Luke Coletti <[EMAIL PROTECTED]> writes:
> Below are some data that may help you, the calculation date is
> Jan 1 Noon UT, EoT values are in the form TA-TM. The discussion to date
> has been more about the variation of our orbit and Earth's alignment
> within, however all these events nee
Hi Ruby,
wellcome
Get the Sun's Azimuths from the South (Z),
Z=arctg(senH/(senL*cosH - cosL*tgD))
where
H hour angles
L latitude
D Sun'declinations
the seven D angles are
0, 11.475, 20.155, 23.443,
-11.475, -20.443 and -23.443
The shadow points on the hour lines (H) are away from the
Radia
Ruby,
Sorry
The seven Sun Declination angles are
0, 11.475, 20.155, 23,443, -11.475, -20.155 and -23.443
I suggest to use mean values or take data
from software on those days when the EoT is near zero
jorge
> Can anyone help with an instrument maker called (Michael?)
> Butterfield (around late 17th century)? Possibly two of them, e.g.
> father and son. It is suggested they worked in York (U.K). Any
> information welcomed.
Michael (or Michel) Butterfield was English.
About 1680 he settled in Pa
Ruby Bojorquez wrote:
> To all:
>
>Could someone please help a floundering beginner in the fascinating
> world of gnomonics? I have two questions.
>
> 1. First, what is the purpose of the horizon ring in an armillary
> sphere? and
>
> 2. How does one calculate the zodiac lines on a horizonta
Arthur,
Please investigate for us, in the mean time you might find the
following URL interesting.
http://www.magnet.ch/serendipity/hermetic/cal_stud/cassidy/err_trop.htm
Luke
