RE: A new sundial - type from Bremen!
anything in English on how it works? its beautiful! Dave Scott -Original Message-From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]On Behalf Of [EMAIL PROTECTED]Sent: Thursday, February 28, 2002 12:40 PMTo: sundial@rrz.uni-koeln.deSubject: A new sundial - type from Bremen!Dear friends, may I invite you to have a look at a probably new type of sundial, an analemmatic equatorial sundial with light-pointer, built by my friend Dietrich Ahlers. His HALBE - ACHT - sundial can be seen at the Homepage of Olbers-Planetarium Bremen as sundial of the month March. Either you start at: http://www.hs-bremen.de/planetarium and choose bottom right (sundial of the month) or go directly to: http://planetarium.hs-bremen.de/planetarium/astroinfo/sonnenuhren/ahlers/analem.htm Regards Reinhold Kriegler * ** *** * ** *** Reinhold R. Kriegler Lat: 53° 06' 53'' N Long: 8° 53' 54" E
Helio chronometers
Dear Dialist I'm very interested in finding more information on Helio chronometers and how to make them. can you steer me to more information? David Scott lat. 42:56 N long. 72:40 W Wendell,MA. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Willy Leenders Sent: Thursday, February 21, 2002 8:07 AM To: Sundial List Subject: Sundial in Reims On http://batonline.com/renonciat/instalat/cadran.htm you can see a sundial in Reims (France) This work of art of Christian Renonciat (1991) is situated on the 'Place des Loges Coquault' as a first stage of the 'Voie des Sacres'. The hourlines in the horizontal plane are extended in a vertical plane. There they disperse fanshaped from each other. The hourlines in the vertical plane however must come together in one point, I think. Who can give me more information concerning this sundial. Willy Leenders 50.9 N 5.4 E - -
RE: heliochronometer
fritz, thank you very much. I found, ordered the article and found it in my mail box in a few days. the article was informative. I am a newby Dialist and working on my own Helio chronometer. I have a question about the anelamma, does the shape of the anelamma ,in a Helio chronometer, vary with different locations as the horizontal dials do? Dave Scott lat. 42:56 N long. 72:40 W Wendell,MA. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Fritz Stumpges Sent: Wednesday, March 06, 2002 4:05 PM To: 'sundial@rrz.uni-koeln.de' Subject: RE: heliochronometer Hi Peter, I went to the Sky web page and to the Dec. 94 archives. These must be the articles: "36. Telescope Making - A Precision Sundial of Bronze By Charles F. Avila | December 1994, p. 88 Order Original Issue 37. Telescope Making - Just How Accurate Can a Sundial Be? By Roger W. Sinnott | December 1994, p. 89 Order Original Issue" I was hoping to be able to view them here, but you have to order the entire back issue for $7.95. I actually just ordered it and there was no tax or shipping here in California. Seems great so far! Thanks for this info, Fritz ref. see this to order it: http://skyandtelescope.com/magazinearchive/search/results.asp?start_date_mon th=12&start_date_year=1994&end_date_month=12&end_date_year=1994&pos=26 - -
An easy question
Greetings Dialist I have been slugging away at the third or forth prototype Helio-chronometer and have a problem. It tells time remarkably well but, Am I wrong in expecting the bead of light emanating from the aperture on the alidade to walk horizontally across the anelamma over the course of the day. or does it cross the appropriate date mark on the anelamma at noon? Dave Scott lat. 42:56 N long. 72:40 W Wendell,MA. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Roger Bailey Sent: Thursday, April 18, 2002 11:04 AM To: Sundial Mail List; DeAmicis-Roberts, Mike Subject: Correction Epicycle Hi Mike, I promised to get back to you with some suggestions on corrections for the Sunrise Seasonal Marker that you proposed for your analemmatic sundial. Since this is of general interest, I hope you don't mind me posting this note to the sundial mailing list as well. First let's review the idea. You proposed a marker along the east west axis that could be used to determine the position and time of sunrise and sunset. When I did the calculations to check this proposal, I was surprised to find that indeed there was such point. Lines through this marker and the dates on the zodiac table extended one way shows you the azimuths of theoretical sunrises or sunsets. Extending these lines the other way to the hour ellipse of the dial tells you the times of sunrises or sunsets. This seasonal sunrise marker is a brilliant idea, a great addition to analemmatic sundials. There is a problem. The marker is not a point. All the lines do not go the exact same point but were spread along the axis a short distance. In your case of a large 9 meter or 30 ft diameter dial at your latitude, there is a spread of 15 cm (6 "). The error grows with latitude, reaching unacceptable size at latitudes like mine (51). Helmut Sonderegger suggested minimizing the error by using 20.2 degrees as the reference base for calculations. This works but I preferred to use the solstice as the base as this gave a periodic error. The periodic nature of the error is natural. The straight line approximation of circle should result in circle generated sine type error curves. Then it struck me! Why not correct for this periodic error by using a small circle projected onto the axis? We are in good company here. When Ptolemy needed to correct for orbital anomalies, he used epicycles on his perfect spheres. These epicycles are smaller diameter, or higher frequency cycles on top of the main cycle, sort of like the harmonic terms in a Fourier Series. What I am suggesting is not a true epicycle, a circle on a circle generating "Spirograph" patterns, but it is close enough to use the term. I uses a small spreadsheet to calculate and plot the marker position of the for dates and declinations throughout the year. Have a look at the attachment "Epicycle.pdf". The graph shows as a function of the yearly cycle the usual declination, equation of time, and now the sunrise/set azimuth for your location. The black line on the expanded secondary axis is the position of the seasonal marker throughout the year. It seems to be a perfect sine curve. This is the curve that would be generated by the circle on the right as you go around two rotations per year. The equinoxes are on top, giving the maximum marker position. The solstices are on the bottom showing the minimum position. Your seasonal marker is now a simple circle, 15 cm in diameter with dates marks around the circumference. Estimate the date; drop a perpendicular from the circumference to the axis. This gives you the precise position for the seasonal marker on that date. For general observations you can just sight across the circle. For precise readings, establish a precise line from the zodiac table date to the date from the epicycle on the axis. What a great analogue computer! It is simple to construct and easy to use. The correction epicycle works very well to give you a precise answer for sunset time and location. Now all we have to deal with are those devilish mountains, the Diablo Range, polluting your eastern horizon. Roger Bailey Walking Shadow Designs N 51 W 115 This is the second attempt post this message. The original that had a second attachment of similar size that reviewed the seasonal marker concept must have been stopped by the file size filter. I hope this one gets through. It takes about 6 seconds to transmit on my dial up modem connection. -
RE: An easy question
Hi John, yes it was made to those directions. If i set it up in the morning it will read at approximately the correct date on the anelamma it keeps good time but by the end of the day the date is now near the bottom of the anelamma. i was under the impression that the arch of the apparent motion of the sun was straight and that the angle on the dial face was parallel to that arch and perpendicular to the rotation on the alidade. Dave Scott lat. 42:56 N long. 72:40 W Wendell,MA. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of John Carmichael Sent: Thursday, April 18, 2002 10:22 PM To: sundial@rrz.uni-koeln.de Subject: Re: An easy question Hi Dave Your question could be interpreted in two ways. Roger answered your question assuming that you wanted to know how the sun would move if the alidade was kept stationary with its time pointer over 12 noon. But if you rotate the alidade at any time of the day so that the point of light is on the proper date on the analemma, it will tell the time (I hope you made your alidade moveable so that it can be rotated by hand about the polar axis.) Mayall has a whole chapter dedicated to this type of interactive heliochronometer. 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: "david scott" <[EMAIL PROTECTED]> To: ; "DeAmicis-Roberts, Mike" <[EMAIL PROTECTED]> Sent: Thursday, April 18, 2002 1:56 PM Subject: An easy question > Greetings Dialist > I have been slugging away at the third or forth prototype Helio-chronometer > and have a problem. It tells time remarkably well but, Am I wrong in > expecting the bead of light emanating from the aperture on the alidade to > walk horizontally across the anelamma over the course of the day. or does it > cross the appropriate date mark on the anelamma at noon? > Dave Scott > > > lat. 42:56 N long. 72:40 W > Wendell,MA. > > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of Roger Bailey > Sent: Thursday, April 18, 2002 11:04 AM > To: Sundial Mail List; DeAmicis-Roberts, Mike > Subject: Correction Epicycle > > > Hi Mike, > > I promised to get back to you with some suggestions on corrections for the > Sunrise Seasonal Marker that you proposed for your analemmatic sundial. > Since this is of general interest, I hope you don't mind me posting this > note to the sundial mailing list as well. > > First let's review the idea. You proposed a marker along the east west axis > that could be used to determine the position and time of sunrise and sunset. > When I did the calculations to check this proposal, I was surprised to find > that indeed there was such point. Lines through this marker and the dates on > the zodiac table extended one way shows you the azimuths of theoretical > sunrises or sunsets. Extending these lines the other way to the hour ellipse > of the dial tells you the times of sunrises or sunsets. This seasonal > sunrise marker is a brilliant idea, a great addition to analemmatic > sundials. > > There is a problem. The marker is not a point. All the lines do not go the > exact same point but were spread along the axis a short distance. In your > case of a large 9 meter or 30 ft diameter dial at your latitude, there is a > spread of 15 cm (6 "). The error grows with latitude, reaching unacceptable > size at latitudes like mine (51). Helmut Sonderegger suggested minimizing > the error by using 20.2 degrees as the reference base for calculations. This > works but I preferred to use the solstice as the base as this gave a > periodic error. The periodic nature of the error is natural. The straight > line approximation of circle should result in circle generated sine type > error curves. Then it struck me! Why not correct for this periodic error by > using a small circle projected onto the axis? We are in good company here. > When Ptolemy needed to correct for orbital anomalies, he used epicycles on > his perfect spheres. These epicycles are smaller diameter, or higher > frequency cycles on top of the main cycle, sort of like the harmonic terms > in a Fourier Series. What I am suggesting is not a true epicycle, a circle > on a circle generating "Spirograph" patterns, but it is close enough to use > the term. > > > > I uses a small spreadsheet to calculate and plot the marker position of the > for dates and declinations throughout the year. Have a look at the > attachment "Epicycle.pdf". The graph shows as a function of the yearly cycle > the usual declination, equation of time, and now the sunrise/set azimuth for
RE: An easy question
Here's a jpeg of the drawing, Im leaving town for the next couple of days i will explain it when i get back. the center cylinder is the alidade Dave Scott lat. 42:56 N long. 72:40 W Wendell,MA. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Friday, April 19, 2002 12:20 PM To: sundial@rrz.uni-koeln.de Subject: Re: An easy question David Scott, Could you refer us to a photo of this dial (or attach a small JPEG)? I am having a hard time visualizing it in terms of your question. Bill Gottesman Burlington, VT 44.4674N, 73.2027W - -
My helio
Tony you were kind enough to forward some picts some time in the past. At that time I talk about a design I was working on this is the dial, what do you think? Dave Scott http://dscott.home.igc.org/ -
RE: An easy question
Hi bill I have finally put some picts and drawings together. I found the error that was causing the tracking problem. This is a dial that I hope to produce commercially. The site is just the bare bones I hope there are enough shots of the dial. I am surprised at the accuracy over the short period that I have tested it . Dave Scott -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Friday, April 19, 2002 12:20 PM To: sundial@rrz.uni-koeln.de Subject: Re: An easy question David Scott, Could you refer us to a photo of this dial (or attach a small JPEG)? I am having a hard time visualizing it in terms of your question. Bill Gottesman Burlington, VT 44.4674N, 73.2027W - -
RE: An easy question
Oops, http://dscott.home.igc.org/ -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Dave Bell Sent: Monday, June 17, 2002 9:40 PM To: david scott Cc: sundial@rrz.uni-koeln.de Subject: RE: An easy question And that site is...? On Mon, 17 Jun 2002, david scott wrote: > Hi bill I have finally put some picts and drawings together. I found the > error that was causing the tracking problem. This is a dial that I hope to > produce commercially. The site is just the bare bones I hope there are > enough shots of the dial. I am surprised at the accuracy over the short > period that I have tested it . > Dave Scott > > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] > Sent: Friday, April 19, 2002 12:20 PM > To: sundial@rrz.uni-koeln.de > Subject: Re: An easy question > > David Scott, > Could you refer us to a photo of this dial (or attach a small JPEG)? I am > having a hard time visualizing it in terms of your question. > > Bill Gottesman > Burlington, VT > 44.4674N, 73.2027W > - > > > - > - -
RE: intentional rust finish
COR-TEN was promoted as a material for bridges, but it was discovered after a zillions were built that the welds no longer had the weathering properties of the base metal, and I believe that it was (the weathering properties) some percentage of copper Dave Scott -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Saturday, October 19, 2002 8:00 PM To: sundial@rrz.uni-koeln.de Subject: Re: intentional rust finish In a message dated 2002/10/19 10:06:03, [EMAIL PROTECTED] writes: >Similarly, what about the steels (I don't recall the type >name) used for sculptural works, that quickly develop a dark brown >"rust" layer, which supposedly protects the underlying steel (just as >aluminum, titanium, and stainless steels do) from further progression? Possibly COR-TEN? (Sometimes spelled corten or cor ten.) It was used in WWII to make amphibious vehicles. We had tons of it left over from WWII in a factory at which I once worked. It sat in the weather but never seemed to acquire deep pitting. John Bercovitz Rust never sleeps. - -
RE: flaking sundial
There is a product named West Systems epoxy (that was developed for laminating wood for large hi tech wind mill blades) that is extremely viscous. I have also heard of carpenters using an ordinary vacuum cleaner and a plastic bag for laminating jobs. It would important to draw off any air pockets and seal the stone. But having said that I also remember advice against painting brick because it needs to "breath" and not trap moisture that would cause it to spall. Dave Scott -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Monday, November 25, 2002 2:14 AM To: sundial@rrz.uni-koeln.de Subject: flaking sundial Object - a vertial south sundial of 1700, in a sandstone type of material. It is 24 inches square. with carved numerials and hour lines. Went tapped, an area about 12 inches diameter sounds hollow where a thin surface area is detached from the backing of the 1.5 inch thich dial. Does anyone know how to secure this loose area to the sound stonework behind ?. I quesstimate this loose area is about one eighth of an inch thick. Perhaps maybe drilling a tiny hole, and injecting some bonding agent. It is planned to do this work next year in warm weather. Your help much appreciated. David. ___ Freeserve AnyTime, only £13.99 per month with one month's FREE trial! For more information visit http://www.freeserve.com/time/ or call free on 0800 970 8890 - -
RE: More on etching
If you wouldn't mind please include me in this mailing Thanks, Dave Scott -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Friday, April 11, 2003 4:42 AM To: Sundial Mail List Subject: More on etching Fellow shadow watchers, Further to my recent email following Peter Mayer's resurrection of my previous comments on the etching process I've located the jpegs of my home-made etching machine distributed some years ago to my own mailing list of those who receive my pics on 'making metal sundials'. If any recent SML members would like to see these please let me know and I'll do a group mailing together with a jpeg of my revised holder for plates during etching. At the same time the revised plate holder pic will be sent to my jpeg mailing list without members making a special request for it. Anyone wishing to be added to/removed from my jpeg mailing list please let me know. Have fun! Tony Moss - -
RE: Spare copies of a book with pop-out models to make
I'd like on peter who do you wand to do this? I live in the us David Scott -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of peter ransom Sent: Wednesday, January 01, 2003 6:31 PM To: sundial@rrz.uni-koeln.de Subject: Spare copies of a book with pop-out models to make Today I was fortunate to liberate (at a discounted price of £2 each) 10 copies of the book TIME by Silke Ackermann and Paul Buck published by the British Museum at £8.99. This is an A4 book with 32 pages plus 4 pages of press-out-and-make models of a universal equatorial dial (there are two separate models - one for each hemisphere), a nocturnal (again, one for each hemisphere) and a perpetual calendar. It even comes with a small compass on the front for your equatorial dial! I am happy to send one copy to the first 11 people who reply (off list) and request my address so they can send me £3 (UK only - cash or cheque) or 10 Euros (or a £5 note) (Europe) or $8 (rest of world) in used notes to avoid horrendous bank charges. The difference in price is due to the cost of the book plus postage. People in the UK may find the book for sale at The Works (a publishing outlet shop) if there is one handy. Happy New Year to everyone. Peter Ransom (Hampshire, GB) ps Quite an auspicious day as my daughter also got engaged today! _ MSN 8: advanced junk mail protection and 2 months FREE*. http://join.msn.com/?page=features/junkmail - -
Me too, Please
Fritz, Would mind sending those images to me also? Thanks Dave Scott David Scott [EMAIL PROTECTED] 42.59 N 72.39 W
RE: Sundial Cupolas
I hope it's ok to slip this into the conversation about vertical dials. Last year I finished building a medium sized CNC router table, it has a carving area of 3'X 4'. I made it especially for making vertical sundials. Even though it looks like something that Fred Flintstone built ,It will cut aluminum and brass but only reluctantly; I'm using a 3 ? horse wood router that really doesn't have the bearings to push through metal for very long. I have experimented with different materials and like a material (PVC) that is made for exterior trim ( it looks like painted wood) and comes in boards and sheets up to 4'X 10', I have made several dials from Pine and then painted them. I use the Sonne program to generate the Analemma and hour lines in dxf form and old versions of AutoCAD and Corel to add framing and text. I am offering this information for two reasons . The latest thread about vertical dial and dials on cupolas reminded me that there might be members that were interested in using me as a resource in construction low cost vertical dials. Secondly, I was invited to do a write-up or presentation to the compendium on building low cost cnc machines for dialing. I am willing to share what I know. But the task of putting together a formal authoritative presentation about something I really don't know much about is out of the question. What I have considered is a collaboration with some one or a group from the dialing list that is interested in building their own and writing about it. There's is a picture of the machine and some of my dials on my web site. Spend a little time on the site and you'll understand why I don't want to write the presentation. I don't write! www.scottdesignsundials.com there is a link to a Sign site with lots of signs carved in oak which is turning out to be my bread and butter. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Andrew James Sent: Tuesday, March 22, 2005 6:18 AM To: John Carmichael; Sundial List Subject: RE: Sundial Cupolas There is a modern (1990s?) cupola with a South sundial on it at South Warnborough, in Hampshire. I believe the owner originally intended to put a clock in as well but am not sure whether he ever did. I can think of a few other similar arrangements around the country - for example I think Goodwood House has a large 18th century sundial and clock in such a position. However I can't recall seeing a proper set of four dials so arranged. Do you count the Gate of Honour at Gonville and Caius College, Cambridge, with its six sundials, as a cupola? See http://www.cai.cam.ac.uk/map/cCourt.php for a good view. If you ground the weathervane, bear in mind that lightning conductors should be substantial, avoid sharp bends, and go to a very good earth indeed. Andrew James -Original Message- From: John Carmichael [mailto:[EMAIL PROTECTED] Sent: 19 March 2005 17:56 To: Sundial List Subject: Sundial Cupolas Hello All: I'm considering building or buying a four-sided painted wood cupola with a copper roof for the roof of a home. I'd like to put a sundial on each face of the cupola and then a neat weathervane on top. Have any of you ever seen a cupola or "clock tower" with sundials instead of clocks? John p.s. Do you think the copper weathervane will act like a lightning rod? Maybe it should be grounded? PRI Limited, PRI House, Moorside Road Winchester, Hampshire SO23 7RX United Kingdom Tel: +44 (0) 1962 840048 Fax: +44 (0) 1962 841046 www.pri.co.uk The Intelligent Metering Company This correspondence is confidential and is solely for the intended recipient(s). If you are not the intended recipient, you must not use, disclose, copy, distribute or retain this message or any part of it. If you are not the intended recipient please delete this correspondence from your system and notify the sender immediately. This message has been scanned for viruses by MailControl - -
