Details for Benchmark: MY2425
N 42° 20.839 W 071° 04.972 (NAD 83)
Coordinates may not be exact. Altitude is VERTCON and location is ADJUSTED. (more info)
- In SUFFOLK county, MA View Original Datasheet
- Marker Type:
- triangulation station disk
- mat foundation, concrete slab, etc.
- May hold, but of type commonly subject to surface motion.
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Documented History (by the NGS)
|01/01/1965 by MAGS (MONUMENTED)
|DESCRIBED BY MASSACHUSETTS GEODETIC SURVEY 1965 (GFC)
THE STATION IS ABOUT 2.5 KM (1.5 MI) SOUTHWEST OF BOSTON CITY HALL AND ABOUT 2.9 KM (1.8 MI) SOUTHEAST OF CAMBRIDGE CITY HALL. OWNERSHIP--PRUDENTIAL INSURANCE COMPANY.
TO REACH THE STATION FROM THE STATE HOUSE IN BOSTON, GO SOUTHWEST ON BEACON STREET ABOUT 2.0 KM (1.3 MI) TO GLOUCESTER STREET. TURN LEFT AND GO SOUTH ABOUT 0.4 KM (0.3 MI) TO BOYLSTON STREET. TURN LEFT AND GO EAST ABOUT 0.2 KM (0.1 MI) TO THE PRUDENTIAL INSURANCE COMPANY BUILDING ON THE RIGHT. TURN RIGHT AND GO TO THE LOWER GARAGE LEVEL AND THE SECURITY OFFICE. ARRANGE TO TAKE THE FREIGHT ELEVATOR TO FLOOR NUMBER 51 AND THE STATION.
THE STATION IS MARKED BY A MAGS DISK STAMPED---PRUDENTIAL 1965---, AND IS SET IN THE CONCRETE DECK AT THE NORTHWEST CORNER OF THE BUILDING, BETWEEN THE PARAPET WALL AND THE STEEL RAILS OF THE WINDOW WASHING MACHINE.
REFERENCE MARK 1, IS A MAGS DISK STAMPED---PRUDENTIAL RM 1 1965---, AND IS SET IN THE CONCRETE DECK AT THE NORTHEAST CORNER.
REFERENCE MARK NO. 2 IS A STANDARD MAGS DISK STAMPED---PRUDENTIAL RM 2 1965---, SET INTO THE CONCRETE DECK AT THE SOUTHWEST CORNER.
HEIGHT OF LIGHT SHOWN WAS 1.5 METERS ABOVE THE MARK.
DESCRIBED BY R.A.KELLER, MAGS.
741110 ALL THE MARKS WERE RECOVERED IN GOOD CONDITION ON THIS DATE. W.J.KENNEDY, MAGS.
- The horizontal coordinates were established by classical geodetic methods and adjusted by the National Geodetic Survey in June 1998.
- The NAVD 88 height was computed by applying the VERTCON shift value to the NGVD 29 height (displayed under SUPERSEDED SURVEY CONTROL.)
- The Laplace correction was computed from DEFLEC99 derived deflections.
- The geoid height was determined by GEOID99.