Hello Patrick and all, I view this form of construction quite acceptable. The gnomon is in the meridian plane. The advantage is the gnomon angle is true in the meridian plane, the co-latitude. The disadvantage is setting the the "fold" angle. This angle is obviously the declination of the wall but not as easy to set as the orthogonal substyle distance and substyle height. If the gnomon is damaged and misaligned, the error is not as easy to see or correct with a folded dial.
My first vertical declining sundial used this technique. I didn't know any better. Perhaps such dials are similar naive attempts by amateurs. There are a couple of examples that I know of in Canada. The corner dials on the Sisters of Charity Motherhouse in Ottawa are a good example. See my recent analysis of these dials at "http://www.walkingshadow.info/Publications/Index.html"; and click on #3. This is #127 in the NASS Registry The three dials on a pillar in Kingston Ontario are another example. A picture is at "http://www.sundials.org/registry/canreg.htm"; also as #450 in the NASS Registry. Regards, Roger Bailey www.walkingshadow.info "Life's but a walking Shadow" -------------------------------------------------- From: "Patrick Powers" <[EMAIL PROTECTED]> Sent: Thursday, September 11, 2008 3:57 PM To: "Sundial List" <[EMAIL PROTECTED]> Subject: 'Folded' Gnomon Declining dials? > > There is an unusual East Declining Vertical Dial on the side of the > Cathedral (Catedral de Santa María de la Sede) in Seville (Sevilla) in > Spain. > > It has a gnomon which is 'folded' from the Noon line rather than being > placed orthogonal to the dial plate along the sub-style line as is more > usual,. This dial must decline by around 50 degrees to the East. > > As far as I know there is only one dial of similar construction here in > the > UK (it is SRN 1279 in Hertfordshire) - though there may be others - and as > a consequence this form of construction has in Britain at least, been seen > as a rather 'amateurish' form of design. > > However having found this dial in Seville the question arises: Is this > form of gnomon construction more common than I thought? Are there more > instances of this form of gnomon design elsewhere and have they been > produced by what nowadays would be regarded as 'professional' designers? > > The Seville dial and the one known in the UK may be seen at > > http://tinyurl.com/4x24my > > Many thanks for any comments > > Patrick > > > > > --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > > No virus found in this incoming message. > Checked by AVG - http://www.avg.com > Version: 8.0.169 / Virus Database: 270.6.20/1666 - Release Date: > 11/09/2008 7:03 AM > --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
