In January I found a nautical chart published by the French Royal Navy in 1772. The chart covers southern England, the English Channel, France, Portugal, Spain, the western Mediterranean, and the Barbary Coast.
Studying the chart more closely, I noticed that longitude was measured east and west of the Meridian of Paris, with the Observatory of Paris defining the zero meridian.
Recalling from Charles H. Cotter's book "A History of Nautical Astronomy" that the governments of the world did not agree to use Greenwich as the Prime Meridian until 1884, I decided to do a little more research.
The U.S. Government convened an "International Conference for the purpose of fixing a prime meridian and a universal day" in Washington in October 1884. The protocols of the proceedings can be found at:
http://www.gutenberg.org/files/17759/17759-h/17759-h.htm After shoveling snow this morning in Annapolis, I sat down and read this document.
It reads almost like a novel. An American delegate prematurely proposes Greenwich as the prime meridian on the first day of the conference, only to be rebuffed by the French delegation arguing in favor of a "neutral initial meridian," running through the Azores or the Bering Strait. (Evidently, the French knew there was insufficient support for using the meridian of Paris as the prime meridian but tried to prevent England from obtaining that honor.) The British, at first, remained relatively quiet, knowing that they had the strongest hand -- and the support of the Americans. Over seventy percent of the world's shipping fleet (measured by tonnage) was already using charts indicating Greenwich as the zero meridian, and Great Britain published far more nautical charts than any other country. Still, at that time, there were numerous charts published by numerous countries with a dozen or more "initial meridians" -- Greenwich, Paris, Washington, Berlin, Rio de Janeiro, Ferro Island, etc. One can only imagine the headaches this caused navigators.
After long debates mixing "science and sentiment," the delegates voted overwhelmingly in favor of Greenwich as
the Prime Meridian. France took the high road and abstained, rather than voting against the resolution. Next there were tedious, scientific (and not-so-scientific) deliberations about whether meridians of longitude should be measured 360 degrees from west to east, 360 degrees from east to west, or 180 degrees both east and west of the Prime Meridian. We all know the result of that debate.
Finally, the conference addressed the matter of a "universal day," debating the pros and cons of placing the international date line (a term not used during the conference) at the Greenwich meridian or the "anti-Greenwich meridian," i.e., 180 degrees opposite the Greenwich meridian. We all know how that debate turned out, too. The conference also touched upon the need to promote the use of the metric system, a French invention, apparently to soothe the wounded pride of the French delegation, but the conference was not empowered to make any formal recommendations on that matter.
As a former diplomat and an amateur navigator, I found this account of the Washington Conference fascinating. Many of the basic navigational concepts we take for granted today remained unsettled and hotly contested until 1884. The Washington Conference brought a semblance of order out of chaos.
Jackson
