This is a MapHist list message (when you hit 'reply' you're replying to the whole list) o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o +
Since the rotational axis of the earth has changed with time, but I have no idea if there is any history of it in terms of the not-so-distant past, I ask: Were I measuring latitude with a gnomon in Roman Britain along a line of 0 deg longitude during the period 50-150 AD, what would be the difference in my calculated latitude versus current standard latitude? A formula for conversion accounting for longitude? The lines of "latitude" derived from the British section of the Ravenna Cosmography are south of expected by about 1/6 degree. How accurately can we expect a gnomon to measure latitude? -- Tom Ikins The Roman Map of Britain http://www.romanmap.com _______________________________________________ MapHist: E-mail discussion group on the history of cartography hosted by the Faculty of Geosciences, University of Utrecht. The statements and opinions expressed in this message are those of the author and do not necessarily reflect those of the University of Utrecht. The University of Utrecht does not take any responsibility for the views of the author. List Information: http://www.maphist.nl Maphist mailing list [email protected] http://mailman.geo.uu.nl/mailman/listinfo/maphist
