Apologies for this non-sundial question, but I do hope someone can help.
I've always been under the impression that Latitude/Longitude is a universal
and unambigious method of indicating a position on the earth but now I am
not so sure
In South-Africa, the National survey system is based on
John Carmichael writes:
I have a section which tells how to tell time by using moonlight and a
sundial. I provide a table of corrections from which the time can be
estimated if one knows the age (the phase) of the moon.
One question though: Is it nessary to correct moontime with the
I would appreciate any reference to someone in the UK who is qualified to
make a reproduction of a mariner's astrolabe from the 15th century from
drawings. Such a device would be made of a solid wood disk with a brass
edge and a brass alidade. The reproduction is for a BBC documentary.
Best
There's a difference between astronomical latitude and longitude and geodetic
latitude and longitude. Prof. Charles Merry at the University of Cape Town
should be able to help you out with the specifics of geodetic datums used in
South Africa: [EMAIL PROTECTED]
-- Richard Langley
Professor of
