On Tue, 25 Jan 2011, John Pickard wrote:
If you need to check days of weeks for arcane dates, JoneSoft Date Calculator
is a free program that will give you the day of the week for just about any
date, and the number of days between two specific dates.
You only need about two lines of code to
Calendar math is an exercise in modulo arithmetic. See
http://www.gpsworld.com/gnss-system/innovation-gps-numbers-9741?page_id=5
for a peek into the topic.
-- Richard Langley
Quoting Tony Finch d...@dotat.at:
On Tue, 25 Jan 2011, John Pickard wrote:
If you need to check days of weeks for
Greetings, fellow dialists,
I seek enlightenment. I understand that both analemmatic dials and the
secondary dials of double horizontals are azimuth dials and both are
based on the stereographic projection . The time curves on the double
horizontal dial are multiple and dependent on the date
It seems to me you could consider the Capuchin dial variations, including the Navicula Venetiis, as altitude dials with a moving element. It's not a gnomon in the classic sense, but you do set the suspension point for the thread to the date.
Jim
James E.
hi Frank,
two years ago I designed a variant of the shepherd's dial so it became
universal (for any latitude).
The moving gnomon is curved (the curve is an astroid) and it may move up and
down and also around the dial.
The gnomon (the tail of the rooster, the crest and the beak are decorative)
In message 4d3ef531.1090...@zooplankton.co.uk
Frank Evans frankev...@zooplankton.co.uk wrote:
Almost every possible form of dial seems to have been devised already
but I have not come across an altitude dial resembling an analemmatic
dial in that the gnomon is moved with the
Dear Frank,
You say:
I have not come across an altitude dial
resembling an analemmatic dial in that the
gnomon is moved with the seasons and the
time curve is a single ellipse.
One interpretation of what you seek is to
have a dial on a vertical wall where the
gnomon is horizontal (and
Frank, you can use Orologi Solari to design an analemmatic vertical dial like
the one you describe.
See the attached example.
Greetings.
Gian Casalegno
http://digilander.libero.it/orologi.solari/
Messaggio originale
Da: frankev...@zooplankton.co.uk
Data: 25/01/2011 17.07
A:
Hello Frank,
all altitude sundials use only the Sun’s altitude.
Since the altitude is measured on a vertical circle movable with the
Sun, a sundial that bases its action on it has to be movable or to have
some movable part around the vertical axis: in general the whole sundial
can rotate
Hi Frank and all,
Yes, the Portuguese National flag has an armillary sphere hidden behind the
crest. The national flag for Brazil also incorporates an armillary sphere, the
mother of all sundials. Interpret or project the armillary as you wish to
create many forms of sundials. The armillary
The Australian national flag does not show a sundial but it is of astronomical
interest as a stellar flag. It shows the Southern Cross and another star to the
lower left. When visiting Australia, I would often ask about this single star
on the left. Everyone knew about the Southern Cross but
Dear Gian Casalengo,
Thank you for your interesting example...
...you can use Orologi Solari to design
an analemmatic vertical dial like the one
you describe.
I am glad we get the same answer!
Gianni Ferrari is quite right...
... Analemmatic are never altitude sundials,
even if they are
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