I am not sure to understand Zarbula and Indian circle methods
but perhaps this can help for your last question.
I know this relation is validated :
sin (D) = tan (X) / tan (L)
D = wall declination
X = angle between the equinoctial line and an horizontal line
L = Latitude
But I am not
Hi John,
It is back to the basics on this one: Waugh, Chapter 10, Page 79, Verse 1 to
4. The concepts of Sub-style Distance (SD), Sub-style Height (SH),
Difference in Longitude (DL) and Angle with the Vertical (AV) so well
developed in Waugh, are not evident in the computer programs that we now
