Helmut,
Yes, there are quadrants with straight hourlines.
In the bulletin of De Zonnewijzerkring nr 10, october 1981 an overview of
quadrants is given by Hans de Rijk.
He points to:
The Horarium Bilimbatum as published in Protomathesus by Fineus Orontius,
1532.
This is noted in Bobinger,
Helmut,
No idea why I didn't add the formulas but now they are.
Thanks for your remark.
Best wishes, Fer.
Fer J. de Vries
De Zonnewijzerkring
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http://www.de-zonnewijzerkring.nl
Home
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Eindhoven,
Hi John,
Yes, I know and this is why a suncompass works.
It's one scale of date with a number of ellipses for different latitudes
around it.
With one remark.
At higher latitudes the length shrinks and final to zero at latitude 90.
And look at the formula:
y = a cos phi . tan decl
a cos phi is
The email, CD, and print editions of the June issue
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Fer,
I just had one more look on your webpage with the information on analemmatic
sundials. Therefore my question: Why did you not include the formula for the
date points of the dial? I know, one can see that very easy from the images
there, but perhaps it would be of some help for some visitors
Hi Helmut others:
I'm sure you probably know this already, but one neat and helpful thing I
learned about analemmatic date line construction is this:
All analemmatic dials at every latitude and of every size use the same date
line; the only difference is in the length of the line which
Damn! You're right. I meant to say that. I got it backwards in my letter,
but at least I it's right in my head! Thanks for catching my slip up.
John
- Original Message -
From: Mac Oglesby [EMAIL PROTECTED]
To: John Carmichael [EMAIL PROTECTED]
Sent: Monday, June 02, 2003 2:04 PM
