Maine U S G S Bench Mark "115.38"

[Papa-Bear-NYC]

When we finally made it to Orono last weekend, the weather had turned to rain so I was lucky to get two marks on the U. of Maine campus.

 

Here's a shot of PE0518 "115.38".

 

(click for larger image)

 

The interesting thing I notced when I found this mark was the scribbling on the bottom of the disk to either side of "B.M.". At first I thought it was some stuff students had put there, sort of like "Kilroy was here". But these stampings were much too fine and accurate. Then I saw that they were actually notated on the datasheet:

PE0518_MARKER: DD = SURVEY DISK

PE0518_SETTING: 36 = SET IN A MASSIVE STRUCTURE

PE0518_SP_SET: BUILDING

PE0518_STAMPING: 115.381 BANGOR JWE 89 EID 01

Here's some closeups:

 

Lower left "J.W.E. 89"

 

Lower right "E.I.D. 01."

 

So what are these? They sure look like someone's initials and dates, but the dates seem much too recent. And if they are recovery dates they don't correspond to any recovery logs on the datasheets. And as I said above, they seem much too fine and accurately done to be grafitti. But then, with engineering students, you never know.

 

Here's a list of other questions about this mark:

 

1) Monumentation date. Datasheet gives "UNK". Does any one know when the USGS stopped using marks with "B.M." on the disk? The ones from 1934 in Bar Harbor say "BENCH MARK".

 

2) Accuracy of elevation. 115.381! That's pretty fantastic. Any idea of what kind of accuracy you would expect for an early 20th century USGS bench mark? The NGS, perhaps with a bit of institutional skepticism, shortened the designation to "115.38"

 

3) Datum. It is stamped "BANGOR". I don't know what this might mean, but I have seen several USGS BMs that have a local town where it says Datum. perhaps these were primary bench marks that they used to level from in a particular area.

 

Neat mark. It's on one of the Engineering School buildings. I'd love to know more about it and when it was put there.

Edited June 7, 2006 by Papa-Bear-NYC

[DaveD]

This is a very old style USGS mark and was probably set in 1901. I can confirm that when I get back to the office on Monday. This mark would most likely have been tied to the primary leveling network established by C&GS and related to Mean Sea Level as determined at Sandy Hook, NJ. Commonly referenced as the Second General Adjustment.

[mloser]

I have found a few of these old USGS marks, all in churches I think, and all from the early 1900s. KW0577 is an example from 1900, but don't look at my small, dark pic. Look at someone else's recovery for a good image of it. LW0206 is near Middletown, NY and dates from 1903.

[Papa-Bear-NYC]

This is a very old style USGS mark and was probably set in 1901. I can confirm that when I get back to the office on Monday. This mark would most likely have been tied to the primary leveling network established by C&GS and related to Mean Sea Level as determined at Sandy Hook, NJ. Commonly referenced as the Second General Adjustment.

Hmmm ... So maybe the "01" doesn't mean 2001, but rather 1901! That would be cool. But the "89"? 1889? Unlikely, but I guess I could find out from the U. of Maine folks when the building was built.

[mloser]

Other threads here led me to believe that the earliest benchmark disks were set around 1900. Dave might have been part of those, or me might be able to shed some light now.

[+Ernmark]

..Dave might have been part of those, or me might be able to shed some light now.

 

You mean Dave actually set them in 1901? - wow !

 

- by looking at the wear in the disk, the stamping in question looks much more "current" than the rest of the disk

[Photobuff]

Other threads here led me to believe that the earliest benchmark disks were set around 1900. Dave might have been part of those, or me might be able to shed some light now.

 

I've seen disks around here from the late 1800s, and though I haven't dug it up, I'm pretty sure we have one still around from 1875. Don't know about Maine though. The 1875 mark was next on my list, but my wife broke her arm, and I've had way to much to do to get out benchmark hunting. The blasted thing is also buried three feet down, so I want to be darn sure of the location before I dig.

Edited June 8, 2006 by Photobuff

[+Black Dog Trackers]

Here is an old thread on old disks with a nice list from Holograph. I think the oldest disks are the Missouri River disks from around 1885 or something like that.

[CallawayMT]

PBNY,

 

The source for these USGS BM caps and tablets can be found in the USGS Bulletin: "Results of Spirit Leveling in Maine, New Hamshire and Vermont 1896 to 1909, Inclusive (USGS Bulletin 437)

Marshall, R. B., Chief Geographer".

 

These bulletins do not show specific dates, but do indicate when and where runs began and where they were run to. You will sometimes get more information on specific marks than you will find in the NGS description for the marks included in the NGS database.

 

I have about 10 different states, and use them when I travel to find these unique and historic monuments. You also get a little extra history and a lot of the caps which you can go find by description only.

 

You can buy this one at www.abe.com and search by description for "spirit leveling Maine". $10 plus a few bucks shipping or go to your local government publication library.

 

CallawayMT

[Papa-Bear-NYC]

I've done a little internet research and found two pieces of information pertaining to this mark.

 

1) The building: according to a story on the University's web site (about a bell that at one time hung on this building); Wingate Hall opened in 1894 and was "the former the home of the College of Technology, now the College of Engineering" (U. of Maine story).

 

2) Historic 1902 USGS map: this is the clincher. Here is a portion of the USGS 1902 Orono quad "Surveyed in 1900 in cooperation with the Sate of Maine." (1902 Orono quad, SW portion). It clearly shows this benchmark with an elevation of 115.

 

 

We'll see what DaveD comes up with when he gets back to the office, but if you ask me, that's pretty strong evidence that the mark was set sometime between 1900 - 1902, depending on how long the surveying took and how long after the survey the map was produced.

 

Now for what the initials mean - I'd be blown away if the original surveyor's initials were "E.I.D."!

Edited June 9, 2006 by Papa-Bear-NYC

[Papa-Bear-NYC]

Thanks to DaveD, who has access to the USGS datasheet for this mark I have some information:

 

The level line was run in 1900 from a station in Bangor. The Chief of Party was J.W. Edgerly.

 

This explains the stamping "DATUM: BANGOR". Dave indicated that the convention of using an accepted starting point as "DATUM" was the practice at that time. It also explains who "J.W.E." was - namely Mr. Edgerly.

 

The dates "89" and "01" are a bit harder. The building was built in 1894 so 1889 is problematic.

 

Here's a speculation:

 

The process had 3 stages: monumentation, leveling and stamping (after doing the least squares analysis and adjusting the level vaalues accordingly). So my speculative timetable was:

 

1899 - mark is monumented.

1900 - leveling is done

1901 - values are stamped on the disk.

 

So "J.W.E. 89" is a typo (don't laugh) it should have been "J.W.E. 99". The stamping of the DATUM and these initials may have been done back at HQ before the mark was set. "E.I.D. 01" is the who and when the final values were stamped onto the disk.

 

It's fun to speculate, but it's even better to get real information.

 

Thanks Dave.