Dear Louis, Thanks for the longitude information (below) but could you add the longitude for the BIPM that I believe is also slightly west of Paris.
Thank you, Pat Naughtin CAMS Geelong, Australia on 2002-12-03 22.25, Louis JOURDAN at [EMAIL PROTECTED] wrote: > At 23:16 +0000 02/12/2, David Jones wrote: >> Hi, >> >> I'm trying to find out the longitude of the Dunkirk-Barcelona meridian >> along which measurements were made in 1739-40 (Lacaille and J Cassini) >> and 1792-98 (Mechain and Delambre) in order to define the metre. >> >> Some authors wrongly state or assume that this was the same as the Paris >> meridian which goes through the Paris Observatory. In fact, although the >> meridian along which the measurement was taken passes very close to >> central Paris, it does not pass through central Paris. >> >> I'd be very grateful if someone could let me know (or direct me to a >> source where I can find) the exact longitude of the Dunkirk to Barcelona >> meridian; or identify a building or site through which it was chosen to >> pass. I'm curious as to why they didn't choose the meridian going >> through the observatory. > > Paris (Observatoire) longitude : 2� 50' E > Dunkirk longitude : 2� 23 ' E > Barcelona longitude : 2� 20' E > > The "Dunkirk-Barcelona" meridian effectively did not pass through > Paris (Observatoire) but was very close. Necessary corrections were > easily made by triangulation calculation. > > Louis >
