Re: Re Man wants heliochronometer
Dear Frank, As ever, you prompt several interesting trains of thought... > In fact any run-of-the-mill astro-navigator > with a merely passable sextant could at > least manage an accuracy of a minute of > arc... I have never used a sextant but I have heard this arc-minute figure so many times I am willing to believe it! > ...or four seconds of time. Careful here! Most of the year the sun goes round in a small circle so an arc-minute change in position takes longer than four seconds. Also, I am not sure what angle you are measuring? You can't mean the solar altitude. That doesn't change anything like an arc-minute in 4s where I live! > For a really accurate dial could the > east or west limb of the sun be > projected and utilised? Well you can project the whole solar disc using a continental camera obscura sundial and thereby see both east and west limbs of the sun. I have observed transit at the Basilica di S. Maria degli Angeli in Rome many times, sometimes with enthusiasic Italian diallists adding to the fun! Each diallist shouts "Ora" [Now] at what he perceives to be the critical moment and the chorus lasts two or three seconds, so that's an observational error for a start. The very first time I did this, I noted the time of the middle "Ora" on my radio-controlled watch and did the reductions. This includes allowing for the difference between UTC and UT1. It was pretty good, the error was about 3.5 seconds. Alas, I have done this many times since and noted errors of up to 10 seconds. There are too many things to go wrong... Mario Catamo says that you get a build-up of muck on one side of the hole which shifts the apparent centre. There would need to be a lot of muck to account for 10 seconds though! I believe the line isn't quite north-south but since I always go at much the same time of year the error should be consistent! That said, I think 10 seconds is pretty good. Frank Frank King Cambridge, U.K. --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re Man wants heliochronometer
Greetings, fellow dialists, Tom Kreyche wrote: "With my Wild Heerbrugg T3000 Digital Theodolite equiped with a Roelofs Solar Prism I can achieve a few seconds accuracy for solar observations by taking a great deal of care with the sophisticated leveling system, assuming the base is stable, the temperature doesn't change, there is no wind and you don't touch the instrument. No doubt an experienced surveyor with astronomical observation experience can do better, or perhaps an experienced navigator with a good sextant." In fact any run-of-the-mill astro-navigator with a merely passable sextant could at least manage an accuracy of a minute of arc, or four seconds of time. Accuracy down to a tenth of a minute is quite possible. Would that be partly because sextant observations use the edge (limb) of the sun and not the less precise whole disc? Of course, the sea horizon, with a small correction, gives you a perfect level, too. For a really accurate dial could the east or west limb of the sun be projected and utilised? Frank 55N 1W --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Man Wants heliochronometer
John, He wants a sundial that can tell the time to “THE SECOND”. He’ll be lucky! Does he realise that the difference per second will be 0.0042 of a degree. So you will be marking out the 24 hour time scale into 86,400 divisions. I have quite a few heliochronometers and the best one I have (that is still available) is a Gunning. Despite the claims, I think the Pilkington Gibbs heliochronometer is only accurate to 2 minutes, - it is only marked in 2 minute divisions and the cam is probably worn after 100 years! The P&G Sol is marked to 1 minute and probably can (just) if you can find one. We think only about 50 were ever made, and I only know of 9 – do let me know if you have one. My Aten is an early one that doesn’t have the later vernier scale. I have a Silas Higgon (Bernhard type), but that’s only marked in 5 minute divisions. My Schmoyer Sunquest is a nice instrument, but is really a compromise heliochronometer. The Gunning IS accurate to a minute – you can’t really see the divisions smaller than that. That said, you really do have to know what you are doing to set it up: accurately orientated – flat and level in all directions and set to exactly the correct latitude. I found that the latitude scale as manufactured wasn’t accurate enough. Mike Shaw 53º 22' North 03º 02' West www.wiz.to/sundials--- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Man Wants heliochronometer
Hi Kevin at all, If you want really high resolution from a small solar timekeeper, try a dipleidoscope! They can resolve down to a second or two. Regards, John Dr J Davis Flowton Dials From: Kevin Karney kar...@me.com These dials are latitude adjustable, correctable for longitude and summer time hours. They are meant for permanent installation so no do have levelling screws or compass. There is no my knowledge any heliochronometer that will tell the time better than 30 seconds accuracy, but I would love to be corrected on that! Best regards Kevin--- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Man Wants heliochronometer
Good Afternoon Always nice to know that David is still remembered for his beautiful instrument. I had high hopes of continuing the building of the Aten Heliochronometer after his death but as I am no machinist, I was unable to find anyone to make the dial at a reasonable cost. My sincere apologies for any confusion caused by the continuing existence of the website. As always in life, many other more pressing matters have had to be dealt with. This conversation serves as a reminder that I need to look in to what needs to be done. I continue to listen and learn through your conversations. Sincerely J Gard Sent from Windows Mail From: Tom Kreyche Sent: Thursday, May 23, 2013 10:07 AM To: sundial@uni-koeln.de I wonder if there is an upper weight limit on "portable" sundials. Back in the old days of computers, there was a "luggable" category - maybe we should revive this as a sundial classification. Even with substantial material cutouts, a 30-40 cm brass dial would be a candidate. With my Wild Heerbrugg T3000 Digital Theodolite equiped with a Roelofs Solar Prism I can achieve a few seconds accuracy for solar observations by taking a great deal of care with the sophisticated leveling system, assuming the base is stable, the temperature doesn't change, there is no wind and you don't touch the instrument. No doubt an experienced surveyor with astronomical osbservation experience can do better, or perhaps an experienced navigator with a good sextant. ...Tom Kreyche From: "Kevin Karney" To: "John Carmichael" Cc: "Sundial Mailing List" Sent: Thursday, May 23, 2013 9:33:46 AM Subject: Re: Man Wants heliochronometer That is an Aten Sundial made by J. D. Gard http://atensundials.com Sadly Mr Gard has died and I do not know if the business has been continued by his wife. The website invites e-mail enquiries and no longer gives prices. These dials are latitude adjustable, correctable for longitude and summer time hours. They are meant for permanent installation so no do have levelling screws or compass. There is no my knowledge any heliochronometer that will tell the time better than 30 seconds accuracy, but I would love to be corrected on that! Best regards Kevin On 23 May 2013, at 16:26, John Carmichael wrote: This man wrote to me wanting to order a particular type of heliochronometer. I told him that I do not manufacture what he wants and that I would forward his resquest to The Sundial List. Perhaps one of you can sell him what he wants. See his description and photo below. Thx John From: ja.humb...@bluewin.ch [mailto:ja.humb...@bluewin.ch] Sent: Wednesday, May 22, 2013 4:11 PM To: jlcarmich...@comcast.net Subject: Accurate heliochronometer Hello, You do what I like! I am looking for a very accurate portable heliochronometer that can tell the time to the second in brass, no wood you know why! Shape more or less like picture, but with large Vernier scale, graduated latitude dial in half degrees around ca lat. 30 and 60, size 30-40 cm dial ring diameter, base plate with leveling screw for horizontal setting, compass in the base, precise and large analemma for equation of time, engraved hours and minutes on the ring if possible, motto and figurine on it. My position : lat. 46°31 minute N/long. 6°38 minute 50 sec. E. How about the price ? Best regards, Jacques Humbert Av. de Rumine 11 1005 Lausanne/CH atenII --- https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial--- https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Man Wants heliochronometer
I wonder if there is an upper weight limit on "portable" sundials. Back in the old days of computers, there was a "luggable" category - maybe we should revive this as a sundial classification. Even with substantial material cutouts, a 30-40 cm brass dial would be a candidate. With m y Wild Heerbrugg T3000 Digital Theodolite equiped with a Roelofs Solar Prism I can achieve a few seconds accuracy for solar observations by taking a great deal of care with the sophisticated leveling system, assuming the base is stable, the temperature doesn't change, there is no wind and you don't touch the instrument . No doubt an experienced surveyor with astronomical osbservation experience can do better, or perhaps an experienced navigator with a good sextant. ...Tom Kreyche - Original Message - From: "Kevin Karney" To: "John Carmichael" Cc: "Sundial Mailing List" Sent: Thursday, May 23, 2013 9:33:46 AM Subject: Re: Man Wants heliochronometer That is an Aten Sundial made by J. D. Gard http://atensundials.com Sadly Mr Gard has died and I do not know if the business has been continued by his wife. The website invites e-mail enquiries and no longer gives prices. These dials are latitude adjustable, correctable for longitude and summer time hours. They are meant for permanent installation so no do have levelling screws or compass. There is no my knowledge any heliochronometer that will tell the time better than 30 seconds accuracy, but I would love to be corrected on that! Best regards Kevin On 23 May 2013, at 16:26, John Carmichael < jlcarmich...@comcast.net > wrote: This man wrote to me wanting to order a particular type of heliochronometer. I told him that I do not manufacture what he wants and that I would forward his resquest to The Sundial List. Perhaps one of you can sell him what he wants. See his description and photo below. Thx John From: ja.humb...@bluewin.ch [mailto:ja.humbert@ bluewin.ch ] Sent : Wednesday, May 22, 2013 4:11 PM To: jlcarmich...@comcast.net Subject: Accurate heliochronometer Hello, You do what I like! I am looking for a very accurate portable heliochronometer that can tell the time to the second in brass, no wood you know why! Shape more or less like picture, but with large Vernier scale, graduated latitude dial in half degrees around ca lat. 30 and 60, size 30-40 cm dial ring diameter, base plate with leveling screw for horizontal setting, compass in the base, precise and large analemma for equation of time, engraved hours and minutes on the ring if possible, motto and figurine on it. My position : lat. 46°31 minute N/long. 6°38 minute 50 sec. E. How about the price ? Best regards, Jacques Humbert Av. de Rumine 11 1005 Lausanne/CH atenII--- https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Man Wants heliochronometer
That is an Aten Sundial made by J. D. Gard http://atensundials.com Sadly Mr Gard has died and I do not know if the business has been continued by his wife. The website invites e-mail enquiries and no longer gives prices. These dials are latitude adjustable, correctable for longitude and summer time hours. They are meant for permanent installation so no do have levelling screws or compass. There is no my knowledge any heliochronometer that will tell the time better than 30 seconds accuracy, but I would love to be corrected on that! Best regards Kevin On 23 May 2013, at 16:26, John Carmichael wrote: > This man wrote to me wanting to order a particular type of heliochronometer. > I told him that I do not manufacture what he wants and that I would forward > his resquest to The Sundial List. Perhaps one of you can sell him what he > wants. See his description and photo below. > > Thx > > John > > > From: ja.humb...@bluewin.ch [mailto:ja.humb...@bluewin.ch] > Sent: Wednesday, May 22, 2013 4:11 PM > To: jlcarmich...@comcast.net > Subject: Accurate heliochronometer > > Hello, > You do what I like! > I am looking for a very accurate portable heliochronometer that can tell the > time to the second in brass, no wood you know why! Shape more or less like > picture, but with large Vernier scale, graduated latitude dial in half > degrees around ca lat. 30 and 60, size 30-40 cm dial ring diameter, base > plate with leveling screw for horizontal setting, compass in the base, > precise and large analemma for equation of time, engraved hours and minutes > on the ring if possible, motto and figurine on it. My position : lat. 46°31 > minute N/long. 6°38 minute 50 sec. E. > How about the price ? > Best regards, > Jacques Humbert > Av. de Rumine 11 > 1005 Lausanne/CH > > --- > https://lists.uni-koeln.de/mailman/listinfo/sundial > --- https://lists.uni-koeln.de/mailman/listinfo/sundial
FW: Man Wants heliochronometer
This man wrote to me wanting to order a particular type of heliochronometer. I told him that I do not manufacture what he wants and that I would forward his resquest to The Sundial List. Perhaps one of you can sell him what he wants. See his description and photo below. Thx John From: ja.humb...@bluewin.ch [mailto:ja.humb...@bluewin.ch] Sent: Wednesday, May 22, 2013 4:11 PM To: jlcarmich...@comcast.net Subject: Accurate heliochronometer Hello, You do what I like! I am looking for a very accurate portable heliochronometer that can tell the time to the second in brass, no wood you know why! Shape more or less like picture, but with large Vernier scale, graduated latitude dial in half degrees around ca lat. 30 and 60, size 30-40 cm dial ring diameter, base plate with leveling screw for horizontal setting, compass in the base, precise and large analemma for equation of time, engraved hours and minutes on the ring if possible, motto and figurine on it. My position : lat. 46°31 minute N/long. 6°38 minute 50 sec. E. How about the price ? Best regards, Jacques Humbert Av. de Rumine 11 1005 Lausanne/CH atenII <http://atensundials.com/images/at2big.jpg> --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: eBay : ANTIQUE HELIOCHRONOMETER BRONZE SUN DIAL SCIENTIFIC INSTRUMENT
I can add to Geoff's post that he has his own website at: www.gunningsundials.co.uk and Sundials on the Internet has other details: www.sundials.co.uk/sunfair/gunning-sundials/ Best wishes, Doug On 5 Sep 2012, at 19:42, Geoffrey Thurston wrote: > Folks, > > It seems that these dials are still available from: > > http://www.draysonbeckett.co.uk/gunning.sundials/index.html > > Best Wishes, > > Geoff > > -Original Message- > From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Jackie > Jones > Sent: 05 September 2012 17:46 > To: 'Douglas Bateman'; 'Kevin Karney' > Cc: sundial@uni-koeln.de > Subject: RE: eBay : ANTIQUE HELIOCHRONOMETER BRONZE SUN DIAL SCIENTIFIC > INSTRUMENT > > John Gunning of Petersfield is still a member of the BSS. > Best wishes, > Jackie Jones, BSS membership secretary > > -Original Message- > From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Douglas > Bateman > Sent: 05 September 2012 14:34 > To: Kevin Karney > Cc: sundial@uni-koeln.de > Subject: Re: eBay : ANTIQUE HELIOCHRONOMETER BRONZE SUN DIAL SCIENTIFIC > INSTRUMENT > > Not antique! Im fairly certain it was made by J P Gunning, of Petersfield, > Hampshire (as on the dial with initials JPG). He may still be a member of > the British Sundial Society. > > Otherwise a perfectly serviceable instrument. > > Regards, Doug > > On 5 Sep 2012, at 12:05, Kevin Karney wrote: > >> I came across the attached on eBay >> >> > http://www.ebay.co.uk/itm/ws/eBayISAPI.dll?ViewItem&item=320976724417&ssPage > Name=ADME:B:SS:GB:1123 >> >> anyone interested? >> >> Kevin Karney >> >> --- >> https://lists.uni-koeln.de/mailman/listinfo/sundial >> > > --- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > --- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > > > - > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2012.0.2197 / Virus Database: 2437/5249 - Release Date: 09/04/12 > --- https://lists.uni-koeln.de/mailman/listinfo/sundial
RE: eBay : ANTIQUE HELIOCHRONOMETER BRONZE SUN DIAL SCIENTIFIC INSTRUMENT
Folks, It seems that these dials are still available from: http://www.draysonbeckett.co.uk/gunning.sundials/index.html Best Wishes, Geoff -Original Message- From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Jackie Jones Sent: 05 September 2012 17:46 To: 'Douglas Bateman'; 'Kevin Karney' Cc: sundial@uni-koeln.de Subject: RE: eBay : ANTIQUE HELIOCHRONOMETER BRONZE SUN DIAL SCIENTIFIC INSTRUMENT John Gunning of Petersfield is still a member of the BSS. Best wishes, Jackie Jones, BSS membership secretary -Original Message- From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Douglas Bateman Sent: 05 September 2012 14:34 To: Kevin Karney Cc: sundial@uni-koeln.de Subject: Re: eBay : ANTIQUE HELIOCHRONOMETER BRONZE SUN DIAL SCIENTIFIC INSTRUMENT Not antique! Im fairly certain it was made by J P Gunning, of Petersfield, Hampshire (as on the dial with initials JPG). He may still be a member of the British Sundial Society. Otherwise a perfectly serviceable instrument. Regards, Doug On 5 Sep 2012, at 12:05, Kevin Karney wrote: > I came across the attached on eBay > > http://www.ebay.co.uk/itm/ws/eBayISAPI.dll?ViewItem&item=320976724417&ssPage Name=ADME:B:SS:GB:1123 > > anyone interested? > > Kevin Karney > > --- > https://lists.uni-koeln.de/mailman/listinfo/sundial > --- https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.2197 / Virus Database: 2437/5249 - Release Date: 09/04/12 --- https://lists.uni-koeln.de/mailman/listinfo/sundial
RE: eBay : ANTIQUE HELIOCHRONOMETER BRONZE SUN DIAL SCIENTIFIC INSTRUMENT
John Gunning of Petersfield is still a member of the BSS. Best wishes, Jackie Jones, BSS membership secretary -Original Message- From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Douglas Bateman Sent: 05 September 2012 14:34 To: Kevin Karney Cc: sundial@uni-koeln.de Subject: Re: eBay : ANTIQUE HELIOCHRONOMETER BRONZE SUN DIAL SCIENTIFIC INSTRUMENT Not antique! Im fairly certain it was made by J P Gunning, of Petersfield, Hampshire (as on the dial with initials JPG). He may still be a member of the British Sundial Society. Otherwise a perfectly serviceable instrument. Regards, Doug On 5 Sep 2012, at 12:05, Kevin Karney wrote: > I came across the attached on eBay > > http://www.ebay.co.uk/itm/ws/eBayISAPI.dll?ViewItem&item=320976724417&ssPage Name=ADME:B:SS:GB:1123 > > anyone interested? > > Kevin Karney > > --- > https://lists.uni-koeln.de/mailman/listinfo/sundial > --- https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: eBay : ANTIQUE HELIOCHRONOMETER BRONZE SUN DIAL SCIENTIFIC INSTRUMENT
I have told the seller that it is neither antique nor bronze, but he has ignored the information. Mike Shaw 53º 22' North 03º 02' West www.wiz.to/sundials --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: eBay : ANTIQUE HELIOCHRONOMETER BRONZE SUN DIAL SCIENTIFIC INSTRUMENT
Not antique! Im fairly certain it was made by J P Gunning, of Petersfield, Hampshire (as on the dial with initials JPG). He may still be a member of the British Sundial Society. Otherwise a perfectly serviceable instrument. Regards, Doug On 5 Sep 2012, at 12:05, Kevin Karney wrote: > I came across the attached on eBay > > http://www.ebay.co.uk/itm/ws/eBayISAPI.dll?ViewItem&item=320976724417&ssPageName=ADME:B:SS:GB:1123 > > anyone interested? > > Kevin Karney > > --- > https://lists.uni-koeln.de/mailman/listinfo/sundial > --- https://lists.uni-koeln.de/mailman/listinfo/sundial
eBay : ANTIQUE HELIOCHRONOMETER BRONZE SUN DIAL SCIENTIFIC INSTRUMENT
I came across the attached on eBay http://www.ebay.co.uk/itm/ws/eBayISAPI.dll?ViewItem&item=320976724417&ssPageName=ADME:B:SS:GB:1123 anyone interested? Kevin Karney --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Heliochronometer Card Dials
Sunny Day! This isn't a card dial but it is made of paper and might just get you to lunch on time. It could work for the application that Gerard Hughes spoke about. It can be adjusted for latitude, longitude and the equation of time. Unfortunately it will only work for half the year. It is an equatorial sundial and I have attached an image of the dial plates. The two plates can be printed on card stock and sealed in plastic to protect them from the weather. To give the sundial rigidity the right plate can be glued to rigid styrofoam or a piece of wood and the support then cut out to shape. The vertical gnomon is positioned at the centre of the circle. The stiff wire from a clothes hanger works well. The thinner...the better. The left plate is placed so it rotates about the gnomon. To adjust the dial plate to compensate for longitude and the EoT, a copy of the "Correct-A-Dial II" for your longitude would provide the corrections required. The top plate is rotated in the required direction so the sundial will read clock time. The vernier will help you to accurately correct the sundial to the nearest minute. All that is required is a stand that allows the sundial to be adjusted to the desired latitude. Happy Dialling! Carl Sabanski www.mysundial.ca "Get Hooked on Gnomonics!" <> --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Heliochronometer card dials?
Hi All, Rather than making two shepherd's dials - one for the morning, one for the afternoon - you could divide its 360 degree circumference into two 180 degree sections, one for the morning, one for the afternoon. Then there's only one set of hour lines on each side. With a shepherd's dial you have to orientate it so that the shadow is exactly vertical. It occurs to me that one elegant way to ensure this would be to have a slit in the gnomon, like Piers Nicholson's Spot On dials. See www.sundials.co.uk Similarly with a mean time Capuchin dial, you could mark both sides of the dial rather than mixing morning and afternoon on the same side. The simplest mean time dial I know is called a nocturnal ;-) Regards Chris - Original Message - From: fer de vries To: Gerard Hughes ; Sundial List Sent: Tuesday, October 17, 2006 8:27 PM Subject: Re: Heliochronometer card dials? Gerard, You could make a sheperd's dial. These are location specific. Attached is a picture of the scale for such a dial with correction for longitude and equation of time. It would be better if you make two, one for the morning hours and one for the afternoon hours. Red cq blue lines in the picture. Also a Capuchin dial for one latitude can be corrected for longitude and EoT but also split the pattern in two parts. Correction for daylight saving time is no more then adding new numbers to the dial. Such altitude dial will not work accurate around noon but the possibility to make them for clock time is present. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Eindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: Gerard Hughes To: Sundial List Sent: Tuesday, October 17, 2006 8:36 PM Subject: Heliochronometer card dials? Ok, so I do realize that "heliochronometer" and "card dial" are sort of mutually exclusive. I’m looking for a way to make some easy to read card dials that read in standard mean time.I work at a number of historical reenactment fairs and I’d love a quick and portable way to show people how fun sundials can be and that sundials can be accurate. I have a number of universal ring dials but they read LAT. I’d like the dial to read in mean time because initially I’d like to be able to skip the explanation of Local Apparent Time vs. Mean Time and such. I realize that altitudinal card dials are not the most accurate, but since there is no such thing as a pocket Schmoyer dial I’m looking for an alternative that offers simplicity and a hook to catch people’s interest--and I'll be using them in the summer so the sun will have some altitude for the dial to discern. *I’m considering drafting latitude, longitude and date specific Capuchin dials corrected for daylight savings and the equation of time. I realize these dials would be one offs only of use at one location at one date, but since card dials can be drafted fairly easily this seems like a reasonable way to go. Granted, one can make a "universal" Capuchin dial that compensates for latitude and the time of the year, but such a dial still reads in LAT--Perhaps I could make two rotating hour wheels that line up with the hour scale to set for daylight savings, longitude offset from the center of the time zone and the equation of time (one for am and one for pm--I don't think there is a way to make a single wheel work)I’m wondering if people have any alternate suggestions and ways to make drafting more efficient on my Adobe CS2 equipped non-Intel Mac? (that is, I don't have Delta CAD at the moment.)Thanks,Gerard*Others may think that the path of the sun is fascinating as it is and doesn’t need to be equated with mean time, but I, personally, didn’t become fascinated by dialing until I discovered all the reasons why the dials I saw in parks didn’t read clock time and I assume that others may be dismissive of sundials for similar reasons. ---https://lists.uni-koeln.de/mailman/listinfo/sundial ---https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Heliochronometer card dials
Peter Mayer wrote: >A while back Gerard Hughes started a thread on accurate card dials: >I've often thought that if I have the time, I'll write the DeltaCad >code to generate the EoT adjustment for the Merchant dial. But if >someone else has the leisure to do it first, I'll be the first to applaud! 'Leisure' is a good word in this context as it took me best part of a month to calculate all the tiny offsets and then convert them into separatly rotated 'verniers' for each month for my Lindi/SOL heliochronometer which is, as yet, only 80% completed after three years in the making as I keep changing my mind about the sun sighting arrangement. Clever though it is, some aspects of the original P&G SOL Horometer I found somewhat clumsy. ("An ugly dial with an ugly name" as I believe Mr. Gibbs called it). That swivelling blunt 'arrow' pointer for longitudinal offset for example. My LindiSOL incorporates an additional central 'ring' which allows for both daylight saving AND longitudinal offset adjustment. The plate artwork is in Mac Adobe Illustrator format but I can send a PDF and jpeg of the finished plates and base if anyone is interested. Tony Moss Lindisfarne Sundials. P.S. I have heard it suggested that Pilkington only calculated the first and last of the 'vernier' line angles with equal spacing in between. --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Heliochronometer card dials
Hi, A while back Gerard Hughes started a thread on accurate card dials: Ok, so I do realize that "heliochronometer" and "card dial" are sort of mutually exclusive. I’m looking for a way to make some easy to read card dials that read in standard mean time. One dial which is both a heliochronometer and a card dial is that devised by Charles J. Merchant. The dial, an card equitorial dial, appears to be based on the Pilkington Gibbs Sol Horometer. It was described in Scientific American in March, 1964. I'm attaching a jpg which I hope scrapes under the wire for size. (I'll see if I'm able to convert the HTML into a pdf, if anyone desires a copy of the article) I've often thought that if I have the time, I'll write the DeltaCad code to generate the EoT adjustment for the Merchant dial. But if someone else has the leisure to do it first, I'll be the first to applaud! best wishes, Peter Mayer -- Peter Mayer Politics Department The University of Adelaide, AUSTRALIA 5005 Ph: +61 8 8303 5606 Fax : +61 8 8303 3443 e-mail: [EMAIL PROTECTED] CRICOS Provider Number 00123M --- This email message is intended only for the addressee(s) and contains information that may be confidential and/or copyright. If you are not the intended recipient please notify the sender by reply email and immediately delete this email. Use, disclosure or reproduction of this email by anyone other than the intended recipient(s) is strictly prohibited. No representation is made that this email or any attachments are free of viruses. Virus scanning is recommended and is the responsibility of the recipient. <> --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Heliochronometer card dials?
Hi Gerard, I've had the most fun with modified cardstock vertical dials made with longitude and EOT compensation. They are modified by making sights to point at some distant point, like a particular mountan peak. The sights align the dial for north/south and up/down. It needs a second person to read the time though. they are a fixed latitude/longitude for the site and the curved time lines are good for an entire season. It is usually possible to find some distant point to sight on out here in the Pacific Northwest, usually from a countour map. I've not tried using Google Earth to find a sight point yet, but maybe that would work out. The various sight arms and gnomon fold out from the card stock, Both sides are printed. ( I usually glue one side on to add stiffness and make alignment of the two sides easier) One of the cone dials that gives time to sunset would be a great addition to festivals out in flatlander country, but I never go there. :-) Floating altitude dials seem to be fairly popular. Have fun! Edley McKnight Date sent: Tue, 17 Oct 2006 11:36:02 -0700 (PDT) From: "Gerard Hughes" <[EMAIL PROTECTED]> To: "Sundial List" Copies to: Subject:Heliochronometer card dials? Ok, so I do realize that "heliochronometer" and "card dial" are sort of mutually exclusive. I´m looking for a way to make some easy to read card dials that read in standard mean time. I work at a number of historical reenactment fairs and I´d love a quick and portable way to show people how fun sundials can be and that sundials can be accurate. I have a number of universal ring dials but they read LAT. I´d like the dial to read in mean time because initially I´d like to be able to skip the explanation of Local Apparent Time vs. Mean Time and such. I realize that altitudinal card dials are not the most accurate, but since there is no such thing as a pocket Schmoyer dial I´m looking for an alternative that offers simplicity and a hook to catch people´s interest--and I'll be using them in the summer so the sun will have some altitude for the dial to discern. * I´m considering drafting latitude, longitude and date specific Capuchin dials corrected for daylight savings and the equation of time. I realize these dials would be one offs only of use at one location at one date, but since card dials can be drafted fairly easily this seems like a reasonable way to go. Granted, one can make a "universal" Capuchin dial that compensates for latitude and the time of the year, but such a dial still reads in LAT--Perhaps I could make two rotating hour wheels that line up with the hour scale to set for daylight savings, longitude offset from the center of the time zone and the equation of time (one for am and one for pm--I don't think there is a way to make a single wheel work) I´m wondering if people have any alternate suggestions and ways to make drafting more efficient on my Adobe CS2 equipped non-Intel Mac? (that is, I don't have Delta CAD at the moment.) Thanks, Gerard *Others may think that the path of the sun is fascinating as it is and doesn´t need to be equated with mean time, but I, personally, didn´t become fascinated by dialing until I discovered all the reasons why the dials I saw in parks didn´t read clock time and I assume that others may be dismissive of sundials for similar reasons. --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Heliochronometer card dials?
Hello Fred, What a wonderful dial! I watched the video on his website, and the machining sequences are awesome. This dial looks like the ideal Christmas present for any dial enthusiast who travels. But I wonder what the airport security people would say about it? Cheers, John John Pickard [EMAIL PROTECTED] - Original Message - From: "Fred Sawyer" <[EMAIL PROTECTED]> To: "Dave Bell" <[EMAIL PROTECTED]>; "Sundial List" Sent: Wednesday, October 18, 2006 10:35 AM Subject: Re: Heliochronometer card dials? The Icarus dial can be seen at: http://www.heliosuhren.de/E_main_19_00.html --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Heliochronometer card dials?
Hi Gerard, I'd like the dial to read in mean time because initially I'd like to be able to skip the explanation of Local Apparent Time vs. Mean Time and such. It's not qite chronometer accuracy, but feel free to use modify the time scale in this card ring dial. It was done in MS Word. http://leewm.freeshell.org/origami/ringdial.doc Rgds weemeng --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Heliochronometer card dials?
The Icarus dial can be seen at: http://www.heliosuhren.de/E_main_19_00.html - Original Message - From: "Dave Bell" <[EMAIL PROTECTED]> To: "Sundial List" Sent: Tuesday, October 17, 2006 5:35 PM Subject: Re: Heliochronometer card dials? On Tue, 17 Oct 2006, Fred Sawyer wrote: The Icarus dial by Carlo Heller is a universal ring dial with adjusments for longitude, dst, and equation of time. I'm not familiar with that design, and couldn't (quickly) find a reference to it, but what about something like this, cut from heavy cardstock? http://www.aboutstonehenge.info/index.php?pg=sundial-pocket http://www.online-relics.com/acatalog/Ringdials2.html Or is it yet another L.A.T. dial? Dave --- https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial
RE: Heliochronometer card dials?
Helmut Sonderegger's program "Sonne" calculates shepherd or cylindrical dials corrected for longitude and EoT. The program generates the location specific specific drawings as in Fer's attachment. You can download "Sonne" from his website. http://web.utanet.at/sondereh/sun.htm Roger Bailey Walking Shadow Designs N 48.66 W 123.4 -Original Message-From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]On Behalf Of fer de vriesSent: October 17, 2006 12:28 PMTo: Gerard Hughes; Sundial ListSubject: Re: Heliochronometer card dials? Gerard, You could make a sheperd's dial. These are location specific. Attached is a picture of the scale for such a dial with correction for longitude and equation of time. It would be better if you make two, one for the morning hours and one for the afternoon hours. Red cq blue lines in the picture. Also a Capuchin dial for one latitude can be corrected for longitude and EoT but also split the pattern in two parts. Correction for daylight saving time is no more then adding new numbers to the dial. Such altitude dial will not work accurate around noon but the possibility to make them for clock time is present. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Eindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: Gerard Hughes To: Sundial List Sent: Tuesday, October 17, 2006 8:36 PM Subject: Heliochronometer card dials? Ok, so I do realize that "heliochronometer" and "card dial" are sort of mutually exclusive. I’m looking for a way to make some easy to read card dials that read in standard mean time.I work at a number of historical reenactment fairs and I’d love a quick and portable way to show people how fun sundials can be and that sundials can be accurate. I have a number of universal ring dials but they read LAT. I’d like the dial to read in mean time because initially I’d like to be able to skip the explanation of Local Apparent Time vs. Mean Time and such. I realize that altitudinal card dials are not the most accurate, but since there is no such thing as a pocket Schmoyer dial I’m looking for an alternative that offers simplicity and a hook to catch people’s interest--and I'll be using them in the summer so the sun will have some altitude for the dial to discern. *I’m considering drafting latitude, longitude and date specific Capuchin dials corrected for daylight savings and the equation of time. I realize these dials would be one offs only of use at one location at one date, but since card dials can be drafted fairly easily this seems like a reasonable way to go. Granted, one can make a "universal" Capuchin dial that compensates for latitude and the time of the year, but such a dial still reads in LAT--Perhaps I could make two rotating hour wheels that line up with the hour scale to set for daylight savings, longitude offset from the center of the time zone and the equation of time (one for am and one for pm--I don't think there is a way to make a single wheel work)I’m wondering if people have any alternate suggestions and ways to make drafting more efficient on my Adobe CS2 equipped non-Intel Mac? (that is, I don't have Delta CAD at the moment.)Thanks,Gerard*Others may think that the path of the sun is fascinating as it is and doesn’t need to be equated with mean time, but I, personally, didn’t become fascinated by dialing until I discovered all the reasons why the dials I saw in parks didn’t read clock time and I assume that others may be dismissive of sundials for similar reasons. ---https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial
RE: Heliochronometer card dials?
There is a type of Standard Time dial that goes by several names: SCADD, Spider, or Singleton sundials. It has built-in Equation of Time wavy hour lines and date lines. It can have a polar axis or vertical gnomon. You can make it horizontal, inclining or declining. And is simple to use. The only way I know to easily design one is by using a Delta Cad macro by Steve Lelievre. I will send you a sample drawing of one off line since the drawing size is too big for the List email filter. If you get Delta Cad, you can download Steve’s free macro at: http://users.eastlink.ca/~srgl/deltacad.htm John C. From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Gerard Hughes Sent: Tuesday, October 17, 2006 11:36 AM To: Sundial List Subject: Heliochronometer card dials? Ok, so I do realize that "heliochronometer" and "card dial" are sort of mutually exclusive. I’m looking for a way to make some easy to read card dials that read in standard mean time. I work at a number of historical reenactment fairs and I’d love a quick and portable way to show people how fun sundials can be and that sundials can be accurate. I have a number of universal ring dials but they read LAT. I’d like the dial to read in mean time because initially I’d like to be able to skip the explanation of Local Apparent Time vs. Mean Time and such. I realize that altitudinal card dials are not the most accurate, but since there is no such thing as a pocket Schmoyer dial I’m looking for an alternative that offers simplicity and a hook to catch people’s interest--and I'll be using them in the summer so the sun will have some altitude for the dial to discern. * I’m considering drafting latitude, longitude and date specific Capuchin dials corrected for daylight savings and the equation of time. I realize these dials would be one offs only of use at one location at one date, but since card dials can be drafted fairly easily this seems like a reasonable way to go. Granted, one can make a "universal" Capuchin dial that compensates for latitude and the time of the year, but such a dial still reads in LAT--Perhaps I could make two rotating hour wheels that line up with the hour scale to set for daylight savings, longitude offset from the center of the time zone and the equation of time (one for am and one for pm--I don't think there is a way to make a single wheel work) I’m wondering if people have any alternate suggestions and ways to make drafting more efficient on my Adobe CS2 equipped non-Intel Mac? (that is, I don't have Delta CAD at the moment.) Thanks, Gerard *Others may think that the path of the sun is fascinating as it is and doesn’t need to be equated with mean time, but I, personally, didn’t become fascinated by dialing until I discovered all the reasons why the dials I saw in parks didn’t read clock time and I assume that others may be dismissive of sundials for similar reasons. --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Heliochronometer card dials?
On Tue, 17 Oct 2006, Fred Sawyer wrote: > The Icarus dial by Carlo Heller is a universal ring dial with adjusments for > longitude, dst, and equation of time. I'm not familiar with that design, and couldn't (quickly) find a reference to it, but what about something like this, cut from heavy cardstock? http://www.aboutstonehenge.info/index.php?pg=sundial-pocket http://www.online-relics.com/acatalog/Ringdials2.html Or is it yet another L.A.T. dial? Dave --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Heliochronometer card dials?
>Natrually, that would be ideal. I'd love to own one with an adjustable hour scale but to my knowledge, no such Ring Dial has been commercially available in recent history (or, perhaps, ever been mass produced) and making one would require a rather expensive commision or dedicating myself to learning how to etch and machine brass and taking on a fair bit of cost in practicing and tooling up to execute. If anyone knows of such a dial being available I'd be interested.< The Icarus dial by Carlo Heller is a universal ring dial with adjusments for longitude, dst, and equation of time. - Original Message - From: Gerard Hughes To: Sundial List Sent: Tuesday, October 17, 2006 4:58 PM Subject: Re: Heliochronometer card dials? Chris Lusby Taylor wrote on 10/17/06, 1:28 PM: "Actually, I thought "historical reenactment" and "standard mean time" are sort of mutually exclusive."Well, in the strict sense you are right, although there are historical re-enactments that take place in time periods after time was standardized. In my case I can make concessions to reality to get people interested. I'm not, in this instance, trying to be strictly historically accurate but to bridge a gap. Most people aren't, frankly, impressed that you can tell them Local Aparrent Mean time. They just look at their watch and note that you have the "wrong" time of day. I'm occasionally performing at "Renaisance" faires rahter than somethning like Plymoth Plantation. Renaissance fairs tend to be a little loose on the details these days so a certain amount of cheating is within the bounds of the type of event. "Of these, the most portable form is the Universal Equatorial (or Equinoctial) Ring Dial. To read mean time, its equatorial ring must be made to rotate: most do not."Natrually, that would be ideal. I'd love to own one with an adjustable hour scale but to my knowledge, no such Ring Dial has been commercially available in recent history (or, perhaps, ever been mass produced) and making one would require a rather expensive commision or dedicating myself to learning how to etch and machine brass and taking on a fair bit of cost in practicing and tooling up to execute. If anyone knows of such a dial being available I'd be interested. ---https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Heliochronometer card dials?
Chris Lusby Taylor wrote on 10/17/06, 1:28 PM: "Actually, I thought "historical reenactment" and "standard mean time" are sort of mutually exclusive." Well, in the strict sense you are right, although there are historical re-enactments that take place in time periods after time was standardized. In my case I can make concessions to reality to get people interested. I'm not, in this instance, trying to be strictly historically accurate but to bridge a gap. Most people aren't, frankly, impressed that you can tell them Local Aparrent Mean time. They just look at their watch and note that you have the "wrong" time of day. I'm occasionally performing at "Renaisance" faires rahter than somethning like Plymoth Plantation. Renaissance fairs tend to be a little loose on the details these days so a certain amount of cheating is within the bounds of the type of event. "Of these, the most portable form is the Universal Equatorial (or Equinoctial) Ring Dial. To read mean time, its equatorial ring must be made to rotate: most do not." Natrually, that would be ideal. I'd love to own one with an adjustable hour scale but to my knowledge, no such Ring Dial has been commercially available in recent history (or, perhaps, ever been mass produced) and making one would require a rather expensive commision or dedicating myself to learning how to etch and machine brass and taking on a fair bit of cost in practicing and tooling up to execute. If anyone knows of such a dial being available I'd be interested. --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Heliochronometer card dials?
Actually, I thought "historical reenactment" and "standard mean time" are sort of mutually exclusive. Most mean time dials have uniform 15 degree hour spacing, so setting zone time, daylight saving, or whatever, is just a matter of rotating the dial. Of these, the most portable form is the Universal Equatorial (or Equinoctial) Ring Dial. To read mean time, its equatorial ring must be made to rotate: most do not. Not exactly a card dial, but very portable and the best I can think of. Regards Chris - Original Message - From: Gerard Hughes To: Sundial List Sent: Tuesday, October 17, 2006 7:36 PM Subject: Heliochronometer card dials? Ok, so I do realize that "heliochronometer" and "card dial" are sort of mutually exclusive. I’m looking for a way to make some easy to read card dials that read in standard mean time.I work at a number of historical reenactment fairs and I’d love a quick and portable way to show people how fun sundials can be and that sundials can be accurate. I have a number of universal ring dials but they read LAT. I’d like the dial to read in mean time because initially I’d like to be able to skip the explanation of Local Apparent Time vs. Mean Time and such. I realize that altitudinal card dials are not the most accurate, but since there is no such thing as a pocket Schmoyer dial I’m looking for an alternative that offers simplicity and a hook to catch people’s interest--and I'll be using them in the summer so the sun will have some altitude for the dial to discern. *I’m considering drafting latitude, longitude and date specific Capuchin dials corrected for daylight savings and the equation of time. I realize these dials would be one offs only of use at one location at one date, but since card dials can be drafted fairly easily this seems like a reasonable way to go. Granted, one can make a "universal" Capuchin dial that compensates for latitude and the time of the year, but such a dial still reads in LAT--Perhaps I could make two rotating hour wheels that line up with the hour scale to set for daylight savings, longitude offset from the center of the time zone and the equation of time (one for am and one for pm--I don't think there is a way to make a single wheel work)I’m wondering if people have any alternate suggestions and ways to make drafting more efficient on my Adobe CS2 equipped non-Intel Mac? (that is, I don't have Delta CAD at the moment.)Thanks,Gerard*Others may think that the path of the sun is fascinating as it is and doesn’t need to be equated with mean time, but I, personally, didn’t become fascinated by dialing until I discovered all the reasons why the dials I saw in parks didn’t read clock time and I assume that others may be dismissive of sundials for similar reasons. ---https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Heliochronometer card dials?
Gerard, You could make a sheperd's dial. These are location specific. Attached is a picture of the scale for such a dial with correction for longitude and equation of time. It would be better if you make two, one for the morning hours and one for the afternoon hours. Red cq blue lines in the picture. Also a Capuchin dial for one latitude can be corrected for longitude and EoT but also split the pattern in two parts. Correction for daylight saving time is no more then adding new numbers to the dial. Such altitude dial will not work accurate around noon but the possibility to make them for clock time is present. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkringmailto:[EMAIL PROTECTED]http://www.de-zonnewijzerkring.nl Eindhoven, Netherlandslat. 51:30 N long. 5:30 E - Original Message - From: Gerard Hughes To: Sundial List Sent: Tuesday, October 17, 2006 8:36 PM Subject: Heliochronometer card dials? Ok, so I do realize that "heliochronometer" and "card dial" are sort of mutually exclusive. I’m looking for a way to make some easy to read card dials that read in standard mean time.I work at a number of historical reenactment fairs and I’d love a quick and portable way to show people how fun sundials can be and that sundials can be accurate. I have a number of universal ring dials but they read LAT. I’d like the dial to read in mean time because initially I’d like to be able to skip the explanation of Local Apparent Time vs. Mean Time and such. I realize that altitudinal card dials are not the most accurate, but since there is no such thing as a pocket Schmoyer dial I’m looking for an alternative that offers simplicity and a hook to catch people’s interest--and I'll be using them in the summer so the sun will have some altitude for the dial to discern. *I’m considering drafting latitude, longitude and date specific Capuchin dials corrected for daylight savings and the equation of time. I realize these dials would be one offs only of use at one location at one date, but since card dials can be drafted fairly easily this seems like a reasonable way to go. Granted, one can make a "universal" Capuchin dial that compensates for latitude and the time of the year, but such a dial still reads in LAT--Perhaps I could make two rotating hour wheels that line up with the hour scale to set for daylight savings, longitude offset from the center of the time zone and the equation of time (one for am and one for pm--I don't think there is a way to make a single wheel work)I’m wondering if people have any alternate suggestions and ways to make drafting more efficient on my Adobe CS2 equipped non-Intel Mac? (that is, I don't have Delta CAD at the moment.)Thanks,Gerard*Others may think that the path of the sun is fascinating as it is and doesn’t need to be equated with mean time, but I, personally, didn’t become fascinated by dialing until I discovered all the reasons why the dials I saw in parks didn’t read clock time and I assume that others may be dismissive of sundials for similar reasons. ---https://lists.uni-koeln.de/mailman/listinfo/sundial Image1.gif Description: GIF image --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Heliochronometer card dials?
Ok, so I do realize that "heliochronometer" and "card dial" are sort of mutually exclusive. I’m looking for a way to make some easy to read card dials that read in standard mean time. I work at a number of historical reenactment fairs and I’d love a quick and portable way to show people how fun sundials can be and that sundials can be accurate. I have a number of universal ring dials but they read LAT. I’d like the dial to read in mean time because initially I’d like to be able to skip the explanation of Local Apparent Time vs. Mean Time and such. I realize that altitudinal card dials are not the most accurate, but since there is no such thing as a pocket Schmoyer dial I’m looking for an alternative that offers simplicity and a hook to catch people’s interest--and I'll be using them in the summer so the sun will have some altitude for the dial to discern. * I’m considering drafting latitude, longitude and date specific Capuchin dials corrected for daylight savings and the equation of time. I realize these dials would be one offs only of use at one location at one date, but since card dials can be drafted fairly easily this seems like a reasonable way to go. Granted, one can make a "universal" Capuchin dial that compensates for latitude and the time of the year, but such a dial still reads in LAT--Perhaps I could make two rotating hour wheels that line up with the hour scale to set for daylight savings, longitude offset from the center of the time zone and the equation of time (one for am and one for pm--I don't think there is a way to make a single wheel work) I’m wondering if people have any alternate suggestions and ways to make drafting more efficient on my Adobe CS2 equipped non-Intel Mac? (that is, I don't have Delta CAD at the moment.) Thanks, Gerard *Others may think that the path of the sun is fascinating as it is and doesn’t need to be equated with mean time, but I, personally, didn’t become fascinated by dialing until I discovered all the reasons why the dials I saw in parks didn’t read clock time and I assume that others may be dismissive of sundials for similar reasons. --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Homan Heliochronometer
The right url ishttp://www.precisionsundials.com/sundial_list.htmwithout point and 'clickable' Willy LeendersHasselt, Flanders (Belgium) Op 15-nov-05, om 18:54 heeft [EMAIL PROTECTED] het volgende geschreven:Tony Moss of Lindisfarne Sundials sent me some photos of different models of Homan's sundials. I have placed them for viewing at www.precisionsundials.com/sundial_list.htm. -Bill
Homan Heliochronometer
Tony Moss of Lindisfarne Sundials sent me some photos of different models of Homan's sundials. I have placed them for viewing at www.precisionsundials.com/sundial_list.htm. -Bill
Re: Southern hemisphere heliochronometer?
I think I did see photos of one from South Africa in an e-mail about 2 years ago from someone who wanted to know more about a sundial they had. It looked alot like a cross between a Pilkington and Gibbs Sol Horometer and their better known Heliochronometer as I recall. I could kick myself in that I seem to have deleted the photos they sent me. -Bill In a message dated 11/15/2005 4:15:02 AM Eastern Standard Time, [EMAIL PROTECTED] writes: Althugh William Homan worked professionally in South Africa (and filed patents from there) all the instruments by him that I've ever seen have a Glasgow address. Bill, have you come across one made in South Africa?
RE: Southern hemisphere heliochronometer?
Bill Gottesman wrote "The answer is yes. I think it was called Homan's Heliochronometer, and was made in South Africa. ..." Althugh William Homan worked professionally in South Africa (and filed patents from there) all the instruments by him that I've ever seen have a Glasgow address. Bill, have you come across one made in South Africa? I have seen one by him made (at 22 Renfrew Street Glasgow) for about 8 degrees North - probably Trincomalee. Not quite the Southern hemisphere, but pretty close! Andrew James 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 -
Re: Southern hemisphere heliochronometer?
Dave, Pilkington and Gibbs certainly made a model of their heliochronometer for the southern hemisphere. I have a photo of one if you would like to see it. It's a Type 5, Serial number 598. Mike Shaw 53.37 North03.02 West www.wiz.to/sundials
Re: Southern hemisphere heliochronometer?
Yes, there was a batch of them made for one of the African expeditions in the last war, I believe, but that fizzled out and they were not used. Folkard and Ward of "Sundials Australia" have one. They were numbered. I am on the road so I dont have access to my resources, otherwise I would add more details. Simon --- [EMAIL PROTECTED] wrote: > The answer is yes. I think it was called Homan's > Heliochronometer, and was > made in South Aftrica. Google was not that helpful. > > -Bill Gottesman > > In a message dated 11/14/2005 9:00:23 PM Eastern > Standard Time, > [EMAIL PROTECTED] writes: > > Hi all: > > > > I have a question for list members. Does anyone > know if a Southern > > hemisphere heliochronometer has ever been > produced? I would think one must > > have been, but can find no reference to any on the > net. > > Perhaps the Pilkington could be made to operate > below the equator? > -
Re: Southern hemisphere heliochronometer?
The answer is yes. I think it was called Homan's Heliochronometer, and was made in South Aftrica. Google was not that helpful. -Bill Gottesman In a message dated 11/14/2005 9:00:23 PM Eastern Standard Time, [EMAIL PROTECTED] writes: Hi all: I have a question for list members. Does anyone know if a Southern hemisphere heliochronometer has ever been produced? I would think one must have been, but can find no reference to any on the net. Perhaps the Pilkington could be made to operate below the equator?
Southern hemisphere heliochronometer?
Hi all: I have a question for list members. Does anyone know if a Southern hemisphere heliochronometer has ever been produced? I would think one must have been, but can find no reference to any on the net. Perhaps the Pilkington could be made to operate below the equator? TIA Dave G. http://atensundials.com -
Re: Heliochronometer by Homan
Hi Andrew: One thing you can do is read the patent images and look for citations of prior art. Sometimes this is on the first written page, sometimes on the last page and sometimes in the description of prior art. Once you have the patent number then go there and look for more citations. I have some Sundial Patents at: <http://www.pacificsites.com/~brooke/SD_Pat2.htm> Have Fun, Brooke Andrew James wrote: > Brooke > > Thank you for that - and thanks Fred for sending me the file off-list. > > >From that I now see that the US Patent 946,223 is actually for a design > completely different from UK 18,568 of 1911 and the instrument I saw! > > As I understand that he made at least two other known mean time dials on yet > another principle, Homan would seem to have been quite a prolific inventor > in the field. > > Perhaps he took out other US Patents? But as you say apparently one can't > search for the inventor on-line at that date. I'll have a look, in case, for > other UK ones using good old paper-based technology! > > Andrew James > N 51 04' W 01 18' > > -Original Message- > From: Brooke Clarke [mailto:[EMAIL PROTECTED] > Sent: 31 July 2002 17:03 > To: sundial@rrz.uni-koeln.de > Subject: Re: Heliochronometer by Homan > > All US patents are on line. > Sources for free on line TIF viewers can be found under help\How to Access > Patent Full-page Images. > Older patents can only be accessed by traditional US class number or patent > number, none of the other search methods will work. > - -
RE: Heliochronometer by Homan
Brooke Thank you for that - and thanks Fred for sending me the file off-list. >From that I now see that the US Patent 946,223 is actually for a design completely different from UK 18,568 of 1911 and the instrument I saw! As I understand that he made at least two other known mean time dials on yet another principle, Homan would seem to have been quite a prolific inventor in the field. Perhaps he took out other US Patents? But as you say apparently one can't search for the inventor on-line at that date. I'll have a look, in case, for other UK ones using good old paper-based technology! Andrew James N 51 04' W 01 18' -Original Message- From: Brooke Clarke [mailto:[EMAIL PROTECTED] Sent: 31 July 2002 17:03 To: sundial@rrz.uni-koeln.de Subject: Re: Heliochronometer by Homan All US patents are on line. Sources for free on line TIF viewers can be found under help\How to Access Patent Full-page Images. Older patents can only be accessed by traditional US class number or patent number, none of the other search methods will work. -
Re: Heliochronometer by Homan
Hi: All US patents are on line. Sources for free on line TIF viewers can be found under help\How to Access Patent Full-page Images. Older patents can only be accessed by traditinal US class number or patent number, none of the other search methods will work. US 946,223 can be seen at: <http://164.195.100.11/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1='946,223'.WKU.&OS=PN/946,223&RS=PN/946,223> Have Fun, Brooke Clarke PS the "<... >" should keep the link from breaking fwsawyer wrote: > The Homan sundial was also patented in the U.S.: Patent # 946,223 issued on > 11 Jan. 1910. I have a copy of the patent papers in a 320Kb pdf file which > I will send to anyone who requests it (off-list please). > > Fred Sawyer > > - Original Message - > From: "Andrew James" <[EMAIL PROTECTED]> > To: > Sent: Wednesday, July 31, 2002 7:33 AM > Subject: Heliochronometer by Homan > > > I have recently been shown an interesting brass heliochronometer made by > W. > > Homan of Glasgow according to his patent 18,568 of 1911. (I hope to > receive > > a copy of the patent shortly.) > > > > It is quite large, based on a 13 1/2" diameter hemisphere. It has two > > "gnomons", upright brackets carried on and perpendicular to a circular > plate > > 11" diameter. The plate has, over an adjustable 15 degree arc at its edge, > a > > scale divided in minutes, and can be rotated by hand against an outer > fixed > > ring marked with hours from 1 to 12 twice. Each upright carries a half > > analemma, one for positive and the other for negative solar declination > > (summer and winter), and a slit - with in one case a small hole adding a > > nodus to the slit - to project light onto the half analemma on the other > > upright 7 7/8" (200 mm) away. > > > > It is set for a latitude (not adjustable) of about 7 degrees North, and a > > time difference from the local meridian of 5 minutes (added to the > reading, > > so it was sited just over 1 degree West). This indicates it was made for > use > > not in Britain but somewhere tropical, perhaps West Africa or Ceylon. > > > > Has anyone come across other example(s), or information about this device > or > > its maker? > > > > Andrew James > > N 51 04' W 01 18' > > - > > > > - -
Re: Heliochronometer by Homan
The Homan sundial was also patented in the U.S.: Patent # 946,223 issued on 11 Jan. 1910. I have a copy of the patent papers in a 320Kb pdf file which I will send to anyone who requests it (off-list please). Fred Sawyer - Original Message - From: "Andrew James" <[EMAIL PROTECTED]> To: Sent: Wednesday, July 31, 2002 7:33 AM Subject: Heliochronometer by Homan > I have recently been shown an interesting brass heliochronometer made by W. > Homan of Glasgow according to his patent 18,568 of 1911. (I hope to receive > a copy of the patent shortly.) > > It is quite large, based on a 13 1/2" diameter hemisphere. It has two > "gnomons", upright brackets carried on and perpendicular to a circular plate > 11" diameter. The plate has, over an adjustable 15 degree arc at its edge, a > scale divided in minutes, and can be rotated by hand against an outer fixed > ring marked with hours from 1 to 12 twice. Each upright carries a half > analemma, one for positive and the other for negative solar declination > (summer and winter), and a slit - with in one case a small hole adding a > nodus to the slit - to project light onto the half analemma on the other > upright 7 7/8" (200 mm) away. > > It is set for a latitude (not adjustable) of about 7 degrees North, and a > time difference from the local meridian of 5 minutes (added to the reading, > so it was sited just over 1 degree West). This indicates it was made for use > not in Britain but somewhere tropical, perhaps West Africa or Ceylon. > > Has anyone come across other example(s), or information about this device or > its maker? > > Andrew James > N 51 04' W 01 18' > - > -
Re: Heliochronometer by Homan
Dear Andrew, have a look at the most recent 'Sundial Page' in Clocks magazine (written by Chris Daniel of the BSS), which deals with these instruments made by Homan. He too has just found an exaple, and would like to know of other examples. regards peter tandy At 12:33 PM 7/31/02 +0100, you wrote: >I have recently been shown an interesting brass heliochronometer made by W. >Homan of Glasgow according to his patent 18,568 of 1911. (I hope to receive >a copy of the patent shortly.) > >It is quite large, based on a 13 1/2" diameter hemisphere. It has two >"gnomons", upright brackets carried on and perpendicular to a circular plate >11" diameter. The plate has, over an adjustable 15 degree arc at its edge, a >scale divided in minutes, and can be rotated by hand against an outer fixed >ring marked with hours from 1 to 12 twice. Each upright carries a half >analemma, one for positive and the other for negative solar declination >(summer and winter), and a slit - with in one case a small hole adding a >nodus to the slit - to project light onto the half analemma on the other >upright 7 7/8" (200 mm) away. > >It is set for a latitude (not adjustable) of about 7 degrees North, and a >time difference from the local meridian of 5 minutes (added to the reading, >so it was sited just over 1 degree West). This indicates it was made for use >not in Britain but somewhere tropical, perhaps West Africa or Ceylon. > >Has anyone come across other example(s), or information about this device or >its maker? > >Andrew James >N 51 04' W 01 18' >- > > -
Heliochronometer by Homan
I have recently been shown an interesting brass heliochronometer made by W. Homan of Glasgow according to his patent 18,568 of 1911. (I hope to receive a copy of the patent shortly.) It is quite large, based on a 13 1/2" diameter hemisphere. It has two "gnomons", upright brackets carried on and perpendicular to a circular plate 11" diameter. The plate has, over an adjustable 15 degree arc at its edge, a scale divided in minutes, and can be rotated by hand against an outer fixed ring marked with hours from 1 to 12 twice. Each upright carries a half analemma, one for positive and the other for negative solar declination (summer and winter), and a slit - with in one case a small hole adding a nodus to the slit - to project light onto the half analemma on the other upright 7 7/8" (200 mm) away. It is set for a latitude (not adjustable) of about 7 degrees North, and a time difference from the local meridian of 5 minutes (added to the reading, so it was sited just over 1 degree West). This indicates it was made for use not in Britain but somewhere tropical, perhaps West Africa or Ceylon. Has anyone come across other example(s), or information about this device or its maker? Andrew James N 51 04' W 01 18' -
Re: The "heliochronometer"
John et al, My apologies. I was looking under "H". The definition says "precision". Should this aspect be more "precise"? i.e. what degree of precision should we expect? Bob [EMAIL PROTECTED] wrote: > > Hi Bob et al, > > "heliochronometer" is indeed listed in the BSS Glossary, under the "Dial > types" category. The definition given is: > > "a precision sundial which incorporates some means to allow it to read civil > (or mean) time. This is usually achieved by incorporating an EoT cam (as in > the Pilkington and Gibbs heliochronometer) or by projecting an spot of light > onto an analemma. Note: some authors use the term to describe any precision > sundial" > > No doubt this definition could be improved on: I shall watch the views of the > List members with interest. > > Regards, > > John Davis > --- > > > from:Robert Terwilliger <[EMAIL PROTECTED]> > > date:Fri, 21 Jun 2002 12:26:18 > > to: sundial@rrz.uni-koeln.de > > subject: Re: The "heliochronometer" > > > > Fellow dialists, > > > > What does the group think the criteria for a "heliochronometer" should > > be? > > > > Is there a definition? John Davis' most excellent glossary does not > > include the term. > > > > Regards, > > > > Bob Terwilliger > > > > - > > Dr J R Davis > Flowton Dials > N52d 08m: E1d 05m > - -
Re: The "heliochronometer"
Hi Bob et al, "heliochronometer" is indeed listed in the BSS Glossary, under the "Dial types" category. The definition given is: "a precision sundial which incorporates some means to allow it to read civil (or mean) time. This is usually achieved by incorporating an EoT cam (as in the Pilkington and Gibbs heliochronometer) or by projecting an spot of light onto an analemma. Note: some authors use the term to describe any precision sundial" No doubt this definition could be improved on: I shall watch the views of the List members with interest. Regards, John Davis --- > from:Robert Terwilliger <[EMAIL PROTECTED]> > date:Fri, 21 Jun 2002 12:26:18 > to: sundial@rrz.uni-koeln.de > subject: Re: The "heliochronometer" > > Fellow dialists, > > What does the group think the criteria for a "heliochronometer" should > be? > > Is there a definition? John Davis' most excellent glossary does not > include the term. > > Regards, > > Bob Terwilliger > > - Dr J R Davis Flowton Dials N52d 08m: E1d 05m -
The "heliochronometer"
Fellow dialists, What does the group think the criteria for a "heliochronometer" should be? Is there a definition? John Davis' most excellent glossary does not include the term. Regards, Bob Terwilliger -
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 - -
RE: heliochronometer
Thanks Fritz. I will use this information and look up the copy at the public library. I have found the libraries in local major cities pretty good for archiving old magazines. Roger Bailey N 51 W 115 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Fritz Stumpges Sent: March 6, 2002 2:05 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 - -
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 -
heliochronometer
There is an article in Sky & Telescope magazine December 1994 that inspired the heliochronometers I made. Peter -- Peter Hirtle [EMAIL PROTECTED] Seattle, WA. -
Flandrau Heliochronometer Photos on Registry
Hello all, With Robert Terwilliger's and Robert Kellog's patient help, I've updated all known sundials in Arizona on the NASS registry. Included are several fine photos and a lengthly description of my Flandrau Planetarium Heliochronometer. Go to: http://www.sundials.org/registry/ and click on "Arizona". Scroll down to Tucson and look for sundial # 464. John John L. Carmichael Jr.Sundial Sculptures925 E. Foothills Dr.Tucson Arizona 85718USA Tel: 520-696-1709Email: [EMAIL PROTECTED]Website: <http://www.sundialsculptures.com>
My New Flandrau Heliochronometer
Hello all: After two years of stop-start design and construction, I'm very proud to announce that I have just installed my best sundial to date at the Flandrau Planetarium and Science Center, located on the campus of The University of Arizona. This is a huge 63" x 41" stone monofilar heliochronometer with many many different functions. After much testing, we are consistantly achieving 10 seconds time reading precision!!! Hope you like it, I can't wait to hear your comments! Flandrau Planetearium has posted it on their website at: http://w3.arizona.edu/~flandrau/exhibits/heliochronometer.htm Robert Terwilliger will soon have additional fotos and info about it on the NASS Sundial Registry. Best John John L. Carmichael Jr.Sundial Sculptures925 E. Foothills Dr.Tucson Arizona 85718USA Tel: 520-696-1709Email: [EMAIL PROTECTED]Website: <http://www.sundialsculptures.com>
Carmichael heliochronometer
Hello all: I thought you'd be interested in seeing some sample fotos at of my equatorial heliochronometer featuring the bead-in-hole shadow sharpener that we've been discussing. Several images of this unique sundial can be seen on Dave Bell's website at: <http://dialist.webjump.com> Link to "Equatorial Heliochronometer by John Carmichael". (I just had to send you some fotos scanned on with my brand new Hewlett Packard ScanJet 5300C, which I love! Thanks for recommending it) I designed and built this dial from scratch, by hand, and without computer assistance in 1995. I used red magogony and teak wood with brass trimmings. It has an interactive rotating alidade with analemma showing declination, EOT and dates every five days and the shadow sharpener nodus. The sundial is made for Tucson Arizona and shows Mountain Standard Time + or- 30 sec. The dial face is two feet across. It is based on a similar heliochronometer described in Mayall pages 193 to 200. I wanted it to look very "renaissance" so I included a lot of extras and a great deal of decoration. It features a solar azimuth scale, a magnetic compass (with cover), a plumb bob with cross wires and complete instrucions on the back. There are also declination and EOT tables. The time and solar azimuth are read by first turning the alidade until the shadow falls on the proper date. There are two tight thin wires (which don't show up well in the fotos) directly over the time and azimuth scales. One wire is directly above the other on the nodus side of the alidade and are parallel to the dial face. Two wires are needed to avoid paralax reading errors. When the two wires are lined up visually, the time and azimuth can be read on the dial face directly below. The face background color is painted emamel with lots of 24K gold leaf! I drew the hour lines with a ultra fine point "Sharpee" pen. I used clear sticky back for the numerals and lettering. The face has 26 coats of very thin polyurethane with 1500 grit wetsandings between coats. Needless-to-say, it took an entire summer to build and it's been very sad to see it degrade and self-destruct over the years. People say it should be in a museum instead of outside. In fact, watching it ungracefully age convinced me to switch to stone sundials and to never again waste my time with wood. At least it will survive in photos. I'd love to see someone else build a similar one in metal (hint Tony and Bill). I've only seen similar dials as pocket versions. I hope to soon post more detailed photos my device at better resolution on Dave Bell's Website. Will let you know. best, John Carmichael Tucson Arizona http://www.azstarnet.com
Re: Pilkington & Gibbs Heliochronometer
Dear Anthony Eden, Thank you so much for your posting about the Pilkington and Gibbs Heliochronometers. Of particular interest to me are all the details you've included. I hope you will keep us advised as this project goes forward. Meanwhile, do you have any photos and/or drawings you can scan and share as email attachments? Also, I hope your posting will encourage others to write of their projects. Details, we crave details. Best wishes, Mac Oglesby Anthony Eden wrote: Yes, I am making a replica of the P & G Heliochronometer. In fact I have been making it for about four years or more ! The trouble is that I have done all the easy bits, have been in and out of hospital a few times since I began and am rather stuck on the more difficult bits. Though difficult to me, it would all no doubt be simple to an experienced metal worker and engineer. I was, and remain, neither. (big snip)
Pilkington & Gibbs Heliochronometer
Pilkington and Gibbs Heliochronometers. Yes, I am making a replica of the P & G Heliochronometer. In fact I have been making it for about four years or more ! The trouble is that I have done all the easy bits, have been in and out of hospital a few times since I began and am rather stuck on the more difficult bits. Though difficult to me, it would all no doubt be simple to an experienced metal worker and engineer. I was, and remain, neither. The Curator of Instruments at the Science Museum in London very kindly arranged for his technicians to dis-assemble their exhibition instrument, and allowed me to photograph and measure all the bits of it. I had never done such a thing before, and was not very good at it. It lead to a number of repeat visits to the Museum each time my attempts to make computer drawings of the various components showed up contradictions in my measurements. I also had to learn how to use a CAD program on a computer, which was time consuming. The most difficult part was the design of the cam that is the key to the operation of the instrument, and which automatically corrects for the EOT. I did not know what a cam was, let alone how to calculate its shape, but knowledgeable friends educated me, and the man who calculates the ephemera for the Nautical Almanac at the Royal Greenwich Observatory, Dr. Yallop, guided me as to the data needed to work out its profile. I would be happy to make my calculations available to anyone who wants them, but I worked them out on a spreadsheet peculiar to the Acorn Archimedes computer I was using at that time, and am ignorant - and doubtful - as to whether I can copy the data / spreadsheets from the RISC system to a format readable on the universal PC. for others to read. Only my completion of the instrument will tell if I got the calculations right, but I got the cam milled-out at the local Technical College on their CNC machine. It looks right. The college also allowed me to help them cast the bits that were best cast, and taught me how to us their big lathes for machining the bits that were too big for the lathe I was in the process of acquiring to do the rest. It has all been great fun, and I have made a lot of sundial friends, not least the instrument makers at the science museum and Theo. van den Heiligenberg , in Holland, with whom I have corresponded ever since he decided to write a monograph on the Instrument (since published on the BSS Bulletin). These instruments are not all that rare. They come up at auction fairly regularly, so Sotherbys told me. The original patent (No. 15,194 of AD 1911) describes the instrument and its working in detail, and has diagrams attached to it. I got my copy from the Patent Office when it was in South Wales, and there was no problem there; the price was £2.86, inclusive of postage. I understand that it is now much more difficult to get copies of patents since the Patent Office was moved to London, and I expect that copies are more expensive. I have also seen the Pilkington & Gibbs sales brochure, probably dated just before or after the Great War, which priced the dials, in various sizes and various materials (gun metal, copper and "rustless iron") at prices ranging from eight to twelve guineas. A glass dome to protect the instrument was an "extra" at two guineas. (A guinea was one pound and one shilling, or £1.05, in modern decimal currency). Their brochure also listed all the most famous purchasers of the dial, starting with the King ! I suspect that they were produced up to 1939, but not after the war. There is one in the grounds of Greenwich Hospital, in need of much TLC, and |I know of one or two others in private hands. The firm also produced a rather similar but ugly heliochronometer called a "Sol-Horometer" It was designed by Pilkington (the Heliochronometer was designed by Gibbs, who was a professional engineer. Pilkington was the financial backer) and it lead to ill feeling between the two partners, as Gibbs thought that Pilkington had cribbed his work. The Pilkington & Gibbs Heliochronometer should be accurate to a minute or so, when properly set up and adjusted. I hope this note will be of interest to some, and apologise for the length of it. Anthony Eden
Re: Heliochronometer
Tom Mchugh wrote: > > My guess is the the most accurate sort of heliochronometer > would have optical means of focusing a solar image on an > analemma (figure 8), and would have optical means of observing > the sun's image to judge when it is centered on the line. > > Time could be conveniently shown on a dial readout, much like an > analog clock dial, geared to the polar axis of the equinoctial dial. Hello, This is my understanding of what is meant by a heliochronometer or SunClock. I have not seen a conventional horizontal sundial described as a heliocronometer in the literature I've read. Russell Porter wrote several articles about various SunClock designs in SciAm years ago. I recently had the good fortune to obtain an original Porter SunClock, one of only two known to exist. The URL below leads to a description about the piece and its operation. http://www.gcstudio.com/sunclock.html Regards, Luke Coletti