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The Eastern Oblique Arc cross Massachusetts


Papa-Bear-NYC

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Last weekend, I spent half of Friday and almost all of Saturday and Sunday searching for ("chasing" might be a better word) triangulation stations in Massachusetts (plus one was in Rhode Island). Dave (ddnutzy) met me for most of Saturday and all of Sunday's fun. From my base in Natick Massachusetts, I drove 625.6 miles, and used 19.66 gallons of gas costing $65.70. This was all for 9 Triangulations (resulting in 8 FOUNDs and one NOT FOUND), plus 4 extra FOUNDs (one of which was a GREAT recovery - see below) and one locked gate.

 

So for my target group (9) that's 69.5 miles per triangulation station. Pretty sparse hunting, you might say. So I say, look at this map:

 

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These stations were part of the 19th century Triangulation of Massachusetts (which formed part of the Eastern Oblique Arc). This was published in 1922 as USCGS Special Publication No. 76. Use that link if you want to see the document (in PDF format). For more information on the Eastern Oblique Arc (EOA for short) see the 1902 USCGS Special Publication No. 7 or, for starters, read through Holograph's excellent article on the EOA on his benchmark Wiki site: Holograph's EOA article.

 

Here's a screen shot from my Google Map of the same stations plus those adjoining them up and down the coast:

 

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(Click on map to get the live interactive Google Map)

 

The blue markers are the ones which were part of the Eastern Oblique Arc, the two geen ones and the connecting line are the "Base Line", the red ones were other Massachusetts "Precise" stations (what we would call first order stations) not in the EOA, and finally the gray ones are the adjoining EOA stations to the north and south.

 

The ones I decides to go after were the ones in the east or mid state. These were (in order of our search):

Friday:

Thompson (1845)

 

Saturday:

Shootflying (1845)

Manomet (1835)

Copecut (1837, reset 1932)

Massachusetts North Base (1844)

Beaconpole (1844, reset 1932)

 

Sunday:

Blue Hill (1845, buired under a a concrete flag pole base sometime after 1991)

Wachusett (1833, moved 1895, reset 1936)

Mount Tom (1862)

 

Of the others (of course there are always others to persue) Nantucket Cliff was lost 100 years ago and Equinox and Graylock were destroyed when the summits were "defaced" with structures. Massachusetts South Base was evidently destroyed when new tracks were laid some time prior to 1934, and Great Meadow is in a National Guard facility which was closed and locked tight when we went there on Saturday.

 

Almost any history of geodetic surveying in Massachusetts starts with Simeon Borden (1798-1856) (see Wikipedia entry). He is credited with inventing the first accurate apparatus for measuring a base line and was instrumental in doing the Massachusetts Triangulation (commonly called the "Borden Survey") in the 1830s. Borden was doing his survey in Massachusetts around the time Hassler was working in the mid-Atlantic states. Many of the stations used by the US Coast Survey as part of the EOA used Borden's survey points. The Massachusetts Survey documented in SP No. 76 used most of the Borden survey as part of the USCGS triangulation. Of the 19 "Precise" stations shown on the map above, 6 were Borden stations. We found 2 of the original Borden stations, Manomet and Wachusett, although the Wachusett station has been moved twice (see below). One of our "extras" was also a Borden station, which were were very pleased to find.

 

The other name that occurs frequently is A.D. Bache, who was the head of the Coast Survey after Hassler and has his name on a great number of triangulation stations in the late 1840s to early 1860s up and down the East Coast. 6 of the 19 were Bache stations of which we found 4 (although Beaconpole was reset in 1932) Blue Hill (buried) is also a Bache station.

 

In the next note I will give short summaries of our recovery efforts, and then I'll mention our special "extra" finds.

Edited by Papa-Bear-NYC
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Friday

 

MY4858 - THOMPSON

Copper plug set in 1846 by A.D. Bache

 

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(Click for larger image)

 

This station is on Mount Ann in Mount Ann Park near Gloucester. The land is owned by the Trustees of Reservations and I talked the manager into hiking up there with me to see what the station was all about. Public access is currently restricted due to issues with neighboring land owners. It was about a 20 minute walk on a lovely Friday afternoon. The views from the open rocky peak were impressive. The station and all 5 reference marks were recovered.

 

Saturday

 

LW3984 - SHOOTFLYING

Copper plug set in 1845 by A.D. Bache

 

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(Click for larger image)

 

This station is actually in the center median of the mid-cape highway in Barnstable. Luckily there was little traffic at 7:00 AM Saturday and I could park on the left of the west bound lanes. There use do be a rest area there but there is no trace of it now. There was a faint grassy road leading to the station. I also found 2 of the 3 reference marks, but shanks only.

 

LW4436 - MANOMET

Copper plug set in 1835 by Simeon Borden

 

ddnutzy and Papa Bear on Manomet

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I met up with Dave (ddnutzy) for this station and we worked together the rest of the weekend. The summit of Manomet Hill is about a 10 minute walk from Route 3A. We found the station and and 3 reference marks (RM4 Reset, RM6 Reset and Manomet Magnetic). We didn't find RM1, and RM5 was destroyed when the boulder it was on was moved down to the town fire house (with a memorial plaque attached).

 

LW2119 - COPECUT

Copper plug set in 1837 by Simeon Borden, Reset with standard USCGS disk in 1932

 

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(Click for larger image)

 

The road up to Copecut Hill was a beast with large holes everywhere. Travel was slow. There is a fire tower on the top and there was a fire warden there who said hello. Rather than opening the gate, he (and we) just walked through the large hole in the fence. There was nothing on the datasheet about a reset, so we didn't know what to expect. What we found was the station disk and 1 RM disk in good condition. We did not find the other 2 RMs after a brief search. Given the out of the way location, this area gets very little traffic.

 

MY3577 - MASSACHUSETTS NORTH BASE

Copper plug set in 1844 by A.D. Bache

 

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(Click for larger image)

 

This station is behind a relatively new house on Summer Street in Foxboro. We were lucky that a woman drove up just as we arrived. She said to go ahead and search and that we were not the first to search for the "old tower" (which we knew had been demolished about 100 years ago).

 

We first found Reference "11MB" (near the RR tracks) - with the help of my GPS and metal detector - and measured off the distance to the station, but could not find it after much digging (we found many pieces of brick from the old tower). Then we "guessed" RM2 (which was not described in the datasheet but appears in the box score) was a 1/4 inch hole we found in a boulder to the north of the station. Taking a measurement from this drill hole led us to the station, which was in plain site!

 

LW2764 - BEACONPOLE RESET

Copper plug set in 1844 by A.D. Bache, reset with a standard disk in 1932, only the shank remains

 

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(Click for larger image)

 

The station mark is the shank plus a small portion of the center of the 1932 disk with the triangle and center dot preserved. Thus the geodetic point is preserved and this station is actually in "good" condition in spite of the damage. It almost looks like a copper bolt, but alas it is a disk shank.

 

The station and 4 reference marks (RM1, RM3 Reset, RM4 Reset and RM5) were recovered. We could not find RM2 (a drill hole). All disks have been removed with only shanks remaining.

 

And that was the end of our 13 hour Saturday adventure.

Edited by Papa-Bear-NYC
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Sunday

 

MY3472 - BLUE HILL

Copper plug set in 1845 by A.D. Bache, currently buried

 

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(Click for larger image)

 

This proved to be the one big disappointment of the weekend. We had read all the logs on this site and knew that several benchmarkers had said that the flag pole had been built over the copper plug, but we had to see for ourselves. We found 4 reference marks (3 drill holes: old RM2, old RM3 and old RM4 and the 1932 disk: RM1). RM2, another 1932 disk was not found and presumed to be underground inside the observatory fence. Careful measurements from each of these recovered reference marks indicated the station was directly under the flag pole.

 

Our only hope (a slim one) is that when they built the flagpole base, they placed a pipe from the top down to the ledge where the mark is (was?) so that by removing the flag pole, a surveyor could site on the 1845 marker. But as for now, the 1845 copper plug is lost (but not forgotten).

 

MY3792 - WACHUSETT 2 RESET

Copper plug set in 1833 by Simeon Borden, moved in 1895 due to construction, reset in 1936 after being damaged by a car

 

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(Click for larger image)

 

The original copper bolt set in in 1833 is still intact. However it was moved twice in its history, the first time (in 1895) by men building the summit hotel (long since burned down); it was put back and was renamed Wachusett 2, then the stone it was set in was hit and moved by an automobile in 1936 so it was reset and renamed Wachusett 2 Reset. But the copper bolt is the original Simeon Borden bolt of 1833.

 

The station and 5 reference marks (RM3, RM6, RM8, RM11 and Wachusett Magnetic) were recovered. One (RM10) was found moved about 40m from its correct position. Several others are lost or under the parking lot. A compass rose was also found, a rather attractive monument.

 

MZ1808 - MOUNT TOM

Copper plug set in 1862 by A.D. Bache

 

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(Click for larger image)

 

We managed to drive entirely around Mount Tom before finding the best way up. The directions given on the datasheet by (RPM) in 2004 are the best directions but we neglected to read them (till I got home). 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. That was a major find - see the next note.

 

And thus ended our weekend with 8 out of 9 stations recovered. Not bad at all.

 

Extra Credit

 

LW4668 - PINE HILL RESET

stone post set in 1835 by Simeon Borden, reset with standard disk in 1932

 

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(Click for larger image)

 

On Saturday, between Shootflying and Manomet, I met up with a group of County High Pointers for a visit to Camp Edwards, a National Guard base. Visits must be pre-arranged with the base.

 

This was not one of the primary stations but was a secondary station - a 4x4 inch brown stone monument set in1835 by Simeon Borden. This original marker was lost and was reset using an underground mark (a bottle buried 3 feet underground) in 1932 with the current disk.

 

A surveyor had set up a tripod with a GPS antenna over the mark. So soon we will move from an 1837 stone post to a 1930s disk to a 21st century high-tech station. What would Simeon Borden or A.D. Bache think about that!

 

MZ1807 - MOUNT TOM BORDEN

Copper plug set in 1835 by Simeon Borden

 

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(Click for larger image)

 

After recovering that station Mount Tom and most of the RMs, we set about finding this one. This mark is 18" underground and until recently a building was on top of it. But a few years ago, the nearby air beacon tower and the equipment building which was over the mark were removed, and so we had a chance.

 

We took the distances from reference points given in the 1896 and the 1934 recovery logs. After repeated measurements and digging for about an hour, we hit bedrock and found a depression in the bedrock. Dave cleared it out and said "I see a copper bolt with a cross on top"

 

We found it! We checked the measurements and it was right on from the two early descriptions. The photos were difficult to get since the bolt was way down in the hole and we continually knocked dirt and gravel down on top of it.

 

We believe we are the first to recover this since 1934, and therefore we are very likely to be the only two folks alive to have seen it.

 

A great way to end a great weekend.

Edited by Papa-Bear-NYC
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I've found quite a few benchmarks on Mountain tops around New England using the USGS paper description the box,highlighters.compass,100m tape and a metal detector plus the other tools in my bag.My only companions on these trips were Wildbird, probably 20 or so finds and Blackstone Val with 7 or so. All the rest were by myself.

 

Last weekend I had the privilege of spending two days looking for benchmarks with Papa Bear. The organization was amazing. All the stations and Rm's were laid out on Google Earth with the azimuths and distances in both feet and meters. He had all the USGS descriptions and the maps in the order that we were going to look for them. He also had Mapquest directions, or something like that from point to point so that it would be easy to get from one station to another.

 

All I can say is that it was a enjoyable weekend of benchmarking finding stations that were used in the surveying of Massachusetts in the 1800's. There's no way that I would ever have figured out how to do what Papa Bear did for that weekend.

 

Dave

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...

All I can say is that it was a enjoyable weekend of benchmarking finding stations that were used in the surveying of Massachusetts in the 1800's. There's no way that I would ever have figured out how to do what Papa Bear did for that weekend.

 

Dave

And for my part I can say I would never have gotten through all the work and travel without Dave. Especially digging that hole. We were a good team and I look forward to a repeat performance some time. And to be honest, sometimes I think I need to plan less and get out more.

 

Richard aka Papa Bear

Edited by Papa-Bear-NYC
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Wow, what an historic trek! I'll have to follow in your footsteps some time!

 

If you waited one more Saturday, you might have seen me at the Blue Hill Observatory Open House. Granted the weather wasn't as nice...

 

There is one note that I want to add about Blue Hill. The flag pole, though a benchmark, appears not to be the one that was the copper rod by Borden. The copper rod was set in the present day location of the Blue Hill Observatory tower, according to the text in MY3471, Blue Hill Borden. There is a triangular brass plate with text that approximately marks the location. Picture included:

 

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The plates states that the "x" "was the copper bolt set". The datasheet further explains that the copper rod was searched for when the tower was built but not found and that the exact location may never be known. Also, since the other setting is used as a reference, it is likely that the flag pole is not where the copper bolt was set.

 

But that doesn't detract from your careful work. My hat's off to you!

Edited by NorStar
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Wow, what an historic trek! I'll have to follow in your footsteps some time!

 

If you waited one more Saturday, you might have seen me at the Blue Hill Observatory Open House. Granted the weather wasn't as nice...

 

There is one note that I want to add about Blue Hill. The flag pole, though a benchmark, appears not to be the one that was the copper rod by Borden. The copper rod was set in the present day location of the Blue Hill Observatory tower, according to the text in MY3471, Blue Hill Borden. There is a triangular brass plate with text that approximately marks the location. Picture included:

 

The plates states that the "x" "was the copper bolt set". The datasheet further explains that the copper rod was searched for when the tower was built but not found and that the exact location may never be known. Also, since the other setting is used as a reference, it is likely that the flag pole is not where the copper bolt was set.

 

But that doesn't detract from your careful work. My hat's off to you!

I think you're confusing things here.

 

1) The flag pole is not a benchmark.

 

2) Borden set a copper bolt in 1834 (or 1832)) This is PID MY3471. This was lost when the tower was built in 1872. The tower was rebuilt in 1908 and the 1932 recovery states that the plaque on the floor is probably wrong as to the location and that the Borden station is not recoverable. It has not been seen since sometime prior to 1872.

 

3) A.D. Bache set another copper bolt in 1845 (or 1844) supposedly 26.25 ft. from the Borden station. This is PID MY3472 and was used by the Coast Survey in the Eastern Oblique Arc. This is the one I was looking for. This was fine as late as 1991, after which it was buried by the flagpole. A picture I included in my note shows the triangular fence built around the CGS mark in 1934:

 

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The second photo shows the flagpole was built directly over this fence:

 

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There is no confusion over where either station is. The CGS station (MY3472) is covered by the flagpole as we verified by careful measurements from 4 reference marks and verified by the photos of the old 1934 triangular concrete fence. The Borden station (MY3471) is probably destroyed (as of 1872) and was somewhere under the tower, but not likely under the plaque.

 

Now here's something you could do since you work there. Go out and lift up the plastic or sheet metal thing around the base of the flag pole. See if the flagpole is set directly into the concrete or if it is in some kind of shaft and therefore might be removable. My only hope is that they put some kind of shaft all the way down to the bedrock so when the flagpole is removed, a surveyor (or benchmark hunter) could take a position on the 1845 A.D. Bache copper bolt which (hopefully) is still under there.

 

For the 1832 Borden copper bolt, I have no hope.

Edited by Papa-Bear-NYC
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