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The EasternOblique Arc meets the Borden Survey

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You may recall my interest in the Eastern Oblique Arc (EOA), that grand undertaking of the Coast Survey (predecessor of the Coast and Geodetic urvey) which took much of the 19th century and resulted in the complete survey of the East coast from Maine to Louisiana as well as the first accurate determination of the shape of the earth and led to the North American Datum of 1900, father of our modern datum's. (See Holoscene's excellent site on this subject Benchmark Hunting Wiki - Eastern Oblique Arc )


On a vacation last year I found a number of monuments for the first section in downeast Maine (see My vacation intersects the Eastern Oblique Arc posted 10/1/2007)).


Then last April I spent some time exploring the section of the Arc in Massachusetts (see The Eastern Oblique Arc crosses Massachusetts posted 4/25/2008).


When I researched the stations in the Massachusetts which were part of the EOA, I decided to also search for the other stations which were the primary (First Order) stations for the survey of that state, For this, the CGS Special Publication No. 76 "Triangulation in Massachusetts" was invaluable. These First order stations consisted of the 10 EOA stations in the state, the 2 nearby EOA stations in NH, plus 7 other non-EOA stations which provided coverage in the western part of the state and on Cape Cod and the Islands, for a total of 19 stations. Here's a map from the Special Publication No. 76




Of these 19, with some great help from ddnutzy, I visited 9 of which only Blue Hill was not found (it was under a structure). And it was then that I discovered Simeon Borden and his survey. Borden was an inventor, engineer and self-taught mathmetician from Fall River and was named assistant to the head of the Trigonometical Survey of Massachusetts mandated by the state legislature in 1830. By 1834, the director had resigned and Borden took over. The work was finished in 1838 and presented to the American Philosophiocal Society in Philadelphia in 1841. This was the first state wide survey done in the US and was the first significant project done by anyone outside of the Coast Survey.


Meanwhile, the Coast Survey worked down the coast and did their work in Massachusetts between about 1845 and 1860, primarily under the direction of A. D. Bache who was then the head of the Coast Survey. The CS reused some of the Borden stations in their work (Wachusett, Manomet, Copecut, Great Meadow, Perry Peak and Indian) and for others, they used marks near Borden's stations (Monadnock, Greylock, Blue Hill and Beaconpole). The rest of the Borden Survey stations were adjusted to the CS stations and many of them are in the NGS database to this day.


Here is the Triangulation map of the Borden Survey, part of Borden's presentation in 1841. (This image is hard to read - click on the image for a large version. A very large version.). You will see many of the same stations, plus numerous others across the state.




This note is followed by 4 more notes: One note for the Borden stations found in June and July and the other for the several EOA stations in New Hampshire and Maine which we found. I was pleased to have the help of royswkr on some of these searches. I would also point out that most of the Borden stations have been recovered by others on GC. There's a small but expert group of Benchnmarkers working in Masschusetts.


These old marks were usually a copper bolt set in a rock, but sometimes just a hole. Finding the original bolt or hole is the ultimate, but sometimes the old mark was replaced (generally in the 1930s) by a disk. These RESET stations still mark the original location, but obviously a 1936 disk is not as cool as an 1833 copper bolt.


I managed to find 6 of the original Borden Bolts/holes (plus 2 bolts and 3 resets found in April) and 3 original EOA bolts/holes (Monadnock, Gunstock and Pleasant) plus one RESETs (Agamenticus) and a few DNFs of stations in both surveys (Unkonoonuc, Powow and Watatick).


Incidentally, when Hassler died in 1843, Bache succeeded him as director. Historical accounts mention that Borden was also considered for the post, but Bache, a professor (and great-grandson of Benjamin Franklin), was selected. Borden went on to do a variety of activities. There is a short account of Borden's life on Wikipedia.

Edited by Papa-Bear-NYC
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The 6 Borden stations found in June and July:


Holt (1833 bolt)

Salisbury Marsh Monument (1834 bolt)

Railcut (1834 bolt)

Prospect Waltham (1833 bolt)

Watatick Boundary Monument (1834 bolt - non-NGS)

Monadnock Borden station (1833 hole - non-NGS)


Borden stations recovered in April:


Pine Hill Reset (1835, reset with disk in 1932)

Manomet (1835 bolt)

Copecut Reset (1837, Reset with disk in 1934)

Wachuset 2 Reset (1833 bolt, moved in 1895. moved in 1936, original bolt still in use)

Mt Tom (1835 bolt)


The station title links to the GC logs. The Google Map link brings a up a map where you can show the RMs by using the "Show RMs" button. Click on a photo to show a larger version.


MY2568 HOLT - 1833 Copper bolt


A pleasant 10 minute walk to the top of the hill in a small park (Ward Reservation) run by the Trustees of Reservations. The station is a copper bolt in a triangle on a small rock outcrop in the grass about midway between the "Solstice Stones" (a local feature) and the fire tower. 3 RMs (disks) are also in the area.

Station MY2568 - Holt - Interactive Google Map


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MY5214 SALISBURY MARSH MONUMENT - 1834 copper bolt


This one is just off the causway to the beack on a rock outcrop. You will see a large stone monument with a hole in the center which exposes the original 1834 copper bolt. The station is now a Federal Base Network Control Station, accurate to about 1/2 cm. This 1834 bolt has come a long way!

Station MY5214 - Salisbury Marsh Monument - Interactive Google Map


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MY4950 RAILCUT - 1834 copper bolt


This is behind a parking lot in an indutrial park just off Route 128 in Gloucester. Click on the Google Map link and tell me that the continued existance of this mark is not a miracle!. Better go there quickly if you want to find it - it may not be there tomorrow!

Station MY4950 - Railcut - Interactive Google Map


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MY3638 PROSPECT WALTHAM - 1833 copper bolt


In a city park less than a mile from one of the busiest highways in the world, this is another marvel of existance in the face of development. About a 30 minute walk up a steep path from the parking lot. The mark is just past a very odd looking tower. This was the 4th First Order (or better) 1830s copper bolt of the day. That must be some kind of record!

Station MY3638 - Prospect Waltham - Interactive Google Map


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More Borden stations on next note.

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Watatick NH/MA Boundary Monument - 1834 copper bolt


This marker is not in the NGS database so the above link points to station "WATATICK 2 RESET", which is a short walk away.


Besides triangulation stations, Borden set a number of state line boundary monuments. Some of these preceded the formal agreement between the two states and the line was resurveyed in 1886 leaving some of these monuments on one side or the other. This one appears to be about 6 feet inside of New Hampshire. They were tied into the triagulation scheme as Third Order stations.


bd8ee6ea-bea7-4cd9-a597-a28dfc3c6de0.jpg d9035c52-a24f-44b9-97a1-4b72d71406d7.jpg


Monadnock Borden Station - 1834 drill hole


This marker is not in the NGS database so the above link points to station "MONADNOCK", which is about 30 feet away.


This mark is the oldest mark on the summit and pre-dates the CGS station and reference drill holes by about 25 years. It has a distinct shape with a rounded bottom, unlike any of the other drill holes on the summit. Borden also did not include it in his 1841 map, probably to keep that map for stations in Massachusetts only.


The CGS marker is also fairly unique as is the plethora of reference holes and disks on the summit, so I suggest you read through the GC log at the above link.




The Borden stations recovered in April are described in this thread mentioned above.

Edited by Papa-Bear-NYC
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EOA stations searched for June and July


Unkonoonuc 1848 (1848, DNF may be lost)

Gunstock (1860 Copper bolt)

Monadnock (1860 Drill hole)

Agamenticus Reset (1847, Reset with disk 1933)

Mt Pleasant Old and New (1847?, 1851? Copper bolts)


For those EOA stations visited in April, see the earlier thread mentioned above.


MY3800 UNKONOONUC 1848 - Drill Hole


This station was not found. A considerable amount of measurering and digging was done from the nearby UNKONOONUC 2 (MY3799) without success. The mark has been found only once since 1886 (in 1933) in spite of searches in 1959, 1963 and 1995, and the one accurate tie (a 1925 USGS disk) is now under a building, so this statiion may be lost. Photo shows the building and the hole we dug.

Station MY3800 - Unkonoonuc 1848 - Interactive Google Map




OC1335 GUNSTOCK - 1860 Copper Bolt


This station is at the summit of Belknap Mountain (in spite of the station name) and is often overlooked on this very popular peak. The bolt within the triangle does not stand out and one of the several nearby reference disks is often mistaken for the station.

Station OC1335 - Gunstock - Interactive Google Mark




MZ1474 MONADNOCK - 1860 Drill Hole


Monadnock is supposed the by the most often climbed mountain in the world (or maybe the second most often) and the statiion mark is often recovered. The unique station - a drill hole in a triangle with 5 lines radiating out and 2 other holes, one on either side of the station - make this a one-of-a-kind. To make my recover special, I searched for and found all 10 of the reference points mentioned in the NGS logs, including the 1833 Borden station. This is one GC log you really should read.


The map presents a difficulty for this station - there are so many RMs and they are so close together you can't make them out. I added a special map type "Blank" to help. Switch to "Blank" using the map type selector in the upper right, then click on the "Show RMs" button and zoom in as far as you need. I used the resulting scale diagram to find and keep track of all the marks.

Station MZ1473 - Monadnock - Interactive Google Map




OC2305 AGAMENTICUS RESET - 1847 Copper Bolt replaced by a Disk in 1933


We had read some the recent logs and studied the aerial photos and our main concern was that the station was under a viewing platform recently built over the foundation of the old WWII radar tower. We needn't have worried - when we measured how far the old concrete was from the side of the platform, we knew the station was at least 6 feet away from the platform. Then we noticed a large cracked field stone about 2 x 2 feet in size and about 4 inches thick just at the right spot. 20 minutes later, we had the stone off the spot and the debris underneath cleared and there was our disk pretty as can be at the bottom of a PVC pipe extending to about a foot underground. Some one saved us a h*ll of a lot of digging. We didn't look for the RMs.

Station OC2305 - Agamenticus reset - Interactive Google Map


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PF1145 MT PLEASANT OLD - 1847?? Copper Bolt

PF1147 MT PLEASANT NEW - 1851?? Copper Bolt


This was a real curiosity. The original copper bolt was set in about 1847 (the NGS log says 1853) But almost immediately someone built a hotel blocking the view from the station so another station was set about 50 feet away. For about 100 years there was confusion as to which was the "real" station. By 1958 the hotel was long gone and the NGS just made two stations, the OLD and the NEW (even though by our standards both are about equally old). It is probable that when the EOA was surveyed, sometimes one and sometimes the other were used for observations. Probably they should have stuck with one station (the OLD) and called the other point an eccentric. Whatever! Read the NGS datasheets for these two and try to stay un-confused!


We found the OLD station quite readily, but the NEW one took some digging. We finally found a drill hole (all the old reports said the bolt was falling out) but for something like this, one can never be 100% sure.. Read the logs. I may come back again sometime to dig some more if I have the time, just "to be sure".


When you click on "Show RMs" you can see where the old and new stations are but you lose part of the aerial imagery. Sorry.

Station PF1147 - Mt Pleasant Old - Interactive Google Map






Well that was it for this go round. But 3 our of 4 stations connecting the Massachusetts section to the Maine section is not too bad. Next project - finish up Maine.

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The unique and very old are the ones to make you do the "I/we found it" yell. And if you didn't you should have! You had so much fun both in finding and then compiling these, it should be against some law. :ph34r:


How many are there in Maine? We look forward to seeing your next adventures.



Maine of course has the international boundary with hundreds of cast iron monuments set in 1845. In a sense these "don't count", although they're all in the NGS database (besides they were all reset in concrete bases around 1910-1920). I've logged many of those over the last several years.


But my main focus this season will be the EOA triangulation stations. Holocene's EOA Wiki shows them. I've visited the ones in the very last section (see this thread), and just now a couple near the New Hampshire border, which leaves maybe a dozen in between. Of course these are just the primary stations. There are many, many secondary stations from the same era, but my philosophy is to select the special ones to go after. Otherwise you can get bogged down in one county for eons.

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