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 Attachment converted: Macintosh HD:vagnozzi1.jpg (JPEG/JVWR) (0008F30F)
Re: Construction Project
Hi Tony et al, Yes, I did some experimental dials in anodised aluminium a few years ago, following your excellent advice. I haven't had the actual dials outside all the time, but I have had an Equation of Time plaque made by the same method on the south wall of my house (in the full glare of English sunshine!) for four years. It's silver (natural) anodised with black lines and lettering. As far as I can tell by eye, it's suffered no degradation at all. Although the black-on-silver is close to perfect for shadow visibility, my customers are a very traditional bunch and prefer brass/bronze, so there's not much call for the anodisation. Regards, John -- > from:[EMAIL PROTECTED] > date:Mon, 07 Jul 2003 15:46:22 > to: sundial@rrz.uni-koeln.de > subject: Re: Construction Project > > Rudolf Hooijenga asked: > > >Hello Tony and other readers of the list, > >either I was not subscribed then, or I skipped it because I was not going to > >work on aluminium, > >but I would be really interested in a repeat now. Would you please? > > Hi Rudolf, > As it is a text only message I'll risk boring everyone by repeating > my original postings some of which were in response to other queries. I have > to say that while many years ago I did dozens of projects in creative > anodising none of them ever included an actual sundial. John Davis on the > other hand has experimented with this and might wish to comment on its > potential in particular durability and resistance to ultra violet light which > was queried last time around. > > Best wishes > > Tony M. > Dr J R Davis Flowton Dials N52d 08m: E1d 05m -
Re: duomo di Milano
The volume on the sundial in the Cathedral of Milan, very complete and with a lot of technical and historical news, described by Giovanni Barbi and published in 1976, is now out of print. A small volume, with a short description of the sundial, has been published in 2001 and is in sale in the cathedral. The cost is 5 euro (around 5 US $) Probably it can be asked also at the address [EMAIL PROTECTED] Publisher " VENERANDA FABBRICA DEL DUOMO" - 2001 Carlo Ferrari dal Passano - Carlo Monti - Luigi Mussio La meridiana solare del Duomo di Milano - 25 pag. - 10 photos Some data on the sundial. Since the Milan cathedral has the direction East-West (entry in the West side), the meridian line crosses the naves of the church and it is traced at few meters from the principal entry. Design and construction: Giovanni Angelo De Cesaris (astronomer of the Observatory of Brera) -1786 Height of the Hole 23.82 m Diameter of the hole 25.2 mm (1/945 of the height) Since the meridian line is longer than the width of the cathedral it is developed on the floor for 53.85m and then it "climbs" on the North wall for around 2.90 m The dimensions of the image of the Sun change from around 0.26 x 0.26m on summer Solstice to around 1.27 x 0.55m on November 20. The speed of the movement of the image on the floor is between 4 mm/sec (winter) and 1.7 mm (summer) The sundial has been verified and restored in 1827, in 1921 and in 1976, Originally, plates of marble with the zodiacal signs were present but they have been removed in the 1827 restauration: only the plate of the Capricorn sign remains. Some sundials in other Italian churches (as. that in the church of S. Petronio in Bologna - see Heilbron volume) were built mainly as astronomical instruments to determine the ecliptic inclination, the dates of the equinoxes, etc. On the contrary, the sundial in Milan was built as "official clock" to determine the instant of the noon with which to regulate the city clocks. On October 23rd 1786 the authority emanated a decree in which it was established that from December 1st 1786 in Lombardy (the italian region in which Milan is) the ancient system of the "italic hours" had to have abandoned and replaced from the system of the "French hours" (the modern hours with the beginning of the day at midnight) In 1786, Lombardy belonged, from 1713, to the Austrian Empire. Gianni Ferrari 44° 39' N 10° 55' E Mailto : [EMAIL PROTECTED] -
Re: Construction Project
Rudolf Hooijenga asked: >Hello Tony and other readers of the list, >either I was not subscribed then, or I skipped it because I was not going to >work on aluminium, >but I would be really interested in a repeat now. Would you please? Hi Rudolf, As it is a text only message I'll risk boring everyone by repeating my original postings some of which were in response to other queries. I have to say that while many years ago I did dozens of projects in creative anodising none of them ever included an actual sundial. John Davis on the other hand has experimented with this and might wish to comment on its potential in particular durability and resistance to ultra violet light which was queried last time around. Best wishes Tony M. ** FIRST POSTING Subject: More on Metal Sundial Processes Sent:11/11/99 12:30 am To: Sundial Mail List, sundial@rrz.uni-koeln.de Fellow Shadow Watchers Continuing my occasional series of practical approaches for metal sundials here is a distillation of my personal notes on anodising aluminium prepared over many years of practical experience at workshop level. Aluminium has a normally dull and soft surface but anodising can transform this into beautiful multi colours with a weatherproof surface hard enough to resist all but the sharpest instruments. Interested? Then read on! ** Anodising Aluminium in the Home Workshop 1. You will need a large acid-proof plastic container. Any strong polyethylene bucket or tank will do into which your workpiece will fit with a three inch gap all round. Alternatively I made purpose built tanks out of marine plywood covered with a liquid-proof layer of glass-fibre resin and surfacing tissue. After years of use these tanks are still in good working order. Just one very large tank will serve but of course this will need a lot of electrolyte. 2. You must have good ventilation as the fine bubbles of gas which rise to the surface produce an weak acidic mist which is barely detectable - and then one day you discover you have lost your sense of smell! There is also the possible risk of male impotence which is why this was once known as 'etcher's disease'. You have been warned! VENTILATE! I have three healthy sons but that was before I began anodising! 3. You can anodise with low voltage AC or DC but if you use AC the Cathode¹ mentioned below MUST be of lead not aluminium. 4 The cathode (negative connection) can be formed from a sheet of aluminium bent to fit around the interior walls of your tank as a loose liner¹. Leave a projection tab to bend over the edge of the tank with a terminal to which the negative wire is connected if you are using DC .If your power supply is AC then the cathode must be sheet lead. 5. Part-fill the tank with electrolye made by adding one part of concentrated sulphuric acid to nine parts of water. Wearing goggles and gloves pour the acid SLOWLY down the side of the tank into the water. NOT the other way around. Pause if too much heat is generated. 6. Experiment with a piece of aluminium plate about 3² square to get the idea. Drill a hole in one corner and attach a pure aluminium wire by clinching with pliers to ensure a sound contact. 1/16² aluminium gas welding rods are perfect for this job. If contact with the wire is loose then the non-conducting anodic film may form in the joint and this will stop the process. Design items to allow appropriate wire attachment - leave a cut-off 'tab' or drill a hole in the base into which a filed taper can be wrung/seized¹ tightly. Hollow items can be held on an expanding zig-zag made to spring open into the inside. etc. etc. 7. Holding the object by the wire dip it into a strong solution of caustic soda for a few seconds until it fizzes to remove natural oxides and grease. Rinse in clean water. Eye hazard - Wear goggles for this operation. 8. Suspend in the anodising tank supported from some kind of busbar. I use a square brass bar over the tank drilled at intervals with screws to clamp the wire into the holes and ensure a good contact. 9. Connect the positive lead of your power supply to the workpiece via the busbar and the negative lead to the Cathode lining of the tank. 10. Set the voltage to about 16v and in a few minutes fine bubbles of oxygen should rise from the workpiece. The oxygen produced by the electrolysis of the water in the electrolyte combines with the aluminium at the surface to produce crystal-clear aluminium oxide (grindstones are made from it!). It is thought that the oxide is produced is microscopic tubes¹ rising from the surface rather like a honeycomb. Electrical contact is maintained through the tubes and new oxide continues to form at the base thickening the film. After about 20/30 minutes you can switch off the current, remove and rinse in CLEAN water. The aluminium will have a
RE: Motto "T'is nothing but a magic shadow show"
Hola Anselmo: cordial saludo, desde hace tiempo he visto tus importantes y frecuentes contribuciones en este correo, los relojes solares para mi son algo muy interesante. Alguna vez me respondiste una pregunta que te hice. Ahora te escribo porque quisiera saber donde vives y que haces, cual es tu profesion y como es el curso que dictas de relojes solares, igualmente si tienes una pagina internet. Amigo Luis C Cadavid 6 16 N 75 34 W Medellin Colombia -
Persian, Arabic and Kufic
Dear dialists, And just by sake of curiosity: does anybody have the original arabic quotation written in kufic symbols? (I know that Omar Khayyam was Iranian but, to my knowledge he used to write in arabic, didn't he?) No, he wrote in Persian. Persian, Perse, Pharasee, Farsee, Farsi... are all variants of the same word. "Iran", which is related to "Aryan" was adopted as the name of the country starting in 1936 to replace "Persia" for reasons too complicated to to into, partly as a result as an attempt to curry favor with Nazi Germany but also due to reasons of internal ethnic inclusiveness. Persian/Farsi is written using the Arabic alphabet, but the Persian (Farisi) language is completely unrelated to Arabic. Actually, it's an Indo- European language, and as such is a distant cousin of our more familiar romance and germanic groups. Arabic is a Semitic language and has a completely different structure from Farsi. So if you can't understand Arabic or Persian and see a written sample, they look pretty much the same, just as English and Finnish might look the same to a Chinese reader looking at printed material. Kufic is a type of stylized arabic writing that was in vogue during the 8th through the 10th century. It uses an angular, non-slanted block style particularly suitable for inscriptions in stone, as opposed to the traditional flowing cursive arabic script normally written with a pen . Saying "...written in Kufic symbols" is like saying "...written in helvetica sans serif type" So what you want is the original Persian quotation written in Arabic script or Arabic letters. Jack -
Re: Stained Glass dials page
A few more images added, and a bit of reshuffling, to better group them... > Latest results are at: > >http://www.AdvanceAssociates.com/Sundials (select Stained Glass) or: > >http://www.AdvanceAssociates.com/Sundials/Stained_Glass or: > >http://tinyurl.com/frf4 > > Dave > 37.28N 121.97W -
Re: Construction Project
Hello Tony and other readers of the list, either I was not subscribed then, or I skipped it because I was not going to work on aluminium, but I would be really interested in a repeat now. Would you please? Thank you, Rudolf 52-30N 4-40E - Original Message - From: <[EMAIL PROTECTED]> (...) > > Aluminium doesn't engrave very well so you might consider producing your > scales etc. by anodising. (...) > I published detailed notes on the SML on the practicalities of this > process some years ago but can repeat on request. -
Re: Stained Glass Sundial Photos
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 > > > > - -
