I’ll go ahead and crank up the old cliché generator. See if you can select the one you think would be most appropriate to the current situation: I’m like a dog with a bone; I’m pulling a thread from the sweater; I’m beating a dead horse, or all of the above.
The American Meridian continues to bedevil me. We’re trying to organize an American Meridian Gathering of Circulars.[1] Right now I’m planning to wait until after the holidays. That’s because it’s a busy time of the year and also because it will provide Catholicgauze of Geographic Travels an opportunity to participate. He is about to leave on a trip to Afghanistan.
Problematic Shifting
I think a number of readers also had similar nagging feelings about the meridian. We all recognized the problem occurs because the American Meridian shifted a small amount over time. It doesn’t make much of a difference when viewed from a distance.
Drill in closer, however, and the variation become readily apparent. I’ve drawn three possibilities for the American Meridian and colored the distance between the extremes. That creates a fuzzy area and a level of doubt. Go ahead, zoom in and check it out.
I have to wonder if everything falling within the shaded box might be considered the meridian. Those shifts happened over time so it could be any of those places at least theoretically.
Background
The American Meridian began in 1850 as a longitudinal line running straight through the dome of the Old Naval Observatory. It moved three blocks east, from 24th Street to 21st Street in 1855 (current 77°2’48.0″). Then It shifted again by 1897, back to the west but still a little east of the 1850 line (current 77°3’2.3″).
Additionally it changed a couple more times in the early 20th Century. However those events happened after August 22, 1912. So by then the United States had already adopted the Greenwich meridian and we can ignore them.
Wikipedia cites the American Ephemeris and Nautical Almanac and the Coast and Geodetic Survey for those longitudes. They are easy enough to drop into a Google Map and produce the images I’ve displayed on this page. Frankly I’m surprised at the amount of shifting that took place considering the importance of landmarks pegged to that line. That even includes several state boundaries! Granted most of that surveying happened during the period when the second line was in effect so maybe I shouldn’t be concerned. Even so, a three block distance seems to be fairly significant.
Maybe we should consider the American Meridian “Line” as being three blocks wide? Maybe exact precision wouldn’t be appropriate for our purpose — Happy Hour socializing? This would place loyal-reader Craig’s suggested gathering spot, Mackey’s Public House [now closed] directly atop the meridian.
This also means that I work within a genuine geo-oddity. The land where my office building stands today began in the eastern hemisphere of the American Meridian, then shifted to the western hemisphere, then shifted back to the eastern hemisphere in the period between 1850 and 1912.
This pleases me immensely.
12MC Loves Footnotes!
[1]Is that what we should call the regular readers of the Twelve Mile Circle? Anyone have a better suggestion?
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