Benchmark?

[+CluelessnLuV]

Hi all. Really new to this Benchmarking stuff, so need help right off the bat. While in DC (Embassy Row), found this benchmark

or (seems to have a problem posting the link from skydrive) look at the Picture Here. Geodesic reference Point 4930

The location is approximately: N 38° 55.356 W 077° 04.427 (on google maps you can even see the marker HERE)

 

Any ideas as to what it really is? Checked Waymarking already for this location and also came up with nothing.

 

Thanks

CluelessnLuv

Edited June 27, 2011 by CluelessnLuV

[AZcachemeister]

Definitely an interesting object!

 

Reminds me of the missile-alignment pylons here in AZ.

 

Are there any missile silos nearby?

[68-eldo]

I don’t think so but the Naval Observatory is a about a half mile away.

 

Did you notice the degree markings around the outer ring? 180 degrees is at the top of the picture.

[mloser]

I looked around to see if it could be a reference mark for any of the Naval Observatory marks but it doesn't seem likely. None of the marks on the property referenced anything at that distance or angle.

 

I also looked up DC geodetic marks on the DC GIS site and didn't come up with anything.

 

It is definitely an odd mark, especially with that ring of degree markings around it. Note that they are REVERSE of a normal compass too. My first thought is that they are that way to show backsight direction to some other monument, but that is just a guess, and to be honest, a surveyor would naturally reverse the directions for a backsight, so maybe not.

The two pinholes in the top might there to mount some sort of instrument, but I am not sure what.

 

Also, and this REALLY puzzles me, it says GEODESIC marker, not GEODETIC marker. I have no thoughts about what that could mean. Geodesic is a math concept and has to do with the shortest line between two points in space, hence the geodesic dome made up of triangles (straight lines). Its root is "geodesy", which refers to measuring size and shape of the earth, so we get back to surveying a bit, since, according to the all-knowing Wikipedia "in the original sense, a geodesic was the shortest route between two points on the Earth's surface, namely, a segment of a great circle." I just have no memory of ever seeing that in reference to survey markers. Maybe it IS related to something at the Observatory.

 

Anyone else have any thoughts?

[TillaMurphs]

I am bumping this one in the hope that it won't be forgotten. This is quite a mysterious object.

 

I wonder if ArtMan or foxtrot_xray have any ideas? Don't they have ties to the DC area?

[foxtrot_xray]

I'm in Silver Spring, just north of DC. I have this on my 'gotta find' list, so that the next time I'm in DC I can get a better picture and see it first-hand. Dunno w hen that may be yet, however.

[foxtrot_xray]

Not really an update, but a friend sent me this link, and I was surprised to see Dave Doyle strike again! Granted, this was back in the early '90's, when Dave must have been in training for his chief surveyor position he's in now.

[+CluelessnLuV]

I will be back in the area soon so i can try and take a better picture and coordinates reading. As for missile silos nearby.... there is a Russian Federation Embassy property that starts only couple hundred feet from there

Edited July 14, 2011 by CluelessnLuV

[TillaMurphs]

I'm in Silver Spring, just north of DC. I have this on my 'gotta find' list, so that the next time I'm in DC I can get a better picture and see it first-hand. Dunno w hen that may be yet, however.

 

I will be back in the area soon so i can try and take a better picture and coordinates reading.

 

CluelessnLuv or foxtrot_xray,

 

Did either of you make it back?

 

This mark really has me intrigued. I gotta know what this is.

 

[with hands on hips in best stern voice]: Don't make me come over there you two!

[kayakbird]

[with hands on hips in best stern voice]: Don't make me come over there you two!

 

and you are close enough to do it!?! MEL

[+frex3wv]

I have no clue what it is - but my sense is that SOMEONE on here does and will tell us in time - that has been my expereince with all the fine folks on this particular forum. They are very nice AND VERY SMART!

[TillaMurphs]

[with hands on hips in best stern voice]: Don't make me come over there you two!

 

and you are close enough to do it!?! MEL

 

Well, it's a long walk. However, I have the Reference Mark arrows to show me the way. Link courtesy of Bill93

[kayakbird]

Well, it's a long walk.

 

Only 594,754.49 Smoots, bearing 042.87 degrees from your last log note. MEL

[TillaMurphs]

Well, it's a long walk.

Only 594,754.49 Smoots, bearing 042.87 degrees from your last log note. MEL

 

I'm not sure which is worse?: that you actually took the time to calculate that or that I actually took the time to confirm whether or not you did actually calculate that.

 

What is really important here is that foxtrot_xray has not interrupted his vacation to go check on this.

 

I think we can give CluelessnLuV a break because they are, well... clueless in luv. However, Mike really has no excuse. He should be able to take a smartphone photo with his new app and it should be capable of answering our question.

[foxtrot_xray]

 

I'm not sure which is worse?: that you actually took the time to calculate that or that I actually took the time to confirm whether or not you did actually calculate that.

 

What is really important here is that foxtrot_xray has not interrupted his vacation to go check on this.

 

I think we can give CluelessnLuV a break because they are, well... clueless in luv. However, Mike really has no excuse. He should be able to take a smartphone photo with his new app and it should be capable of answering our question.

What is this, pick on Mike day? I'm in Ouray, Colorado, used my little app all the way through Nevada, the corner of Arizona (at the Dam) and Utah. It worked brilliantly. Tomorrow we start research and packing to get to Crown Jewel, Silver King, and Gold King Mines, as well as a few other smaller mines out south of us.

 

I'll get over there to look at this thing, honest! I'm as curious as anyone. Just gimme some time.

[TillaMurphs]

I'm in Ouray, Colorado, used my little app all the way through Nevada, the corner of Arizona (at the Dam) and Utah. It worked brilliantly. Tomorrow we start research and packing to get to Crown Jewel, Silver King, and Gold King Mines, as well as a few other smaller mines out south of us.

 

Mike,

 

Sounds like a great trip. I hope you continue to have a wonderful time. By the way, we really like your app and agree that it works brillantly.

 

Have fun,

 

The TillaMurphs

[TillaMurphs]

I'll get over there to look at this thing, honest! I'm as curious as anyone. Just gimme some time.

 

I will be back in the area soon so i can try and take a better picture and coordinates reading. As for missile silos nearby.... there is a Russian Federation Embassy property that starts only couple hundred feet from there

 

CluelessnLuv or foxtrot_xray,

 

Did either of you make it back?

 

I gotta know what this is.

[foxtrot_xray]

CluelessnLuv or foxtrot_xray,

 

Did either of you make it back?

 

I gotta know what this is.

 

..Wow, I had forgotten about this! D'oh!

And with my luck, I leave in a week to head out to California.

 

However, I made a note of this thread, and when I get back in town the second week in September, I'll make it a lunch trip and head down that way. Promise.

[foxtrot_xray]

Hey guys - Got come closeups of the station. Upon studying it, it's about 6 inches round, with a raised flat surface in the middle (raised about 3 inches), with two open holes on it. On the top raised part around the edge is "Geodesic Reference Point 49130". On the bottom ring are degrees of rotation, north (0, 360 degrees) is at the damaged bolt.

It's been run over several times with a lawnmower, and two of the mounting bolts are missing. It's loose, and if you tap on it, it IS hollow. (My gut tells me it's more hollow that it should be - meaning there's an empty space under in in the cement, but I couldn't verify.)

 

Enjoy!

[Bill93]

Counterclockwise azimuth?

[TillaMurphs]

Good Job Mike!

 

THANK YOU!!!!!!

 

Curiouser and curiouser.

 

Doing a web search for "Geodesic Reference Point" brings up very little and nothing helpful. The way this is stamped (with a number) somewhat implies that there would be more than one of these. But alas nothing shows up in a search.

 

Was 0 degrees pointing north? Any idea if the center was designed to be permanently stationary? – or, was it designed so that you loosened up the bolts and placed a device in the two holes and then rotated the device? (As mloser questioned in his very well thought out and researched post above).

 

Seemingly being such an orphan item maybe it is related to the Naval Observatory.

 

I wonder if Dave Doyle or NGS Surveyor would have any ideas on this?

[Bill93]

The reverse azimuth might imply that the center was fixed and the outer circle would have something attached and rotate to read the azimuth at an index mark on the center piece. That would yield normal azimuth values. But I don't see the index mark and can't tell if anything rotates.

[foxtrot_xray]

Hey guys -

No, nothing moved that I could tell. (Or, if it DID move, it no longer does.) 0-degrees did point north. I also forgot to mention that I believe(*) the top was NOT flat, it was angled. Whether this was because it's gotten hit by a lawnmower, or made that way, I cannot say. I did walk up and down the street to see if there was another one, and I didn't find any.

 

(*) - The picture I took of it on the ground, to get a profile, was not saved correctly - it got corrupted.

[ArtMan]

Interesting object, that's for sure. I like mloser's idea that the holes in the top part are to mount an instrument.

 

foxtrot xray, you might consider contacting the public affairs people at USNO, to see if they might point you to someone who might help.

 

-ArtMan-