Cad or > photocopyers, this is an easy operation. > > > > To determine the length of the date line is simple. First, you determine the > location of a focus point using traditional methods or Fer's Delta Cad > macro. Then draw a horizontal line to the center of the dial (the > North/South Meridian). This point is the equinox date on the date line and > is at the center of the line. Then draw an angled line from the focus that > is 23.44 degrees from horizontal. Where this line crosses the meridian is > one end of the date line and marks a solstice date. Measure an equal > distance in the other direction an this is the other end of the line and is > the other solstice date. The distance between these two points is the length > of the line. > > > > Then just blow up or shrink the size of your template drawing so that it is > the same length. Simple! And this saves a lot of work. > > > > Note: Here is a PDF of my Delta Cad Date Line Template. Of course you can > change font type and scale if desired. And you can have the option of a > clockwise or counterclockwise date notation. Both are shown here. > > > > John > > John L. Carmichael Jr. > Sundial Sculptures > 925 E. Foothills Dr. > Tucson Arizona 85718 > USA > > Tel: 520-696-1709 > Email: [EMAIL PROTECTED] > Website: <http://www.sundialsculptures.com> > - Original Message - > From: "Helmut Sonderegger" <[EMAIL PROTECTED]> > To: > Sent: Monday, June 02, 2003 3:52 AM > Subject: your webpage > > > > Fer, > > I just had one more look on your webpage with the information on > analemmatic > > sundials. Therefore my question: Why did you not include the formula for > the > > date points of the dial? I know, one can see that very easy from the > images > > there, but perhaps it would be of some help for some visitors of this > page. > > > > sunny greetings > > Helmut > > > > - > > > -
Re: your webpage
Helmut, No idea why I didn't add the formulas but now they are. Thanks for your remark. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Helmut Sonderegger" <[EMAIL PROTECTED]> To: Sent: Monday, June 02, 2003 12:52 PM Subject: your webpage > Fer, > I just had one more look on your webpage with the information on analemmatic > sundials. Therefore my question: Why did you not include the formula for the > date points of the dial? I know, one can see that very easy from the images > there, but perhaps it would be of some help for some visitors of this page. > > sunny greetings > Helmut > > - > -
quadrants
Helmut, Yes, there are quadrants with straight hourlines. In the bulletin of De Zonnewijzerkring nr 10, october 1981 an overview of quadrants is given by Hans de Rijk. He points to: The Horarium Bilimbatum as published in Protomathesus by Fineus Orontius, 1532. This is noted in Bobinger, Alt-Augsburger Kompassmacher, page 50 where you find a small picture of it. A look alike is in the book Orologi Solari van Girolamo Fantoni, page 366. Another quadrant of this type is made by Metz. Here you also see straight azimuth lines in a separate part of the quadrant. As I think to remember such quadrants are correct for noon. The date scale is constructed according the sun's altiudes at noon. For the other hourlines construct correct points for the solstices and just draw the straight line. These hour lines then are aproximations. I think this also is the fact with quadrants with circular hourlines. Construct the correct noon arc and date scale. For other hour lines construct three points for the solstices and equinox. Just draw the arc through these three points. Best wishes, Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Helmut Sonderegger" <[EMAIL PROTECTED]> To: Sent: Saturday, May 31, 2003 10:03 PM Subject: Re: unequal hour lines > Sara, > in my software, which is also on the NASS-repository, I draw quadrants with > temporal hour lines point by point. The circles are aequidistant date lines > (not declination lines itself). The hour lines are evaluated by computing > the day length of the particular days used and then divided by 12. Then the > Sun's altuitude for these hour points is calculated. This method is rather > simple for computers, but in this case I guess no simple formula for the > hour lines can be found. > > The type of the resulting hour lines of course depends on the arrangement of > the arcs for the date lines or declination lines. In old quadrants > aequidistant declination lines are used and then arcs of circles seem to be > used for hour lines. As I do not now any literature about the exactness of > this > construction: Does anybody know such literature? > > It would be an interesting question too if an arrangement of the date lines > can be found where all hour lines become straight lines or at least nearly > straight lines. Does anybody know an answer? > > Helmut > Mail: [EMAIL PROTECTED] > Web: http://webland.lion.cc/vorarlberg/28/sun.htm > -
Re: unequal hour lines
Sara, For sundials, although not your question, I calculate antique hourlines point by point. Then it's good to see that at higher latitudes the lines aren't straight lines. For a tympan of an astrolabium I draw them as arcs by deviding the daylight parts of the solstice circles and equinox circle in 12 parts. So I find three points to draw each hour arc. On the dorsum af an astrolabium often a famous circular construction for antique hours is found, however, not correct for times other then at the solstices and equinoxes. For a quadrant I never have constructed the antique hourlines. I did construct such lines in a nomogram as done by Peter Apian or Johann Stab and others as you may read in Compendium vol.5 nr. 4 december 1998. There the line representing the daylight part is devided in 6 equal parts. In the book by Joseph Drecker, Die Theorie der Sonnenuhren, 1925, you may find analytical formulae for the antique hourlines but not practical for use in construction of a sundial, quadrant or astrolabium. I hope this is of help to you. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Sara Schechner" <[EMAIL PROTECTED]> To: Sent: Thursday, May 29, 2003 2:55 PM Subject: unequal hour lines > Hi, > I am working on a project that involves the traditional unequal hour lines > (also known as seasonal and temporal hours) on a horary quadrant and an > astrolabe. In other words, I want to get the right arcs for use on an > instrument that measures altitude of the sun and makes use of a solar > declination scale along the radius of the instrument. These arcs would be > latitude specific, as on traditional instruments. > > What techniques have list members found to construct them? Do you use data > points plotted? geometric construction? > > Thanks for the advice and input!! > > Happy Dialing, > Sara > 42.38 N, 71.13 W > Sara Schechner, Ph.D. > David P. Wheatland Curator > Collection of Historical Scientific Instruments > Harvard University, Science Center B-6 > 1 Oxford Street, Cambridge MA 02138 > 617-496-9542 (Tel) > 617-496-5932 (Fax) > > - > -
Re: Judith Romano's Analemmatic Garden Sundial
Title: Message Ronitz, Suppose you live at longitude -5 and time zone -15 degrees. Both are East longitudes. Your longitude is 10 west of the time zone meridian. Then input something llike 70 for longitude and 60 for time zone. Add n*15 degrees both. In this example n = 5. Then the longitude also is 10 west of the time zone meridian. The drawing should be the same. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: Ronit Maoz To: sundial@rrz.uni-koeln.de Sent: Saturday, May 24, 2003 5:12 PM Subject: Judith Romano's Analemmatic Garden Sundial Dear Judith Romano and Sundial members, I tried making the garden sundial , which I found on the internet, according to the plan given by you (Judith Romano). The figures came out funny... Only then did I read, that this program is intended for Western Longitudes. Is this the reason why the figures didn't fit? If that's the case, is there a way of "correcting" the program or perhaps, is there another accurate program for analemmatic garden sundials suitable for Northern Latitudes , Eastern Longtitudes? Sincerely, Ronit Maoz
Re: Julian Date and UbiSol
John, You wrote: > I notice that Jean Meeus is also particular about referring to JD as > Julian Day rather than Julian Date. In a note Jean Meeus writes in his book: --- In many books we read 'Julian Date' instead of 'Julian Day'. For us, a Julian date is a date in the Julian calendar, just as a Gregorian date refers to the Gregorian calendar. The JD has nothing to do with the Julian calendar. --- I also think it is better to use Julian Day. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "John Hall" <[EMAIL PROTECTED]> To: Sent: Sunday, April 27, 2003 5:20 AM Subject: Re: Julian Date and UbiSol > Thank you Fer for such a clear and concise explanation. > > On Sunday, April 27, 2003, at 12:17 AM, fer j. de vries wrote: > > > > The difference is there is no difference. > > > > January 1st -4712 is the same as January 1st 4713 BC > > ( I think the 4173 in your message is a typo error) > > It certainly was - I only noticed it after the message had been posted. > > > > Atronomers count including the year 0 so the year before 1 is 0 and > > the year > > before that is -1. > > > > Historians count without the year 0 so the year before 1 is 1 BC and > > the > > year before that is 2 BC. > > > > Therefore we get two starting points for the Julian day: > > -4712 > > 4713 BC > > > > Jean Meeus uses the astronomical way because it's easier to calculate > > the JD > > for the Julian calendar. > > I notice that Jean Meeus is also particular about referring to JD as > Julian Day rather than Julian Date. > > By the way is the second edition of his book much changed from the > first edition ? Can anybody help with a comparison of the two editions. > > - > -
Re: Julian Date and UbiSol
Hi John, The difference is there is no difference. January 1st -4712 is the same as January 1st 4713 BC ( I think the 4173 in your message is a typo error) Atronomers count including the year 0 so the year before 1 is 0 and the year before that is -1. Historians count without the year 0 so the year before 1 is 1 BC and the year before that is -2 BC. Therefore we get two starting points for the Julian day: -4712 4713 BC Jean Meeus uses the astronomical way because it's easier to calculate the JD for the Julian calendar. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "John Hall" <[EMAIL PROTECTED]> To: Sent: Saturday, April 26, 2003 9:39 AM Subject: Julian Date and UbiSol > Anselmo I have a couple of questions about your UbiSol Julian Date > (Julian Day). The result for 2003/04/26 seems to be at odds with other > calculators. > > UbiSol = JD 21478.5 > Meeus and others = JD 2452755.5 > > You and other respected references state this date is calculated from > January the 1st 4173 BC. Meeus in his first edition of Astronomical > Algorithms on page 59 states this is calculated from '... the > beginning of the year -4712' > > Can somebody please help me with an explanation ? > > Confused of Tasmania > 41.5 South 147.1 East > > - > -
Re: Web of the Amigos de los Relojes de Sol Society
Anselmo, At our WEB site we have already a link to your site. Your site give a lot of interesting information. Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Anselmo Pérez Serrada" <[EMAIL PROTECTED]> To: Sent: Friday, April 04, 2003 11:28 PM Subject: Web of the Amigos de los Relojes de Sol Society > Dear dialists, > > Some weeks ago we've uploaded the web of the 'Amigos de los Relojes de > Sol' Society > at > > http://www.relojesdesol.org > > It is still under construction, but maybe these of you who understand > Spanish would like > to take a glance at it. Of course, corrections, suggestions and > non-redundant collaborations > are welcome (you can write to [EMAIL PROTECTED]) > > Provided that our society is NOT a National Society but it is open to > all enthusiasts of > Sundials this message would seem rather schizo-glothic or even absurd. > Well, the > point is that almost all of our contents are written in Spanish: so it > would take an unaffordable > amount of work to translate them into English and it would be equally > absurd to have only > the headlines written in English and the core in Spanish! > > Anyway, we'd be VERY grateful if you include us in your links. > > Best regards, > > Anselmo Perez Serrada > > - > -
Re: Graeco-Roman Sundials
Ronit,
That's very easy to do.
Mount through the top of the pin gnomon a temporary
polestyle with a rotatable plane on it.
If this plane is vertical to the bottom it is the noon shadow
plane.
The intersection with the cone is the hourline for
noon.
Rotate the shadow plane in steps of 15 degrees to get all the
other hourlines.
Best wishes, Fer.
Fer J. de Vries
De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl
Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven,
Netherlandslat. 51:30 N long. 5:30
E
- Original Message -
From:
Ronit
Maoz
To: sundial@rrz.uni-koeln.de
Sent: Wednesday, March 19, 2003 4:41
PM
Subject: Re: Graeco-Roman Sundials
Fellow Shadow-Watchers,
Any idea how to make a Greek -Roman sundial with modern
hours instead of temporary?
Ronit Maoz
- Original Message -
From:
fer j. de vries
To: sundial
Sent: Friday, March 14, 2003 8:33
PM
Subject: Re: Graeco-Roman
Sundials
Phil,
A conical sundial also may be "wedged" at another latitude
but it still reads the unequal or antique hours of the original
location.
So you can't use the dial at its new location for the time
system used at that place.
The antique hours are of different length at the two
latitudes.
In the contrary our modern hours are of the same time
system at all latitudes and the "wedged" dial can show the correct
time at the new location.
I am not sure how in older times the conical dials were
realy made but it is easy to draw the circles for the equinoxes and
solstices, parallel to the front side.
This front side has an angle to the horizontal plane
of 90 - lat.
Divide these circles in 12 parts and connect the points
with the hourlines.
At least, this is true if the gnomon ends on the axis
of the cone and in the horizontal top plane.
Best wishes, Fer.
Fer J. de Vries
De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl
Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven,
Netherlandslat. 51:30 N long.
5:30 E
- Original Message -
From:
Phil Walker
To: Sundial, List
Sent: Friday, March 14, 2003 11:53
AM
Subject: Graeco-Roman Sundials
Fellow Shadow-Watchers,
I have recently become interested in Graeco-Roman
conical dials, but my maths is not good enough to be certain about a
couple of points. Can someone out there help me
?,
In modern horizontal dials, if the dial is moved to a
different latitude, it is quite usual to be able to adjust the plate by
wedging it out. Is there any reason why the same approach could be
adopted in ancient times to correct, for example, conical dials moved
from the intended location to the another place ?
How would the craftsman draw the
temporal hour curves on a conical dial, given the latitude and the
cone's parameters ? I can understand the method for
ancient horizontal dials but conical as yet defeat me
!
Yours gnomonically
Phil WalkerNewport, Shropshire, U.K.Lat:
52deg. 46min. NorthLong: 2deg. 22min.
West
Re: Graeco-Roman Sundials
Phil, A conical sundial also may be "wedged" at another latitude but it still reads the unequal or antique hours of the original location. So you can't use the dial at its new location for the time system used at that place. The antique hours are of different length at the two latitudes. In the contrary our modern hours are of the same time system at all latitudes and the "wedged" dial can show the correct time at the new location. I am not sure how in older times the conical dials were realy made but it is easy to draw the circles for the equinoxes and solstices, parallel to the front side. This front side has an angle to the horizontal plane of 90 - lat. Divide these circles in 12 parts and connect the points with the hourlines. At least, this is true if the gnomon ends on the axis of the cone and in the horizontal top plane. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Homemailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/index-fer.htmEindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: Phil Walker To: Sundial, List Sent: Friday, March 14, 2003 11:53 AM Subject: Graeco-Roman Sundials Fellow Shadow-Watchers, I have recently become interested in Graeco-Roman conical dials, but my maths is not good enough to be certain about a couple of points. Can someone out there help me ?, In modern horizontal dials, if the dial is moved to a different latitude, it is quite usual to be able to adjust the plate by wedging it out. Is there any reason why the same approach could be adopted in ancient times to correct, for example, conical dials moved from the intended location to the another place ? How would the craftsman draw the temporal hour curves on a conical dial, given the latitude and the cone's parameters ? I can understand the method for ancient horizontal dials but conical as yet defeat me ! Yours gnomonically Phil WalkerNewport, Shropshire, U.K.Lat: 52deg. 46min. NorthLong: 2deg. 22min. West
Re: NASS Compendium
Fred, Thanks for this link. There are even some Dutch sundials in this list. Best, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Fred Sawyer" <[EMAIL PROTECTED]> To: "Sundial List" Sent: Monday, March 03, 2003 5:42 PM Subject: NASS Compendium > The March issue of the NASS Compendium has been delayed so that we can wait > for a good number of late renewals to come in. In the meantime, I thought > that readers on this list might be interested in the following excerpt from > one of the notes (on the 'new sport' of geocaching) in the upcoming issue: > > "In fact, there is a virtual cache specifically for sundials. It is "log > anywhere", meaning it does not pertain to a specific dial location. To get > credit for finding this cache, you need to find a 'unique' sundial (nothing > mass-produced), take a photo of the dial with your GPS receiver in the > picture, give a brief history and then post the picture and GPS coordinates > at www.geocaching.com/seek/cache_details.aspx?ID=26100. So far, there are > 122 loggings of this cache - and that means 122 sundials with photo and > exact latitude and longitude information. It's interesting to read that a > number of the players found their dials by checking the NASS Registry > (sundials.org). Still others have found sundials that have not yet appeared > in the registry." > > Fred Sawyer > > > - > -
Re: Sundials in Manchester of all places
Another example of such a "sundial" is in Amersfoort, Netherlands. Go to the new site of "De Zonnewijzerkring" (Address below) Follow the link Links / Members / Fer de Vries / Sunpointer at Railwaystation. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: <[EMAIL PROTECTED]> To: Sent: Thursday, January 16, 2003 12:50 PM Subject: Re: Sundials in Manchester of all places > I see that the caption to a photograph on the Manchester news web page > (www.manchesteronline.co.uk/news/stories/Detail_LinkStory=48875.html) tells > us that Craig Martin's sundial works at night, Wow! > - > -
WEB site moved
Hello All,The WEB site of De Zonnewijzerkring, (The Dutch Sundial Society), has beenrebuilt and got a new address. http://www.de-zonnewijzerkring.nl If you have a link on your WEB site to the site of De Zonnewijzerkring please change the link with the new URL. For the time being the old address will still function and you will be directed to the new address but this won't last for ever. The new site is in two languages, English and Dutch. At the start page you make your choice. This page or the next page can be saved as one of your favorites. The new site uses frames and just using the menu's you easily may reach all the pages.The site isn't complete yet. We keep on building and our members have to writeabout interesting things they want to show to you.Archives will be built up of the dials and small articles our members write about. We hope you will enjoy it and please send us your remarks.Best wishes to all, Fer. E-mail addresses: mailto:[EMAIL PROTECTED] or mailto:[EMAIL PROTECTED] Fer J. de Vries Home:mailto:[EMAIL PROTECTED]http://www.iae.nl/users/ferdv/Eindhoven, Netherlandslat. 51:30 N long. 5:30 E
Re: Pingre Sundial
Anselmo, You may find a picture in Compendium, vol. 6, nr. 1, march 1999 in an article by Fred Sawyer, translated from a French article by Denis Savoie. Title: The Old Sundial Of Catherine de Medicis' Column In Paris Fer J. de Vries mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/ Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Anselmo Pérez Serrada" <[EMAIL PROTECTED]> To: Sent: Sunday, January 12, 2003 6:35 PM Subject: Pingre Sundial > Hi dialists! > > Could anyone point me to some picture of a Pingre Sundial (maybe the > original one in Paris)? > > Best regards > > Anselmo Perez Serrada > > - > -
Polar dial
Hi Mac and Others,, As a contribution to the discussion about the polar dial I made a drawing of the construction of such a dial. In this picture I try to explain what I did. At the left from top to bottom you find a series of gnomons for each hour starting at noon with the appropriate hourline with date points for the solstices and equnioxes. The lengths of the gnomons are as Bits formula ( graphic 11, bottom) gn = g . cos t Now all the hourlines with datepoints are equal, only the place and length of the gnomons is different. In the middle top figure these gnomons and hourlines are placed on a north-south line, using the formula an = g . sin t . tan alpha. with alpha = 45. The distance between the footpoints of the gnomons aren't equal. In that case we get the pattern as by Oyen. The shape of the line through all the endpoints of the hourgnomons is a semi-circle. The second half of the pattern is added in the figure middle bottom. The difference with the figure by Bits is that he had all the gnomons equidistant as may be seen at the left in graphic 8. Now shift the gnomons and hourlines with datepoints according the formula by Bits for delta-x and delta-y and the result is in the figure right bottom. The footpoints of the hourgnomons are drawn in red. The footpoints for 6 and 18 are arbitrary because the gnomonlength is 0. Now it's easy to draw a side vieuw of the wire. We know the distance of the footpoints from the center point and the lengths of the hourgnomons. The figure at top right shows roughly the result in blue Reading the time before about 7 am and after 5 pm is difficult because the length of the hourgnomon is small. If I didn't make a mistake I conclude that the principle by Bits is all right but his drawings are some misleading. Best wishes, Fer. Fer J. de Vries mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/ Eindhoven, Netherlands lat. 51:30 N long. 5:30 E Attachment converted: Macintosh HD:polar.gif 1 (GIFf/JVWR) (0006792E)
Re: Quest for a civil time polar sundial, continued...
Hi Chris, Thanks for the picture of your universal polar dial for civil time. You name this one a kind of a bifilar dial which may be correct if you assume the line where you read the time to be one of the fillars. However, I would call this dial an equant dial as developed by Fred Sawyer about 20 years ago. With that idea many kinds of dials can be constructed and not only the polar dial. The recent discussion however is more or less limited to the polar dial with parallel hourlines but thanks for your contribution. Best wishes, Fer. Fer J. de Vries mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/ Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Chris Lusby Taylor" <[EMAIL PROTECTED]> To: Sent: Thursday, January 09, 2003 11:51 AM Subject: Re: Quest for a civil time polar sundial, continued... > A mean time polar sundial without curved hour lines is possible, if the user > is permitted to adjust it for the EoT. It can show Summer Time / Daylight > Saving Time, too. > > The dial I propose is entirely fixed except for a circular dial plate that > rotates about its centre. This is much easier to make than a polar mount. > Like all polar dials, it is universal. > > I have taken the liberty of attaching a small (13KB) GIF file that shows the > dial. It is a form of bifilar dial, though you would hardly guess that to > look at it. > > Chris Lusby Taylor > Newbury, Berks., England > 51.4N, 1.3W > > > -
Re: Quest for a civil time polar sundial, continued...
Hi Thibaud, Because there are datelines on the dial it is possible to draw ananalemmas around the hourlines to correct for EoT. Or use two dialplates with half the analemma for each half of the year. But it was asked to construct the EoT corretion in the gnomon and to keep straight hourlines and I think that's not possible with the wire gnomon of Bits. For each day the complete wire is used because it is built with infinite "hourgnomons". For a specific day you may correct the wire for the EoT of that day but for the next day you need to construct another wire. It's a daily job to change the wire and that's too much for a simple gnomonist. Best wishes, Fer. Fer J. de Vries mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/ Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Thibaud Taudin-Chabot" <[EMAIL PROTECTED]> To: Sent: Wednesday, January 08, 2003 8:51 PM Subject: Re: Quest for a civil time polar sundial, continued... > Hi Mac and other readers of this continuing story... > > That was a good thought to prepare that resume on the web, I could read it > in peace. > It gave me some thinking and I put down my thoughts so other people might > come to new ideas. > > A polar dial which reads civil time and constructed with one dial/style is > not possible because the datescale on sundial is in fact a declination > scale. For each declination there are two dates involved so there are two > different timeequation values involved. John stated already no analemmas, > so it has to be a single line for two different corrections. Sorry, I think > that is indeed not possible. > But why not make two polar dials, each with a different pattern. One > for the summer/autumn and one for the winter/spring. > It might even be the same polar dial with interchangeable > gnomon/style/shadowwire. > Take the dial constructed by W. Bits: each our line can be shifted with the > longitude correction and a slight additional shift for the timeequation. Do > this for summer/autumn. Then calculate bachwards how the wire should be in > winter/spring. If these two different two wires are used in the correct > period the polar dial should read civiltime, or make two polar dials with > fixed wires. > Anybody who thinks this might be possible? > > Thibaud Chabot > > > At 16:08 07-01-2003 -0500, you wrote: > >7 Jan 03 > >Hello Friends, > > > >On December 29 I mistakenly sent to the entire sundial mailing list a > >message intended for one member, Dave Bell. In that message I asked Dave > >if he would be willing to post some materials I had collected concerning > >the problem of finding a shaped gnomon to give civil time directly on a > >polar dial. > > > >Due to a misunderstanding on my part, I announced that such a gnomon had > >been designed about 20 years ago. Alas, we still are looking for a > >solution. If you have any interest in seeing a report on our search so > >far, point your browser at > > > >http://advanceassociates.com/Sundials/A_Civil-Time_Polar_Dial/ > > > >or, for slow typists > > > >http://tinyurl.com/46ss > > > > > >Dave Bell has provided the space, and has taken the time and trouble to > >set up the webpage. I greatly appreciate his assistance with this web > >posting. But any errors are my responsibility, so contact me if you find > >mistakes. General comments are also welcome. > > > >I wish to thank John Close for raising the question, to thank all those > >who contributed to the material posted, and I extend a special thank you > >to my good friend Fer de Vries for providing the quoted text. > > > >Best wishes, > > > >Mac Oglesby > > > >P.S. Please let the sundial list members know if any of you have other > >information to share concerning this problem. > > > >- > > - > Thibaud Taudin-Chabot > 52° 18' 19.85" North, 04° 51' 09.45" East, alt. -4.50 m > home email: [EMAIL PROTECTED] > > > - > -
Re: Quest for a civil time polar sundial
John, Don't move the gnomon to correct for EoT or whatsoever. Move the hourlines. Or move the gnomon including the datelines. Fer. Fer J. de Vries mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/ Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "jcclose" <[EMAIL PROTECTED]> To: Sent: Wednesday, January 08, 2003 10:38 AM Subject: Re: Quest for a civil time polar sundial > Hello Mac, > The puzzle gets more interesting each day! I was particularly > intrigued by Graphic 5. The dial with a curved wire gnomon. I'm having > trouble visualising the 3D shape of the wire. Pity the Dutch Diallists > hadn't added a front view and a top view. Please could you tell me how this > shape allows for equally spaced hour lines throughout the day. > I hope this means if this system works an EoT, BST and Longitude > correction could be achieved simply by moving the gnomon along the dial > either east or west. > Cheers > John > - Original Message - > From: "Mac Oglesby" <[EMAIL PROTECTED]> > To: "Sundial List" > Sent: Tuesday, January 07, 2003 9:08 PM > Subject: Quest for a civil time polar sundial > > > > > > 7 Jan 03 > > > > Hello Friends, > > > > On December 29 I mistakenly sent to the entire sundial mailing list a > > message intended for one member, Dave Bell. In that message I asked > > Dave if he would be willing to post some materials I had collected > > concerning the problem of finding a shaped gnomon to give civil time > > directly on a polar dial. > > > > Due to a misunderstanding on my part, I announced that such a gnomon > > had been designed about 20 years ago. Alas, we still are looking for > > a solution. If you have any interest in seeing a report on our search > > so far, point your browser at > > > > http://advanceassociates.com/Sundials/A_Civil-Time_Polar_Dial/ > > > > or, for slow typists > > > > http://tinyurl.com/46ss > > > > > > Dave Bell has provided the space, and has taken the time and trouble > > to set up the webpage. I greatly appreciate his assistance with this > > web posting. But any errors are my responsibility, so contact me if > > you find mistakes. General comments are also welcome. > > > > I wish to thank John Close for raising the question, to thank all > > those who contributed to the material posted, and I extend a special > > thank you to my good friend Fer de Vries for providing the quoted > > text. > > > > Best wishes, > > > > Mac Oglesby > > > > P.S. Please let the sundial list members know if any of you have > > other information to share concerning this problem. > > > > - > > - > -
Re: A sundial in Mercury
Hi Dave,
There is a real story like this.
I quote from my WEB site:
-
Eise Eisinga (1744 - 1828), Netherland. Eise Eisinga was an autodidact, who,
by 18 years of age, had already written his book with many drawings of plane
sundials, titled: "Gnomonica of Sonnewijsers, alle door passer en lijnjaal
afgepast op de Noorderbreedte van Dronrijp, 53° - 13', 1762." ("Gnomonics or
Sundials, all constructed by compasses and ruler for the Northern latitude
of Dronrijp, 53° - 13', 1762.")
The book comprises 170 large pages, nearly all filled with drawings of plane
sundials, all for the same latitude, but for several declinations and
inclinations of the planes, and almost all provided with lines for the sun's
declination. On page 170 he drew the Capuchin card dial discussed here.
His most famous accomplishment was building the planetarium at Franeker,
Netherland. He wanted to show the real things that were happening in the
sky. He constructed this planetarium on the ceiling of the living room of
his house. Around the sun, the planets Mercury, Venus, Earth with Moon,
Mars, Jupiter and Saturn run in real time, all driven by a mechanical clock.
Several other instruments are placed upon the walls of the room. They show
the time of sunrise and sunset, the phases of the moon, the time the moon
rises and sets, and include many other interesting astronomical phenomena.
It took Eisinga 7 years, from 1774 to 1781, to complete his task, all done
in his spare time after his day's work. World-renowned, this unique
planetarium is still in running order, and its moving display is the focal
attraction of the museum.
-
See also Compendium, volume 6, number 1, 1999 :
At that time at sunrise, on a sunday, all known planets rose with the sun.
It was predicted that the world would be in flames and people got in panic.
Than Eise Eisinga dicided to show the real things that happens with his
planetaruium.
The planetarium is, after a recent restoration, still running after so many
years.
Best wishes, Fer.
Fer J. de Vries
mailto:[EMAIL PROTECTED]
http://www.iae.nl/users/ferdv/
Eindhoven, Netherlands
lat. 51:30 N long. 5:30 E
- Original Message -
From: "Dave Bell" <[EMAIL PROTECTED]>
To:
Sent: Monday, January 06, 2003 8:46 PM
Subject: RE: A sundial in Mercury
> On Mon, 6 Jan 2003, Roger Bailey wrote:
>
> > Hi Anselmo,
> >
> > Your note reminded me of Asimov's classic story "Nightfall" which is
based
> > on a variation on this theme. In a multi-sun universe, people panic and
> > civilization collapses when all the suns set, night falls and the stars
> > shine in the dark sky.
>
> "Dark sky" taken figuratively here, since the planet in the story was
> situated in the middle of a globular cluster. As I recall (and it's been
> far too long since I read the story!), it went something like this:
>
> All the local pundits discounted the lone(?) prophet of disaster. They
> went so far as to build theatres in which the room was darkened and a
> planetarium sky was projected, much like ours, to demonstrate how
> non-threatening the situations was. The overwhelming impact of the
> thousands upon thousands of nearby, bright stars was what triggered the
> final panic - just as had been predicted from certain ancient writings.
>
> Dave
> 37.28N 121.97W
>
> -
>
-
Re: sundial classification
Dear Sara, This is one of the most difficult problems in gnomonics and any list of definitions will be arbitrary. The subject has been discussed on the list before. I write down some notes but I have no idea if they are of some help for your specific work. To me an important classification is: - polestyle dials - nodus dials. and of course combinations of both. This mainly covers the flat sundials on buildings or on a pedestal in a garden or on a square, however, also curved planes can have dials of these kinds. And e.g. a diptych dial usually has 2 pole style dials and sometimes also one or more nodus dials in it. If I should write a book about sundials on buildings I should use defintions as: (Vertical) south, north, east, west, declining, inclining and so on together with pole style or nodus dial. But in a cataloque as you are building more descriptive definitions as yours will be necessary. So it also depends on the aims. Oughtred dials, analemmatic dials, Foster dials may be classiified as equatorial projection dials. Oughtred-type dial (also called the "double horizontal dial") is a combination of an horizontal polestyle dial and an horizontal equatorial projection sundial. What is an Augsburg-type? In Augsburg many types of dials has been made. Best wishes, Fer. Fer J. de Vries mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/ Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Sara Schechner" <[EMAIL PROTECTED]> To: Sent: Sunday, January 05, 2003 6:24 PM Subject: sundial classification > Dear Friends, > In preparation for a catalogue of historical sundials, I have been > organizing the dials into classes based on the principal feature of the > celestial sphere or altazimuth coordinate projected onto the dial > surface. I would like your feedback on the list below. > > It appears to me that self-orienting sundials combine two distinct > projections. Do you agree? What are they in the specific cases? > > Here's the draft list followed by the ones I have questions about: > > I. Directional sundials--project the hour angle of the sun onto the dial > surface > horizontal--particular (fixed latitude) > plate > garden > string-gnomon > compass > floating > cannon > reclining > horizontal--universal (multiple latitudes) > Butterfield-type > inclinable > vertical--particular (fixed latitude) > direct south (north, east, west) facing > declining > equatorial--particular > garden inclined plate > bow-string or crossed-Cs form > equatorial--universal > universal equatorial > Augsburg-type > Augsburg-type with cam > mechanical equatorial > spherical or globe > polar--particular > multiple-faced--particular > polyhedral > cruciform > cube > multiple-faced--universal > diptych > polyhedral inclinable > cube inclinable > cruciform inclinable > > II. Altitude sundials > [generally for particular latitudes but some can be made universal] > ring > pillar > vertical plate > vertical disk > rectilinear--Capuchin > rectilinear--Regiomontanus-type > rectilinear--navicula > De Rojas-type > scaphe > horary quadrant > > III. Azimuth sundials > simple azimuth--particular > pin-gnomon ?? > analemmatic ?? > magnetic azimuth--particular > magnetic azimuth and universal multiple-faced > Bloud-type diptych > > IV. Astronomical compendia--instruments that combine multiple time finding > instruments, maps, or mathematical tables in a single package. > > > Here are the problematic ones for me-- Where should these be placed? > > Universal ring dials and crescent dials--these are self-aligning, and so > must be more than simply directional equatorial dials. Are they > combinations of hour-angle and altitude sundials, or something else? > > horizontal (or vertical) pin-gnomon--e.g. a sundial with a > vertical-(horizontal)-stick gnomon > often used to display Italian or Nuremberg hours > or to show time and date (or place of sun in zodiac) or lengths of daylight. > > ?? is this an azimuth dial?? > > Oughtred-type dial (also called the "double horizontal dial") --a > combination of a a horizontal plate dial with a polar gnomon and one with a > vertical-stick gnomon--self-aligning > ?? is this a combo hour-angle and azimuth sundial?? > > Analemmatic dial (modern form) with elliptical hour scale--is this an > azimuth dial? > Analemmatic dial (historical form) is a combination of a directional > horizontal sundial plus an elliptical analemmatic sundial on the same > plate. It is self-aligning. > > Heliochronometer--standard definition? A solar chronometer that uses the > sun to find mean time directly. Where would this go in the > classification? An equatorial dial with a date cam? > > Thanks for the help! > Sara > > - > -
Re: Fer's 1982 Dial
Hi Bill, A part of the story I know. The company Authentic Models in our country wanted in the 1980's a replica of an old sundial that is in the Smithsonian in Whasington, USA and they got permission to do that. That dial was made by R. Glynne in the time that the Julian calendar was still in use. This may be seen at the EoT table on the dial which is for that calendar. They made beautiful and technical photo's of the dial and I was asked to make a drawing of it and that I did. At that time I just started seriously with gnomonics and it was a challenge for me to see what I could do. The drawing was made by hand, a computer at that time to help me wasn't there. I tried to make the division of the time scale in minutes as the original also was in minutes but than the scale looked irregular so I made a two minutes division. The dial was calculated for about 51 degrees latitude, I don't remember exactly. I hope you will enjoy your example. About Glynne I once got a note as is below: Richard Glynne (1681-1755), was apprenticed to Henry Wynne in 1696 in the Clockmakers' Company of which he became free in 1705 and was steward in 1725. He worked first at the sign of the Atlas and Hercules (1712-16) In Cheapside and subsequently (1718-29) opposite Salisbury Court in Fleet Street, London. On obtaining his freedom in 1705, he married Anne Lea, the daughter of the noted map and globe-sellers Philip and Anne Lea. From at least 1712 he was working in association if not in formal partnership, with his mother-in-law, advertising a new pair of globes in 1712, and publishing and marketing maps. In parallel with this activity, he made and sold 'all sorts of Mathematical instruments, either for Land or Sea, according to the newest improvements' as he stated in an advertisement in 1726. A variety of mathematical instuments by Glynne are indeed known. All are of high quality, with clean, well executed engraving uncluttered by extraneous decoration. Glynne's fine instruments recommended themselved to a fashionable clientèle, and he was sufficiently successful to be able to retire at the relativey early age of 49 in 1730, his stock being auctioned at the shop of the optician Edward Scarlett in the same year. Fer. Fer J. de Vries mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/ Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: <[EMAIL PROTECTED]> To: Sent: Thursday, January 02, 2003 4:35 AM Subject: Fer's 1982 Dial > At Christmas I received a stocking stuffer of a small mass produced brass > dial on a marble base. I had to unscrew the gnomon to safely pack it in my > suitcase, and saw underneath the gnomon in almost microscopic letters "F J de > Vries 1982". The dial seemed to be a reproduction of an old high latitude > (>50 degrees) dial. Several stickers on the dials' underside had fallen of, > but a remaining sticker said "Made in Taiwan for Authentic Models" > > So, is there a story behind this, Fer? > > Bill G. > - > -
Re: Forwarding some questions, re. sundial 'equinox accuracy'
Signe Best, On a sundial it is possible to show when spring starts. For this you need a line for the sun's declination = 0 degrees. Perhaps you could reach an accuracy of 1 or 2 days. But now there is the problem to translate this to a date. If you count the number of days from spring equinox to spring equinox the answer will be somewhat of 365.25 days. After 4 years the date for the equinox is one day off. It's for this reason we use the leap year with one extra day. So to get the date for spring from a sundial you always will have this extra inaccuracy. Best wishes, Fer. Fer J. de Vries mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/ Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Mr. D. Hunt" <[EMAIL PROTECTED]> To: Sent: Monday, December 30, 2002 3:04 PM Subject: Forwarding some questions, re. sundial 'equinox accuracy' > > Our sundial business regularly receives questions via our Website, (mainly > from pupils wanting us to help with school projects) - but I am forwarding > this one to the "Sundial Mailing List", as it is more unusual than normal. > > > > From: "signelerin" <[EMAIL PROTECTED]> > > > Date: Sun, 29 Dec 2002 16:30:15 -0600 > > > > My name is Signe Best, and I am hoping you will be able to answer a > > few questions I have about sundials and the shadows they cast at > > certain times of the year. > > > I understand that the time of the equinox is the moment the sun's > > shadow becomes exact with the line of the equator making day and night > > of nearly equal length (12 hrs), and the exact point when winter becomes > > spring. The official equinox date varies from March 20-22 according to > > the US Naval Observatory. Will the literal observation of a sundial > > pinpoint more accurately than 3 days ? If this sundial was set up in > > Jerusalem, would it show the exact day that winter ends and spring > > begins ? Has anyone counted the days according to a sundial from the > > 1st day of spring one year to the 1st day of spring the next ? Will > > this always be the same amount of days ? Have you ever recorded the > > moment when winter ends and spring begins, from any sundial ? Was > > this the same day as the official equinox ? > > > These questions are of a religious nature for me. Any assistance would > > be greatly appreciated, or perhaps you could direct me to someone who > > could help. > > > Thank You, in advance ! > > > Signe Best > > > Maybe members of this "Sundial Mailing List" could E-mail direct to Signe, > as well as 'copying' their thoughts to the list for the benefit of others. > > I shall take this opportunity to wish all members a very "Happy New Year". > > Best Regards, > > Douglas Hunt. > > -- > > "MODERN SUNCLOCKS" - 'Human Sundials', using YOUR OWN SHADOW to tell time. > > Looking for a useful, decorative, yet UNIQUE feature ? - you've found it ! > For further details and photographs, see our Website at: www.sunclocks.com > > Mail Address: 1 Love Street, Kilwinning, Ayrshire, Scotland, KA13 7LQ, UK. > Tel & Fax (UK): 01294 552250. International Tel & Fax: + 44 1294 552250. > E-mails to: [EMAIL PROTECTED] OR [EMAIL PROTECTED] > > > > > > - > -
Re: Aries and the rest
Hello Anselmo, I agree with your argument "superstition of astrology", but remember that the zodiacal calendar was very important in the past and not only by astrologers but in all kind of science. In historical vieuw this calendar, and also astrological houses and planetary hours, may not be ignored.in dialing. BTW, a zodiacal calendar is much easier to read on a dial then our Gregorian calendar. Best, Fer. Fer J. de Vries mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/ Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Anselmo Pérez Serrada" <[EMAIL PROTECTED]> To: Sent: Sunday, December 01, 2002 12:08 AM Subject: Aries and the rest > [EMAIL PROTECTED] wrote: > > >I often include Aries and Libra symbols on dials I make. I'm sure it is, or > >used to be, common practice. David Brown 2.05W 52.75N > >- > > > > > > > Dear fellow dialists, > >I've also seen these zodiacal signs in many sundials to mark the > spaces between date-lines. I do not > like this practice because it raises up that (otherwise harmless) > superstition of astrology, but it is still > there in many dials. > > Ah, and being more accurate, the Sun goes through *twelve* signs in a > year (from EclipticalLongitude = 0h-2h > to 22h-24h) but through *thirteen* constellations: the twelve zodiacal > appropriately shifted and Ophiuchus > (The Snake Hunter). Just look it up in a Sky Atlas! > > Best regards, > > Anselmo Perez Serrada > > > - > -
Re: Your new DC macro
Hi Roger, Thanks for combining the seasonal markers and the choice of the fractional hourpoints into one macro. It operates well. Best, Fer. Fer J. de Vries mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/ Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Roger Bailey" <[EMAIL PROTECTED]> To: Sent: Wednesday, November 13, 2002 5:48 PM Subject: RE: Your new DC macro > Hi John and all, > > The revised updated model is attached,"horanalem3filev2B.bas". This one is > based on Fer's latest version and adds a layer with the seasonal markers and > date lines. > > Our perspectives differ on analemmatic sundials. My designs have typically > been large dials in public parks using a person as the gnomon. The gnomon is > wide; the hour points are large. There is no room or need more time points. > Your table top analemmatic dial uses a narrow gnomon and has an accuracy > that demands the finer resolution of more time points. The attached revised > version provides for all these options, fractional hour time points, day > circles and seasonal marker points and lines. > > Thanks for the suggestion. The changes were minor. You should have taken > this on as a homework exercise. > > Cheers, > > Roger Bailey > Walking Shadow Designs > N 51 W 115 > > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of John Carmichael > Sent: November 12, 2002 3:40 PM > To: Roger Bailey ALT.; Roger Bailey > Cc: Sundial List > Subject: Your new DC macro > > > Hi Roger: > > I've been using your new DC macro that includes the Bailey Points. I noticed > however that you modified an older version of Fer's analemmatic macro that > only shows hour point time increments. Your modified DC macro would be much > more useful if you would include time points options for 1/2 hrs, 1/4 hrs, > 1/6 hrs as Fer does in his updated version. (see attachment). > > Just a suggestion! > > John > > -
Question for help
Hi All, On request of Nicola Severino I forward his question for help. Fer. - Dear Friends, I am preparing a catalogue of greek-roman sundials not enclosed in Gibbs (updates!). If you have some informations about new discoveries (also in magazines), please, send me at my e-mail [EMAIL PROTECTED] Thanks Nicola Severino - Fer J. de Vries mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/ Eindhoven, Netherlands lat. 51:30 N long. 5:30 E -
Re: Newspaper Article
John, Nice to see you working on the new analemmatic dial. Fer. Fer J. de Vries mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/ Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "John Carmichael" <[EMAIL PROTECTED]> To: "Sundial List" Sent: Wednesday, October 30, 2002 4:02 PM Subject: Newspaper Article > The Arizona Daily Star reporter who met with the NASS tour group came to my > studio on Monday with a photographer to finish up his interviews. Today his > 1/2 page article appeared in the newspaper. He has several quotes from Fred > Sawyer and also lists all the sundials we saw on our tour. And there are > two good photographs (Fred, I'll send you a copy). > > You can see the article at: > > http://www.azstarnet.com/star/wed/21030FHMAIN.html > > John > > John L. Carmichael Jr. > Sundial Sculptures > 925 E. Foothills Dr. > Tucson Arizona 85718 > USA > > Tel: 520-696-1709 > Email: [EMAIL PROTECTED] > Website: <http://www.sundialsculptures.com> > > > - > -
Re: Digital sundial
Hello Willy, To my opinion the digital sundial by Scharstein is a new concept in modern gnomonics. I also would like to add the holographic sundial, once made in Austria. Who has details? I can't find it back. Perhaps also the dial that uses fiber glass wires to transport the sunspot to any convienient spot could be mentioned, however the baic concept is an equatorial dial.. These kind of dials only could be made thanks to new technology in our times. Some other additions to this article are: The equant dial by Fred Sawyer The dial based on Ptolemaic coordinates by Fred Sawyer The latitude independant dials by Freeman and De Rijk. There will be more and any example will be welcome to comlete the list. Best wishes, Fer. Fer J. de Vries mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/ Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: "Willy Leenders" <[EMAIL PROTECTED]> To: "Sundial List" Sent: Saturday, October 19, 2002 9:15 PM Subject: Digital sundial > In the bulletin of the Britisch Sundial Society, volume 14 (iii) > september 2002, Mrs. Margaret Stanier gives a survey of the > contributions to the art and science of dialing in the twentieth > century. > Two new designs of sundials with the world's first creation in the > Sundial Park at Genk in Flanders (Belgium) are absent in this survey: > > 1. > The conical sundial, the world's first horizontal dial with a conical > gnomon. The two shadows of the cone indicate Babylonian and Italian > hours, respectively. This sundial is an invention of Javier Moreno > Bores, Madrid, Spain. > > 2. > The digital sundial, an intriguing new design that combines the ancient > science of sundials and advances of modern technology with elegant > simplicity. Like a digital clock, the digital sundial displays the > current time using digits without using any form of energy. > > Asked for an explanation Mrs. Stanier answers she agrees that the Bores > design is indeed an interesting new design. > > She dosn't however consider that the digital sundial should be recorded > as an entirely new design. It is a read-out of the conventional vertical > sundial and just a convenient addition to help in the ease and accuracy > of reading a dial face of an ordinary sundial, she sais. > > Can I hear the opinion in this connection of ohter sundialists? > > Willy Leenders > Hasselt, Flanders in Belgium. > > You can find more information about this sundials on the website of > Frans Maes: http://www.biol.rug.nl/maes/genk/welcome-e.htm > > The digital sundial is described by the inventor Daniel Scharstein on > his website at page: http://www.digitalsundial.com/background.html and > in detail at the page of the patent: > http://www.digitalsundial.com/patent.html > > The conical sundial is decribed in "Zonnetijdingen" the periodical of > The Flemish Sundial Society, number 1998 - 09. > It is mentioned in the bulletin of the Britisch Sundial Society No. 97.3 > on page 53 (foto 2) > > > > - -
