Interesting one in Rue Montmartre https://www.instagram.com/reel/Cj0hS2JIPQV/?igshid=YmMyMTA2M2Y=
On Wed, Oct 26, 2022, 11:58 Werner Riegler <werner.rieg...@cern.ch> wrote: > Dear John, > > I know this object as “Horizontoscope". > http://www.horizontoscop.com/eng/index_eng.html > > I bought one recently after reading about it in one of Helmut > Sonderegger’s articles, where he gives the math of it. > > https://www.herzog-forsttechnik.ch/wp-content/uploads/2022/08/Sonnenkompass_Flyer-2022.pdf > > It’s quite interesting how the hyperbolic surface makes the image > independent of the height between the observing eye and the device. > > There is a german wikipedia entry. > https://de.wikipedia.org/wiki/Horizontoskop > > Maybe someone from the sundial list can produce an english entry with the > theory. It’s a nice device ! > > best regards > Werner > > > > > > On 26 Oct 2022, at 02:45, John Pickard <john.pick...@bigpond.com> wrote: > > Good morning, > > Has anyone come across this dial-related device? > > > https://picclick.co.uk/ARCHITECT-TOOL-Window-SUNLIGHT-SUN-ELEVATION-Enraf-144741549298.html > > Cheers, John. > > Dr John Pickard. > > --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > > --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial > >
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