Hi Phil, The shadow forming edge of the Gnomon must be parallel the the axis of the earth. To do that the shadow forming edge of the Gnomon is set to be the same as your latitude. The only difference in the southern hemisphere is the the tip of the Gnomon is facing South. While in the Northern hemisphere it faces to the North. Doing this keeps the shadow forming edge of the Gnomon parallel to the axis of the earth, whatever the location.
Roderick Wall, Melbourne Australia. On Nov 16, 2015 9:37 AM, Phil Dorman <[email protected]> wrote: > > Hi Everyone, > > > > I joined this list because I have a specific question which I can’t find a > definitive answer to. > > > > I want to install a sundial at Perth WA Australia which is pretty close to > 32deg South latitude. > > From what I can determine that means the Gnomon should be 32deg above > horizontal. > > Or is that just for the Northern Hemisphere ?? > > > > As I move North in Australia the Latitude number gets Smaller > > Eg Latitude of Brisbane QLD (further North) is 27.46deg > > So presumably the Latitude at the Equator would be Zero ! > > Which would mean a sundial Gnomon at the Equator would be Horizontal ie Flat > on the Ground > > Which of course would not work. > > And at the South Pole it would be Vertical 90deg from Horizontal and also > would not work since there would be no ground for the shadow to fall on. > > > > So. Am I correct to put it at 32deg from Horizontal for Perth WA or not ? > > > > Phil Dorman /:~)> > > Machinery Appreciation & Transport Engineering Society > 946 Wattagan Crk Rd > Watagan NSW 2325 > > 0419 501285 > > > >
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