RE: Meridian alignments

[Sundials]

The recent correspondence on meridian alignments has been interesting but I agree with Andrew James that the 'da Vinci code' should have the health warning. How far back do we wish to go with the situation regarding the 'prime meridian'? Since the time of Ptolemy (the Almagest man) and through the medieval period a large number of positions have been used by all sorts of authorities - nearly all somewhere in the Atlantic Ocean, going through the Canaries, various distances to the west of the Cape Verde Islands, etc. Popes have got involved, usually trying to satisfy the competing claims of Spain and Portugal. Map makers, like Mercator, and Sovereigns, for their own national ends, all chosing their own. The 1880 date quoted is wrong. The Washington Conference of October 1884 agreed that the Greenwich meridian would henceforth be the prime meridian – with only San Domingo opposing and France and Brazil abstaining. The French still have what they regard(ed) as their prime meridian passing through the Paris Observatory – the brass line is still inset in a room at first floor level. The St. Sulpice line is interesting, like others elsewhere on the continent and in Britain, but were largely laid down for other reasons.   Tony Ashmore.   -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Andrew James Sent: 17 December 2004 10:40 To: Roger Bailey; f.pineau2; SUNDIAL LIST Subject: RE: alignment - Saint Sulpice   I think perhaps the double use of the word "meridian" lies at the root of this confusion. From its antecedent word meridies - the middle of the day - we see how it means a line for determining time of noon and that is local noon wherever it may be situated, be it Saint Sulpice, Bologna, or Durham. The use of a particular line of longitude where the Sun is at its highest, noon, at the same time, as a base for measurement or "prime meridian" is another matter, for that could be done without reference to the Sun at all, for example with the required North - South line being established by the stars from any suitably equipped place - London, Paris, Rome, Palermo ...   In this day and age perhaps "The Da Vinci Code" should have a very big notice on the cover warning that it is not entirely composed of verifiable facts! The curious thing is that (as I understand) there are already many books commenting on it and many reviewers - let alone members of the public - seem to accept its allegedly historical background and interpretations as more or less scholarly truth, however poorly they may stand up to scrutiny. I am sure, Roger, that you are not the only one to be confused by it but at least you can recognise an embellishment!   Andrew James     Roger Bailey wrote:   snip <<The Saint-Surplice meridian is a key element in the best selling novel "The Da Vinci Code" by Dan Brown. >>   snip <<This confused me as I expected the Paris Meridian to go through the Observatory of Paris ... The meridians are quite different but the novel brings them together. This is not the only fact embellished by the author to set the plot for his novel.>>     PRI Limited, PRI House, Moorside Road Winchester, Hampshire SO23 7RX United Kingdom   Tel:  +44 (0) 1962 840048 Fax: +44 (0) 1962 841046 www.pri.co.uk                    The Intelligent Metering Company This correspondence is confidential and is solely for the intended recipient(s). If you are not the intended recipient, you must not use, disclose, copy, distribute or retain this message or any part of it. If you are not the intended recipient please delete this correspondence from your system and notify the sender immediately. This message has been scanned for viruses by MailControl   -