Details for Benchmark: HV3761
N 38° 54.969 W 077° 06.252 (NAD 83)
Coordinates may not be exact. Altitude is SCALED and location is ADJUSTED. (more info)
- In ARLINGTON county, VA View Original Datasheet
- TREE 2
- Marker Type:
- triangulation station disk
- in a boulder
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||Difficult Run posted a note for HV3761
This mark may have been found.
Recovered a 1/2" dia bronze shank protruding 1.5 inches out of the top of a 2 ft. by 4.5 ft. (approx) boulder at the river's edge.
GPS coords are:
N38' 54' 58.1' W77' 06' 15.2'
NGS coords are:
N38' 54' 58.135' W77' 06' 15.15'
The two coords are within 5.5 feet of one another!
Flagging tape wrapped around shank to aid in possible later recovery.
[Photos:]Closeup of Possible Station.
Shank is 1/2 in. in diameter and protruding 1.5 inches out of rock face. Quarter added for scale.
Possible Station As Viewed From The Shoreline.
Note the bank is covered with small rocks (spoils from a nearby quarry) as in the 1947 description.
Documented History (by the NGS)
|01/01/1935 by CGS (MONUMENTED)
|DESCRIBED BY COAST AND GEODETIC SURVEY 1935 (JHB)
STATION IS SITUATED ON A LOW SANDY POINT ABOUT 1-1/4 MILES SE OF CHAIN BRIDGE ON THE VIRGINIA SIDE OF THE POTOMAC RIVER. THE POINT IS COVERED WITH SMALL TREES AND UNBERBRUSH. THERE IS AN OLD STONE QUARRY BACK OF THE STATION. STATION IS ABOUT 3 FEET IN FROM HIGH WATER AND ABOUT 1-1/2 FEET ABOVE IT.
THE STATION MARK IS SET IN A DRILL HOLE IN A BOULDER ABOUT 12 INCHES ACROSS AT THE TOP AND EXTENDS INTO THE GROUND ABOUT 3-1/2 FEET. NO SUBSURFACE MARK WAS PLACED.
WITNESS MARK NO. 1 IS A NAIL ABOUT 3 FEET ABOVE THE GROUND IN A 6-INCH COTTONWOOD TREE.
WITNESS MARK NO. 2 IS A NAIL ABOUT 3 FEET ABOVE THE GROUND IN A 6-INCH SYCAMORE TREE.
HEIGHT OF LIGHT ABOVE STATION MARK - 1.5 METERS.
|01/01/1947 by CGS (MARK NOT FOUND)
|RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1947 (RMB)
STATION WAS NOT FOUND. AN EXTENSIVE SEARCH WAS MADE FOR THE WITNESS MARKS AND THE STATION. THE SANDY POINT REFERRED TO IN THE ORIGINAL DESCRIPTION IS NOW COVERED WITH SMALL ROCKS AND IT IS POSSIBLE THAT THE WITNESS MARKS HAVE BEEN WASHED OUT BY FLOODS.
- The horizontal coordinates were established by classical geodetic methods and adjusted by the National Geodetic Survey in November 1994.
- The orthometric height was scaled from a topographic map.
- The Laplace correction was computed from DEFLEC99 derived deflections.
- The geoid height was determined by GEOID99.