Re: analemmatic sundial
What happened to your "Sundials for Learning" business (a few years back) - when you were offering plans for Analemmatic Sundials to schools ? It seems to me, that you already had the appropriate software. Keith Christian. On 2023-05-01 06:44, Donald Christensen wrote: I'm looking for a program to calculate an analemmatic sundial. Can anybody help? Cheers Donald Christensen 0467 332 227 If you focus on what you lack, you'll lose what you have. If you focus on what you have, you gain what you lack. --- https://lists.uni-koeln.de/mailman/listinfo/sundial--- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Map required
In message e1xj1zw-0004rj...@mta1.cl.cam.ac.uk Frank King frank.k...@cl.cam.ac.uk wrote: Dear Tony, What a fun thread you have spawned! Mercator is possibly the most famous Belgian, not that Belgium existed in his day but let's overlook that detail. The mathematics of Mercator's projection is quite challenging. Certainly Mercator himself didn't understand it! The first proper analysis was by Edward Wright who was a Fellow of Gonville and Caius College Cambridge in the days when there were 67 sundials in Caius Court. They are now down to their last six. To be sure the projection distorts sizes so Greenland appears about the same size as Africa but the UK is pretty small and the distortion is minimal. I do not understand Linda's map! As John Foad didn't quite say, this is decidedly an Alex Salmond projection. I'd use Mercator's projection for your project if possible. After all, that's what the Ordnance Survey use, albeit they turn the projection through a right-angle (the equator runs north to south). Peters's projection is really (in my view) the Gall Orthographic (Peters was over 100 years after Gall). It has no special advantages for a region the size of the U.K. I hope you find a proper map soon! Frank --- https://lists.uni-koeln.de/mailman/listinfo/sundial As Frank King mentioned, the subject of map 'projections' can be a tricky one - and most of us probably think of school atlas maps, where it is likely to be one based on conical with two standard parallels, where (as Tony Moss said), Latitude lines will be slightly curved, and Longitude converging to the North. However, Tony definitely wants 'orthogonal' (i.e. straight and at right-angles) lines of Latitude and Longitude - which rather restricts the projections you can use, though Tony did not give his reasons WHY the map had to have these specific properties. Strictly speaking, the UK Ordnance Survey 'National Grid' is not based on a Transverse Mercator projection (as Frank King suggested) - but here are two websites, with more information. http://en.wikipedia.org/wiki/Map_projection http://en.wikipedia.org/wiki/Ordnance_Survey_National_Grid I hope they might be useful, and not even more confusing! Sincerely, Keith Christian. -- --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: An analematic sundial between Capriconio Tropic and Ecuador line
In message CAMjAGnxUBDuCru+tHxTqR_vsvHEiUXaObfSV8SD=myiobbq...@mail.gmail.com Chiu ªô,Chi lian clc...@mx.nthu.edu.tw wrote: Hello Axel: I'd say that the Human Horizontal Dial belongs to the catagory suitable for high latitude. It's not an ideal solution for tropic region because the hour-line's angle difference between 11 to 12 is less than 6° and that between 10 to 12 is less than 13°. Except the winter time, if a 5-foot high child uses his own shadow to try to read the solar time, the accuracy between 10 to 14 would be very poor. Regards, ChiLian For 'low' latitudes, in a school situation, have you considered a Polar Arch sundial - basically like a 'door-frame', where the top of the 'frame' is set at the latitude angle, and its shadow tells time on a scale which is marked on the ground in an East/West line. In very low latitudes (near to the Equator), Polar Arch sundials are normally included as part of outdoor 'climbing-frames' (or any similar interactive playground features) for schools. However, I do not have a link to any photographs - but maybe other members of this list could provide further information, on that type of dial. Regards, Keith Christian. --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Do sundials (in public places), attract 'undesirable' people ?
Our Friends of Port Sunlight group have proposed installing a 'Human Sundial' into a local area, as an attractive interactive feature - and we had obtained the layout plans, from Modern Sunclocks in Scotland. For any UK members of this group, you may know that Port Sunlight (in 'the Wirral' part of Cheshire) is a highly prestigious area, and which is also protected by all kinds of 'heritage' regulations. Our chosen location is known as The Diamond, plus we intend to use local stone. During one of our recent meetings, it was pointed out that the Modern Sunclocks website says that installing this feature into a public area may attract 'undesirable' people (drug addicts, prostitutes, etc) - who would tend to use this Human Sundial as their regular 'meeting-place'. This is detailed at the top of page: www.sunclocks.com/pics/fs-015.htm There is also a link to further 'risks and dangers', of installing one. Although we would really love to have a Sunclock, if this is going to become a meeting place for drug-dealers and alcoholics - then it would certainly not be in keeping with the 'prestigious' nature of this site. My reason for sending this message to the Sundial Mailing List, is to ask if anyone has experience of sundials (in public places) becoming an attraction to 'undesirable' people - such as those I mentioned, above. Basically, we need to decide whether we should proceed with installing this Sunclock in that location - as we do not want to have a feature which might considerably 'lower the tone', of our Port Sunlight area ! Looking forward to any comments and/or advice, concerning this matter. Keith Christian. -- --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Starting a 'Sundial business' - revisited, two years on
Some of you may remember that (about two years ago), I asked for advice on this Mailing List - concerning starting a Sundial-related business. I had recently retired from Teaching, and wanted to combine my interest in Sundials with the possibility of some additional retirement income. At that time, I eventually decided on Sunclocks (Human Sundials) - by starting with a 'Free Franchise' offered by Douglas Hunt, in Scotland. My intention was just to paint these layouts on to School playgrounds. Just in case anyone else is considering doing something similar, I have just found-out that this is now featured in the electronic publication Best Home Business Opportunities Directory, 2008 - which features 24 of the top-rated home-based money-making ideas, in the United Kingdom. It is a totally independent publication, and taking no income from any advertising - plus all its information is well-researched and analysed. This can be bought from www.BusinessOpportunityWatch.com/directory.htm It comes as a PDF file (several dozen pages), costing about 15 Pounds. The entry for Modern Sunclocks, is detailed on page numbers 25 to 27. I am very glad that I began this unusual 'opportunity', plus there are several ways to create a good income from these Human Sundial layouts. You can always rely on Douglas Hunt to give you useful advice, plus he could also help to get your website up to a 'top ranking' on Google. He has even managed to get his own Name to positions one and two, on that 'Search Engine' - and he does not charge a penny for his advice, though (as far as I know) he only gives such assistance by Telephone. You can always contact Douglas via his website at: www.sunclocks.com If anyone else is thinking about starting a Sundial business (of any kind), then all I can say is Go for it - and remember that Schools are the largest 'customer-base' for Sundials (more so than gardens), simply due to the fact that there are many teaching elements in them. (For example - Mathematics, Science, Geography, and even Art/Design). Best Regards, Keith Christian. -- --- https://lists.uni-koeln.de/mailman/listinfo/sundial
RE: sundial in the Company's Garden in Cape Town
Hello, Willy As Roderick Wall suggested, it COULD simply be that this is just intended to 'hide' any mistakes by the original maker. However, another possibility is that those numerals for the hours 5, 6, 7 and 8 were deliberately made that way - so as to make it obvious that these are the morning (a.m.) hours. Perhaps each overlaid 'upside-down V' is to be viewed as an upward-arrow - and maybe representing the sunRISE hours ? Keith Christian. -- --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Seeking advice, on starting a 'sundial business'
I joined this mailing-list a couple of months ago - after taking early retirement (from Teaching), and hope to start a sundial- related business of some kind, which can supplement my 'pension'. After much consideration, I think that I have finally decided on Human Sundials (mainly because I know how popular these are in the educational sector) - but also since they are easy to create, 'interactive', self-advertising and relatively 'vandal-proof'. I was surprised to see just how many (well over a million) entries for 'Human Sundials' are shown by a Google search - which is obviously encouraging, but I thought that I would ask here on this group just to see if anyone can give me some comments or advice. It is my intention (at least to begin with), to simply paint these on to School playgrounds - although I also have a friend who could make colourful 'mosaic' layouts as well, if there is any demand. I already have orders from 4 local Schools, who are wanting this feature painted for them - but can anyone give me suggestions as to other customers I could approach, to have a 'Human Sundial' ? Douglas Hunt at Modern Sunclocks ( www.sunclocks.com ) has given me some guidance and encouragement, by telephone - and he seems to have run a successful 'Human Sundial' business for about 20 years. However, I would prefer to have some 'independent' views from more people in the general sundial arena - hence this message, here. So are there any points that I should be aware of (or indeed even to 'beware' of), in relation to starting a business like this ? With my grateful thanks in advance, for any and all your comments. Sincerely, Keith Christian. -- --- https://lists.uni-koeln.de/mailman/listinfo/sundial
