Can you help me?
I buildt a horizontal sundial, with correction for longitude. I want
install it with no prior determination of true north.
At noon, when the sun is at the zenit, on the local meridian, I will point
the gnomom to true north (i'm at the southern hemisphere), just looking for
a point where the shadow cast exactly on the noon hour line. That's correct?
Supose I will install it on August 15, when the sun is 4 minutes 33 seconds
late with the local mean time. I ask: the exact moment to that is at local
mean time MINUS orPLUS 4 minutes 33 seconds?
Thank you in advance
Sergio Doret
