Thank you, Luke. Very nice. How can those folks, 2 centuries ago, measure to 2+ parts per 10K, and I can't even get the sign of the "error" right? Hmm. (Maybe it would be best NOT to answer the above question!) *LOL* Cheers, Tom
Luke Coletti wrote: > Hi Tom, > > I'm not exactly sure how or when it was later determined that the > Earth > is really larger than what was surveyed (1792-1799) by the French but my > guess is that satellite data was the key. Also, as Gorden mentions, the > survey did not involve the full 90deg of the quadrant but instead only > about 10degs of latitude from Dunkirk (through the Paris Observatory) to > Barcelona, both of which are at sea level. I'm not sure if the French > incorporated the fact that the Earth is not a perfect sphere. My > reference, "The Science of Measurement - A Historical Survey" by Herbert > Arthur Klein, mentions that instead of the standard quadrant being > 10^7meters (which I assume was originally arbitrarily assigned and the > meter length itself being found via the survey measurement) it is really > 10,002,288.3 meters in length (2+ parts in 10,000). > > Best, > > Luke > > Tom wrote: > > > SNIP > > > > I wonder if this is where Luke gets the 0.023% figure? Does it imply that > > Delambre and Me'chain (under the supervision of Jean-Charles chevalier de > > BORDA?) > > measured the quadrant to be 9,997.3 km instead of 10,000 km?
