Monday, March 03, 2008

Benchmark M13

[click image to enlarge]

This U.S. Geodetic Benchmark is located on the property of a famous Quincy landmark in the Historic District of Quincy Center. All across the continental U.S. as well as in Alaska and Hawaii there is a network of survey monuments which are bronze disks like the one pictured here about 8 to 10 cm. in diameter set in rock or permanent structures. The exact number can only be guessed at, but they have been placed in all kinds of locations from city sidewalks and bridges to remote ridges and mountain tops. These have been set by surveyors beginning in 1879 and are the basis for horizontal and vertical control (measuring elevation) for all the physical mapping done in the US.

Come back tomorrow and Wednesday and I'll show you more of the Quincy landmark where I found this Benchmark. Have you spotted any "benchmarks" where you live?

6 comments:

Sailor Girl said...

Beautiful! It's the kind of photo I love!!!

Sailor Girl said...

(I'm not sure if we have this kind of benchmarks, but I will ask)

Jim said...

I have never seen anything like this, I wonder where theres one close to me?

George Townboy said...

This is awesome! I'm getting an education on your blog!

Marie-Noyale said...

It's always nice to learn something new...
I like a very nice picture with an interresting subject.
I will definitly look closer now.. un oeil averti... and I will let you know if I find anything.

Jana said...

Great photo. I have never seen a benchmark before.