Mac, I suspect that if you aim the telescope at the sun then the hour circle will show the local time.
In Porter's (Scientific American) "Amateur Telescope Making," probably Volume I, there is a sketch of a sundial based on a spherical chemist's flask. As I recall, a lens in the neck was aimed at the sun which would be focused on the date on the analemma strip in the center. I was tempted to build one, but never did. Gordon Uber (who ground--and almost polished--a telescope mirror as a fifteen-year-old) At 04:45 PM 5/14/2007, Mac Oglesby wrote: >Hello Friends, > >The Summer 2007 issue of Vermont Life magazine contains a nice >article on Stellafane, a convention of amateur telescope makers which >convenes each summer in Vermont, USA. > >Prominent among its founders was Russell W. Porter, architect, >artist, mechanical genius, Arctic explorer, telescope maker, and >dialist. > >A sidebar features Porter's Garden Telescope, described as an elegant >combination of a sundial and a reflecting telescope. A replica is >being produced by Fred and Russ Schleipman of Norwich, Vermont. Point >your browser at: > >http://www.gardentelescopes.com/ > >(be sure to read the "History" and "About Us" pages) > > >Porter designed and produced several different cast bronze sundials. >Some may be owned by members of this List. > >My question is, how, exactly, does the elegant device pictured in the >magazine (and on the website) function as a sundial? > >Best wishes, > >Mac Oglesby > >(Who, 60+ years ago, was walking round and round the barrel, trying >to make a reflecting telescope mirror.) > > > > > > > > >--------------------------------------------------- >https://lists.uni-koeln.de/mailman/listinfo/sundial --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
