Dear Chris,Sorry for the delay in responding, but I've been away from home and references. I thought you might be interested in the Oliver dial which, in effect is the 'inverse' of yours. According to Frank Cousins in hi _Sundials_ (London: John Baker, 1969). p188, it was patened by Maj. Gen. Oliver in 1892. (apologies for the grainy quality of the pdf but it will barely squeak under the size limit as it is).
best wishes, Peter Mayer On 11/11/2010 06:58, Chris Dobbie wrote:
Just in the last week I’ve become fascinated with sundials and decided to join this mailing list. This is my first post here and with that said I’d like to say hello to all members and ask that you forgive my noobish questions. I saw a “digital” equatorial sundial for the first time the other day and fell in love with its simple design, just a band of metal bolted to a rock. I soon realized that its simplicity came with a cost to functionality. I’ve since come up with a far less simple design that I think solves most functionality problems including equation of time and the inability of use between 6 pm and 6 am. You can’t really tell from the model but I envision the equatorial ring being able to rotate 360 degrees with markers along its track for longitude and DST correction as well as current times for other cities around the world. One could also make it universal by marking it in degrees and making the base adjustable. If build large scale, minute lines could be added to the analemma. I’ve only recently started researching sundials and the math of the analemma is still confusing me so I have a couple questions.I imagine if I calculated out the amalemma and checked the time at noon this dial would be fairly accurate but how accurate would it be at dawn and dusk? Would the angels of the analemme change?Also, would rotating the equatorial ring affect accuracy? If the dial does work and the amalemma and dial were marked in smaller increments, how accurate do you think it would be? Lastly, I’m wondering if you have ever seen this style of dial before in design or finished form? I have yet to come across one and would love to see any pictures or info that’s out there. Thank you so very much for any and all you can share with me. Cheers, Chris --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
-- -------------------------- 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.
Oliver Dial 1.pdf
Description: Adobe PDF document
--------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
