Jeb Riordan wrote:
> 
> Can anybody please supply me with a table showing the angles between the
> hour lines for a horizontal sundial situated at Lat 21deg 20 min N, Long
> 71deg 20 minW
> (Caribbean 575 miles  East South East of Florida USA).
> 
> Please also confirm that the angle of the gnomom should be 21deg20min from
> the horizontal.
> 
> Note1: I have searched all locations identified by Yahoo. All good
> information and pictures but no details other than a small computer
> generated diagram, which is OK.  However I need to be accurate and would
> prefer to construct the hour lines from a table of angles.
> Note2: I am new to Internet and even newer to sundials. I hope this is
> acceptable netiquette.
> 
> Thanks,
> 
>                         Jeb Riordan.

For local suntime, with XII when the sun is due south, calculate the 
angles z with     tan z = sin phi . tan t

phi = latitude
t   = hourangle

XII  t = 0
I    t = 15
II   t = 30

XI   t = -15
X    t = -30 and so on.

Fer J. de Vries
Netherlands

Reply via email to