The Circle

[NGS Surveyor]

I just had an article (that I wrote some time ago) posted onto the NGS web site. The article discusses the USC&GS survey of the 1000 foot radius circle around the U.S. Naval Observatory in the 1890’s. Here is the link: http://www.ngs.noaa.gov/web/about_ngs/history/THE_CIRCLE_V2.pdf

 

Enjoy,

GeorgeL

NGS

[ArtMan]

Thanks for posting this, GeorgeL!

 

I lived in DC for decades and probably drove along this stretch of Mass. Ave. hundreds of times and never gave it a thought.

 

The Naval Observatory moved to its present quarters in 1893. The previous location, on 23rd Street near the State Department headquarters and the Lincoln Memorial, had become unsuitable, in part because of noise and pollution. The move out to the present site in what was then pretty much the country — although the triangulation diagram does show a platted subdivision just outside the 1000' radius — was the equivalent today of putting an astronomical observatory on a mountaintop in Chile.

 

-ArtMan-

[Bill93]

That was a neat exercise but, other than the fact that they could, was there a practical reason for doing it to such precision?

 

For purposes of keeping away traffic and development, typical land survey tolerances of the time at perhaps 1:5000 +0.1 ft or so would have been quite adequate.

[+GEO*Trailblazer 1]

The Circle good read.

 

You think that it might also have something to do with this?

USNO Master Clock

 

Something that has always puzzled me was that Time and the Circle are both in Degrees,minutes and seconds.

OH well some things are yet beyond my comprehension.

Makes it fun to always look forward to learning something new.

 

Thanks

Hope everyone is having a good Holiday Season and good to be back from a long dry spell.