Dear Frank
every sundial has an heliodrome but its limits change with the
orientation of the dial, its shape and other if it isn't plane.
I took a glance to the last sundials uploaded on Sundial Atlas in these
days and I found a photo that is right for us.
(IT16648, photo by Roberto Incerti)
The light brown area is the heliodrome of the sundial because it is
where one can read the Sun projection. The shadow of the gnomon (its
edge) cannot leave the heliodrome.
The heliodrome of the wall is more extended because its limits are wider
than those of the dial.
In the sky the heliodrom is among the apparent orbits of the Sun at
solstices and the horizon.
ciao Fabio
Il 17/03/2019 12:47, Frank King ha scritto:
Dear Fabio,
Many thanks for your most interesting
message to the list...
Years ago Nicola Severino found
'eliodromo' in a book of Athanasius
Kircher...
Can you provide a photograph of an
eliodromo? OR, perhaps, a photograph
of a suitable sundial with the region
of the eliodromo highlighted?
Frank
Frank King
Cambridge, U.K.
--
Fabio Savian
[email protected]
www.nonvedolora.eu
Paderno Dugnano, Milano, Italy
45° 34' 9'' N, 9° 9' 54'' E, UTC +1 (DST +2)
---------------------------------------------------
https://lists.uni-koeln.de/mailman/listinfo/sundial
