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Details for Benchmark: MZ1808

N 42° 14.511 W 072° 38.890 (NAD 83)

Altitude: 1200

Coordinates may not be exact. Altitude is VERTCON and location is ADJUSTED. (more info)

Location:
In HAMPDEN county, MA View Original Datasheet
Designation:
MOUNT TOM
Marker Type:
bolt
Setting:
in rock outcrop
Stability:
Most reliable and expected to hold position/elevation well.

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who ha alover the place with this guy

Easy enough to find, even with the nearby reference markers destroyed or missing.

Found 05/06/08 @ 11:04 am

This recovery was a joint effort of Dave (ddnutzy) and myself. See also ddnutzy's log for this station which has additinal photos.

We spent a good part of the Patriot's Day weekend in Massachusetts searching for old triangulation stations. We were particularly looking for those used in the early triangulation which took place from the 1830s to the 1860s and which became part of the Eastern Oblique Arc.

This was one of the primary stations and the original copper bolt set in 1862 is still intact. It is on the ledge on the top of Mount Tom and is under several inches of crushed stone which has been spread over the summit area. Until a few years ago, this mark was in front of an air beacon tower and next to an equipment building. These structures have been removed which greatly enhances the summit site.

The station and 4 reference marks (RM1, RM2, RM4 and RM5 - 1937 Eccentric) were recovered. We could not find RM3 or the 1936 Eccentric. We also found MZ1807 "Mount Tom Borden" an 1835 copper bolt. It was found 18" underground. See [url=http://www.geocaching.com/mark/details.aspx?Pid=MZ1807]MZ1807[/url]. We also found an undocumented stub of a disk about 10m further out on the line to RM5, with remnants of a large painted white cross.

See station [url=http://www.geocaching.com/mark/details.aspx?Pid=MY4858]MY4858[/url] for maps from the C&GS Special Publication No. 76 "Triangulation in Massachusetts" (1922) which shows all the primary stations, and also a screen shot from a Google Map I constructed of the same stations which also shows the connection to the Eastern Oblique Arc.

Here is a link to the interactive Google Map for this triangulation where each station can be clicked for a detailed map and other information: [url=http://members.bellatlantic.net/~vze2h6gy/papabear/BM_Station_GMap.html#FILE=Mass_Old_TriStations.js&index=triangle&t=ter&width=960&height=720&title=1][b]Interactive Map[/b][/url]

Here is a link to the special publication: [url=http://docs.lib.noaa.gov/rescue/cgs_specpubs/QB275U35no761922.pdf][b]Special Publication No. 76[/b][/url]

And lastly, Here is a link to Holograph's Benchmark Wiki site explaining the Eastern Oblique Arc: [url=http://www.holoscenes.com/cgi-bin/moin.cgi/EasternObliqueArc][b]E.O.A.[/b][/url]

[Photos:]
photoMZ1808 Mount Tom, Holyoke, MA
Area view of the station. The concrete structures are the foundations of the old air beacon tower.
photoMZ1808 Mount Tom, Holyoke, MA
Diagram showing the relative positions of the marks we recovered.
photoMZ1808 Mount Tom, Holyoke, MA
Close up of the station mark, a copper bolt set in 1862. It was under 2 - inches of crushed rock.
photoMZ1808 Mount Tom, Holyoke, MA
The shank of the disk for RM1. This was to the south of the station on the ledge near the edge.
photoMZ1808 Mount Tom, Holyoke, MA
Shank of the disk for RM2, northwest of the station.
photoMZ1808 Mount Tom, Holyoke, MA
RM4, east of the station.
photoMZ1808 Mount Tom, Holyoke, MA
RM5: 1937 Eccentric, north of the station
photoMZ1808 Mount Tom, Holyoke, MA
Close up of RM5: 1937 Eccentric.
photoMZ1807 Mount Tom Borden
Closeup of "Mount Tom Borden" a copper bolt located 18" underground, about 11 feet from this station. See log for MZ1807.
photoMZ1808 Mount Tom, vintage documentation
Description of this station from the USCGS Special Publication No. 76 (1922).

Found two bolts, one stem (RM1),RM4 and RM2 with Papa Bear.

[Photos:]
photobolt 18" under surface
photoStation
photoRM4
photoRM1
photoBorden bolt benchmark monumented 1833
photoAnother RM

Covered with stone, still in good condition.

Had not seen it logged for a while so had it on my list. Found without work, just loose gravel covering it. Now see several have found it recently also.

[Photos:]
photoMt Tom Bolt
Nothing fancy- Just bolt & GPS

GPS today

RM1 42 14.503 072 38.901
RM2 42 14.516 072 38.894
RM3 NF
RM4 42 14.510 072 38.889
RM5 42 14.526 072 38.881 ECC
RM5N 42 14.529 072 38.877

[Photos:]
photoStation
photoSta. closeup
photoMZ1808RM1.jpg
photoRM1 closeup
photoRM2
photoRM4
photo RM5 Disc N of sta. S of original RM5
photoRM5 Original N of Disc rm5

Located this one as we were exploring the area around the towers & the M&M trail!

still there, found it just before some thunderstorms started moving in.

Benchmark recovered using the information provided in the 1965 description. The mark was located below 4cm of loose crushed stone just south of the old airway beacon tower.

At some point the original ordinal references were renumbered using standard RM designations but not described in previous recoveries.

RM 1 (SW) was recovered - disc is missing, original drill hole and arrow intact.
NNW (RM 2) recovered - disc is missing, shank in drill hole and arrow intact.
RM 4 (SE) recovered - square and arrow intact.

ENE (RM 3) and RM 5 were not searched for.

[Photos:]
photoStation MZ1808 Mount Tom
photoStation location south of beacon tower
photoStation MZ1808 RM 1 - SW
photoLocation of RM 1 - SW
photoStation MZ1808 NNW
photoStation MZ1808 RM 4 - SE
photoLocation of RM 4 - SE
photoLocation of NNW
photoStation and reference mark layout
N 42° 14.512 W 072° 38.893

Found in OK condition.

[Photos:]
photoMZ1808

Spent a day up on Mt. Tom and found this benchmark as well as others.

The benchmark is a little elusive but can be found with patience and a good measuring tape. I was also able to recover reference marks 1, 2 and 4. RM1 and RM4 are clearly marked; RM2 is in the open but not blazed like 1 and 4. RM2 is also missing the disk that was placed there some years back.

A storm was approaching before I could locate RM3 and RM5 as well as Mt. Tom Eccentric. RM3 looks easily findable but there is some vegitation covering the spot. I did not want to disturb the plantlife so I opted to dismiss it from my search.

BP

[last edit: 8/23/2002 1:59:28 PM PST]

[last edit: 9/17/2002 1:21:06 PM PST]

[Photos:]
photoMZ1808 Rod

Documented History (by the NGS)

01/01/1860 by CGS (MONUMENTED)
01/01/1901 by CGS (SEE DESCRIPTION)
DESCRIBED BY COAST AND GEODETIC SURVEY 1901 STATION IS ON THE MOUNTAIN OF THAT NAME, NEAR THE CENTER OF THE SUMMIT RIDGE AND ABOUT 2-3/4 MILES NNW OF HOLYOKE. THE STATION IS MARKED BY A COPPER BOLT SET IN ROCK SURROUNDED BY A TRIANGLE WITH THE LETTERS U.S. NEAR BY. FOUR REFERENCE MARKS, DRILL HOLES IN ROCK, WITH SQUARES AROUND THEM WITH ARROWS POINTING TOWARD THE STATION, ARE LOCATED, RESPECTFULLY, 19.21 METERS (63.02 FEET) SW. 6.53 METERS (21.42 FEET) NNW. 6.90 METERS (22.64 FEET) ENE. AND 6.15 METERS (20.18 FEET) SE OF THE STATION.
01/01/1930 by CGS (SEE DESCRIPTION)
RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1930 (RLP) STATION IS ON THE MOUNTAIN OF THAT NAME, NEAR THE CENTER OF THE SUMMIT RIDGE, AND ABOUT 3 MILES NNW OF HOLYOKE. THE MARK IS UNDER AND NEAR THE W CORNER OF A LARGE 2-STORIED OBSERVATION HOUSE OWNED BY THE HOLYOKE STREET RAILWAY COMPANY. THE MARK IS LOCATED 1.60 METERS BACK FROM THE FRONT OF THE BUILDING, AND 4.97 METERS IN FROM THE LEFT-HAND SIDE OF THE BUILDING, MEASUREMENTS BEING TAKEN FROM THE OUTER FACE OF THE WALLS. IT IS ALSO 3.21 METERS N OF AN OLD ANCHOR IRON SET IN THE ROCK, AND WHICH ONCE SERVED AS AN ANCHOR FOR THE MAST GUY. THE MARK IS 1.11 METERS FROM THE E CORNER OF THE SECOND PIER OF THE BUILDING FROM THE LEFT SIDE IN THE FRONT ROW OF PIERS, AND 2.54 METERS FROM THE W CORNER OF THE CORRESPONDING PIER IN THE SECOND ROW. AT THE MARK, THERE IS ABOUT 14 INCHES OF CLEARANCE BETWEEN THE SOLID ROCK AND THE FLOOR OF THE BUILDING. THE STATION IS MARKED BY A COPPER BOLT LEADED INTO THE SOLID ROCK AND IS CIRCUMSCRIBED BY A LARGE TRIANGLE ABOUT 12 INCHES ON A SIDE. THE SW REFERENCE ONLY WAS RECOVERED. ON ACCOUNT OF THE BUILDINGS, THIS DISTANCE COULD NOT BE CHECKED. THERE IS NO ROAD TO THE TOP OF THE MOUNTAIN. HOWEVER, THE HOLYOKE STREET RAILWAY OPERATES CABLE CARS TO THE TOP OF THE MOUNTAIN, AND WILL TRANSPORT EQUIPMENT FOR A VERY REASONABLE CHARGE. THERE IS A GOOD CAMP SITE ON THE TOP ON THE NW SIDE OF THE MOUNTAIN. CAMP SHOULD NOT BE MADE ON THE SE SIDE AS IT IS PART OF THE CATCHMENT BASIN FOR THE HOLYOKE WATER SUPPLY.
01/01/1934 by MAGS (SEE DESCRIPTION)
RECOVERY NOTE BY MASSACHUSETTS GEODETIC SURVEY 1934 THE STATION AND THE FOUR REFERENCE MARKS WERE FOUND IN EXCELLENT CONDITION AS DESCRIBED WITH THE FOLLOWING ADDITIONS--(1) IN 1929 THE OLD SUMMIT HOUSE BURNED DOWN AND A NEW OR TEMPORARY BUILDING WAS ERECTED. THE STATION AND REFERENCE MARKS NOS.3 AND 4 ARE NOW LOCATED UNDER THIS BUILDING AND WERE RECOVERED BY CRAWLING UNDER IT WITH A FLASHLIGHT. THE STATION IS ABOUT 18 FEET NE OF THE WESTERNMOST CORNER OF THE BUILDING. (2) REFERENCE MARK NO.1 IS IN THE OPEN BUT REFERENCE MARK NO.2 IS ABOUT 6 INCHES BELOW THE GROUND SURFACE.
01/01/1937 by MAGS (SEE DESCRIPTION)
RECOVERY NOTE BY MASSACHUSETTS GEODETIC SURVEY 1937 THE STATION AND THE FOUR REFERENCE MARKS WERE FOUND IN EXCELLENT CONDITION AS DESCRIBED EXCEPT THAT STATION IS IN HAMPDEN COUNTY, NOT HAMPSHIRE. STATION MOUNT TOM ECCENTRIC ESTABLISHED BY THE MASSACHUSETTS GEODETIC SURVEY, IS MARKED BY A STATE SURVEY STANDARD DISK SET IN LEDGE 80.5 FEET NE OF THE N CORNER OF THE SUMMIT HOUSE, 15.5 FEET SE OF IRON RAILING ON E SIDE OF APPROACH WALK, AND 124.4 FEET NE OF STATION MOUNT TOM, WHICH IS MARKED BY A COPPER BOLT WITHIN A TRIANGLE. MOUNT TOM REFERENCE MARK NO.5, 1860-1937, IS MARKED BY A STATE SURVEY STANDARD REFERENCE DISK, STAMPED MOUNT TOM ECCENTRIC, 1937, R.M.NO.5, 1862, SET IN LEDGE OUTCROP 49 FEET N OF NW CORNER OF SUMMIT HOUSE, AND 19 FEET E OF IRON RAILING ON E SIDE OF WALK. BECAUSE IT WAS IMPOSSIBLE TO OCCUPY THE MAIN STATION, IN 1937, THE MASSACHUSETTS GEODETIC SURVEY ESTABLISHED REFERENCE MARK NO. 5 AND USED IT AS AN ECCENTRIC FOR THEIR OBSERVATIONS ON THE CONNECTICUT RIVER TRIANGULATION. A 12-FOOT TOWER WAS USED. REFERENCE POINTS--FROM REFERENCE MARK NO.5 STATION MOUNT TOM, 1860, IS 92.015 FEET IN GEODETIC AZIMUTH 34 DEG 22 MIN 27 SEC. MOUNT TOM ECCENTRIC, 1936, IS 32.57 FEET, IN GEODETIC AZIMUTH 207 DEG 41 MIN 08 SEC. AZIMUTH MARK, THE CAMPANILE, AT THE CIVIC CENTER IN SPRINGFIELD, IS IN GEODETIC AZIMUTH 342 DEG 59 MIN 37 SEC. STATION NEW SALEM, IS IN GEODETIC AZIMUTH 219 DEG 00 MIN 27.79 SEC. TO REACH STATION, FOLLOW A ROAD CONNECTING HIGHWAY 10 IN EASTHAMPTON WITH HIGHWAY 5 IN HOLYOKE, FOR A DISTANCE OF 3 MILES SE FROM EASTHAMPTON, TO A SMALL ROAD STAND ON THE RIGHT, A SHORT DISTANCE BEYOND A GAS STATION AT A LEFT FORK. TURN LEFT AT ROAD STAND, AND FOLLOW A WOOD ROAD NORTHERLY FOR 0.5 MILE, AND CONTINUE ON A PATH UP STEEP SLOPE TO SUMMIT.
01/01/1938 by MAGS (SEE DESCRIPTION)
RECOVERY NOTE BY MASSACHUSETTS GEODETIC SURVEY 1938 THIS IS AN ECCENTRICALLY OCCUPIED FIRST-ORDER STATION MARKED BY A COPPER BOLT WITHIN A TRIANGLE, AND IS LOCATED UNDERNEATH THE SUMMIT HOUSE BUILT IN 1929 WHICH ALSO COVERS REFERENCE MARKS NOS. 3 AND 4. THE STATION IS ABOUT 18 FEET NE OF THE SW CORNER. REFERENCE MARK NO.1 IS IN THE OPEN AND REFERENCE MARK NO.2 IS 6 INCHES BELOW THE GROUND. REFERENCE MARK NO.1, A STATE SURVEY STANDARD REFERENCE MARK DISK SET IN ORIGINAL REFERENCE MARK NO.1 DRILL HOLE BY THE MASSACHUSETTS GEODETIC SURVEY IN JULY, 1938 IS LOCATED 63.02 FEET IN GEODETIC AZIMUTH 34 DEG 53 MIN 02 SEC FROM MOUNT TOM. THE OBSERVATIONS MADE FROM THIS POINT IN 1938 WERE REDUCED TO CENTER. REFERENCE MARK NO.5, MARKED BY A STATE SURVEY STANDARD REFERENCE MARK DISK STAMPED MOUNT TOM ECCENTRIC, 1937 R.M.NO.5, 1862 WAS SET IN LEDGE OUTCROP, 49 FEET N OF N CORNER OF SUMMIT HOUSE, 19 FEET E OF IRON RAILING ON E SIDE OF WALK AND 92.015 FEET IN GEODETIC AZIMUTH 214 DEG 22 MIN 27 SEC FROM STATION MOUNT TOM. REFERENCE MARK NO.5 WAS SET AND USED AS AN ECCENTRIC IN 1937 BY THE MASSACHUSETTS GEODETIC SURVEY. MOUNT TOM ECCENTRIC, 1936 ESTABLISHED BY THE MASSACHUSETTS GEODETIC SURVEY IS MARKED BY A STATE SURVEY STANDARD DISK SET IN LEDGE, 80.5 FEET NE OF THE N CORNER OF THE SUMMIT HOUSE, 15.5 FEET SE OF IRON RAILING ON E SIDE OF APPROACH WALK AND 124.4 FEET NE OF STATION MOUNT TOM, 1860. DISTANCE FROM MOUNT TOM ECCENTRIC, 1936 TO MOUNT TOM REFERENCE MARK NO.5, 1860 IS 32.57 FEET. AZIMUTH MARK, GRANBY, COMMUNITY PULPIT, SPIRE IS IN GEODETIC AZIMUTH 261 DEG 29 MIN 41 SEC.
01/01/1942 by MAGS (SEE DESCRIPTION)
RECOVERY NOTE BY MASSACHUSETTS GEODETIC SURVEY 1942 THE STATION IS MARKED BY A COPPER BOLT SET IN LEDGE, SURROUNDED BY AN 18-INCH CHISELED TRIANGLE. LOCATED IN THE NORTHWESTERLY PART OF HOLYOKE ON THE SUMMIT OF MT. TOM, 32.1 FEET SOUTHEASTERLY FROM THE IRON PIPE RAILING ALONG THE WALK AT THE WESTERLY EDGE OF THE SUMMIT. 52.1 FEET NORTHERLY FROM THE CENTER OF THE CONCRETE ROOF OF A SMALL STONE PUMP HOUSE, AND 126.1 FEET NORTHERLY FROM THE MOST EASTERLY CORNER OF THE STONE FOUNDATION OF THE DESTROYED HOTEL. THE STATION IS BEST REACHED AS FOLLOWS--FROM THE JUNCTION OF ROUTE 5 AND EASTHAMPTON ROAD IN HOLYOKE GO NORTHEASTERLY ON EASTHAMPTON ROAD TO THE CREST OF GRADE ABOUT 2.5 MILES. A WOODS ROAD LEADS NORTHERLY ALONG THE RIDGE FOR 0.5 MILE TO THE FOOT OF A STEEP RISE, UP WHICH A PATH LEADS ABOUT 400 YARDS TO THE SUMMIT. R.M. NO. 1, A U.S.C. AND G.S. REFERENCE DISK STAMPED MT. TOM, 1862, R.M. NO 1, SET IN THE ORIGINAL R.M. NO. 1 DRILL HOLE IN LEDGE. REFERENCE MARKS NO. 2, NO. 3 AND NO. 4 - A DRILL HOLE IN LEDGE SURROUNDED BY A CHISELED SQUARE WITH ARROW POINTING TO STATION. R.M. NO. 5 - A U.S.C. AND G.S. REFERENCE DISK STAMPED MT. TOM ECC., 1937, R.M. NO. 5, 1860, SET IN A LEDGE. 1936 ECCENTRIC - THE SHANK OF A DISK WITH A PRICK PUNCH IN THE CENTER. AZIMUTH MARK--GRANBY COMMUNITY PULPIT SPIRE. VIEW--A 12-FOOT INSTRUMENT STAND IS REQUIRED TO CLEAR TREES TO THE NORTH AND EAST AND FOUNDATION TO THE SOUTH OF THE STATION.
01/01/1959 by USAF (SEE DESCRIPTION)
RECOVERY NOTE BY US AIR FORCE 1959 THE STATION WAS RECOVERED IN GOOD CONDITION EXCEPT THE LETTERS U.S. WERE NOT FOUND. THE DRILL HOLES FOR REFERENCE MARKS NUMBER 1, 3 AND 4 WERE FOUND AND VERIFIED BY MEASUREMENT. THE STAMPED METAL DISKS WERE DESTROYED. ALL BUILDINGS DESCRIBED AS SUMMIT HOUSES AND THE CABLE CARS ARE DESTROYED AND TORN DOWN. TO REACH STATION, PROCEED NORTH ON HIGHWAY 5 FROM HOLYOKE, MASS., TO MT. TOM PARK AND RECREATION AREA. FROM MAIN BUILDING IN PARK FOLLOW DIRT AND GRAVEL ROAD TO BASE OF MOUNTAIN AND WEST SIDE OF WATER RESEVOIR. TO DRIVE TO TOP OF MOUNTAIN A FOUR WHEEL DRIVE VEHICLE WITH PLENTY OF GROUND CLEARANCE IS MANDATORY SINCE ROAD IS MADE OF BIG ROCKS AND BOULDERS. AT PRESENT, THERE IS A ONE STORY STONE BUILDING, TWO TV TOWERS AND AN AIRWAY BEACON ON TOP OF MOUNTAIN. THE STATION IS ABOUT 6 FEET SOUTH OF S-W CORNER OF BEACON LIGHT TOWER.
01/01/1960 by CGS (SEE DESCRIPTION)
RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1960 (SCM) STATION MOUNT TOM 1862 WAS RECOVERED AND IS IN GOOD CONDITION. THE OBSERVATION HOUSE MENTIONED IN PREVIOUS DESCRIPTIONS, IS NO LONGER AT THE STATION SITE. AN AIRWAY BEACON IS NOW AT THE SITE AND IS OBSTRUCTING LINE OF SITE TO MARKS MOUNT TOM ECC 1937 REFERENCE MARK NO 5 AND MOUNT TOM ECC 1936 FROM MOUNT TOM 1862. A TELEVISION MAST, WHYN WAS CONSTRUCTED ABOUT 300 FEET SOUTHWEST OF THE STATION BUT IT COULD NOT BE MEASURED TO. REFERENCE POINTS SW, SE AND NNW WERE RECOVERED AS DESCRIBED. A STANDARD REFERENCE MARK DISK WAS CEMENTED IN THE REFERENCE POINT NNW DRILL HOLE, STAMPED MOUNT TOM 1862 NNW. OBSERVATIONS WERE MADE TO STATIONS SHINGLE HILL 1885, SMITH COLLEGE 1937 AND MOUNT TOM 1862 FROM REFERENCE POINT NNW. A NEW DESCRIPTION OF HOW TO REACH THE STATION FOLLOWS. STATION IS REACHED FROM THE JUNCTION OF U.S. HIGHWAY 5 AND STATE HIGHWAYS 9 AND 10 IN NORTHHAMPTON. GO SOUTHERLY ON HIGHWAY 5 FOR 6.2 MILES TO A SIDE ROAD RIGHT WHICH LEADS INTO A PARK. TURN RIGHT AND GO SOUTHWEST FOR 0.1 MILE. TURN RIGHT AND GO WESTERLY, UPHILL FOR 0.3 MILE TO A PARKING AREA, PASS TO THE RIGHT SIDE OF THE PARKING AREA AND CONTINUE FOR 0.1 MILE TO A T-INTERSECTION. TURN RIGHT AND GO 0.1 MILE TO A T-INTERSECTION. TURN LEFT AND FOLLOW A MACADAM ROAD FOR 0.35 MILE TO A SIDE ROAD LEFT. TURN LEFT AND GO SOUTHWEST, UPHILL, ON A ROUGH AND ROCKY ROAD FOR 0.75 MILE TO THE SUMMIT OF THE HILL, AN AIRWAY BEACON AND STATION ON THE RIGHT. THE LAST 0.75 MILE WILL REQUIRE A POWER-WAGON VEHICLE. THE PROPERTY ON WHICH THE STATION IS ESTABLISHED IS OWNED BY THE U.S. GOVERNMENT.
01/01/1965 by CGS (SEE DESCRIPTION)
RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1965 (ETO) THE BOLT AND CHISLED TRIANGLE MARKING THE STATION WERE RECOVERED AND BOTH SEEM TO HAVE WEATHERED SOMEWHAT. SEVERAL DRILL HOLES, MUTILATED DISKS, SEVERED SHANKS, AND STANDARD DISKS WERE RECOVERED, BUT DUE TO THE CONFUSING NATURE OF THE OLD DESCRIPTIONS, NO ATTEMPTS AT IDENTIFYING REFERENCE MARKS WAS MADE. NEW MEASUREMENTS FOR LOCATING THE STATION ARE AS FOLLOWS-- 4.5 FT. SSE OF THE SW LEG OF THE MOUNT TOM AIRWAY BEACON. 6.1 FT. SW OF THE SE LEG OF THE MOUNT TOM AIRWAY BEACON. 26.1 FT. NW OF THE CENTER OF THE SW MOST FOOTING OF THE OLD SUMMIT BUILDING. 26.0 FT. W OF THE THIRD CONCRETE FOOTING NORTH OF THE SW MOST FOOTING.
01/01/1970 by MAGS (GOOD)
RECOVERY NOTE BY MASSACHUSETTS GEODETIC SURVEY 1970 (RAK) THE STATION WAS RECOVERED AT THIS DATE. THE DESCRIPTION AND TIES ARE SUFFICIENT. DESCRIBED BY R.A.KELLER, MAGS.

Control Text

  • 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.

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