Here is what wikipedia says, regarding formulas for Reclining-Declining
sundials:
In fact it is only in the last decade that agreement has been found on the
correct hour angle formula for this type of dial. [...] Previous formulae
given by Rohr and Mayall are not correct.
That wikipedia
Additionally, Mayall Mayall's formula (shown in the notes at the bottom
of the wikipedia Sundial article) for the angle between the substyle and
the line for noon, gives the right result for:
Lat = 51.5
Inclination = 45
Declination = 45 degrees left of south
Michael Ossipoff
I should add that the correct result described above, with Mayall
Mayall's formula for the angle between the substyle and the line for noon,
is gotten when the decline-direction (D) is measured from north.
So D is the azimuth that the dial is facing.
Michael Ossipoff
Sorry, I didn't intend to start new thread; I'm adding something to my
Mayall Mayall question-post:
First, I thank Simon for the answer and link.
I've decided to divulge the reason for my question about Mayall Mayall:
The wikipedia Sundial article says that Mayall Mayall, and Rohr as well,
