In retracing the original survey of the Connecticut Western Reserve, I have to rely on notes from a later survey 1808 which was in and of itself a retracement of the 1797 survey.
Special care was taken(in 1808), to relocate monuments placed in 1797 along with distances measured to these monuments in 1808.
The 1808 survey/resurvey was an establishment of a government to the south and mile markers were set accordingly as determined by those measurements. Found monuments of the 1797 survey were left as the pre-determined mile markers for the previous survey.
The 1808 notes include notations about nobs(hills), swamps and streams over 3 or 4 links width.
Therefore, I'm left with a lot of points to re-establish the described locations.
There are also notations about encampments. Sometimes the encampments lasted days.
But the notes don't indicate anything about moving the instruments.
For all I know, an instrument wasn't moved until the next encampment. Even if the hills and valleys made a line of site impossible to utilize.
I know that if a notation of Polaris is made, then the instrument must've been at that particular point.
I also know that if there's a new encampment, the instrument wasn't left "somewhere", on the traverse line. So the instrument was no doubt with the surveyors in the encampment.
Beyond these two instances, I have no idea when an instrument may have been moved forward.
In short, I have no idea of "how" . . . really . . . a long 120 miles traverse might have effectively proceeded.
I wonder if anyone on this site might know of some very, very concise notes of another long-line/baseline survey in this time period that might give me a little more operational insight and which might help me determine where an instrument might have been actually set up along the traverse?
this was an easy and enjoyable read.
there are other sources on how the mason-dixon line was run.
Mason and Dixon "survey report"
As Robert said, Mason and Dixon published an excellent article in The Philosophical Transactions of the Royal Society.
Has all the notes as well.
Found here;
Article 3 on the link...
Regards the M&D line, there are lots of sources, but one good one is a transcription of one set of Mason & Dixon Journals which tell in detail what they did.
Another situation which I have reviewed in the GLO records is running of many of the various PM baselines such as the 6th, etc. Also journals of a number of state lines defined by E-W bearing. The South Boundary of NY also, although I have not seen those notes. Another one is the Ellicot line that forms part of the N. line of Florida and parts of the south lines of Alabama, MS and LA.
It sounds like what you describe is only part of the process. If I were to use the M&D line as an example. The actual line is run with a transit like device capable of prolonging a line. After an initial direction is determined line is run forward on the ground by prolongation or by compass (a method initially described by Ellicott on the PA/NY line as a more economical way to run the line rather than the arduous prolongation method used by M&D) for a number of miles and then the astronmic guys would establish how far off the parallel of latitude they were and offsets would be computed back and true line cut out or blazed.
So the operations of line running, setting corners at mile or half mile intervals were often independent operations and may be in other notes. For a tangent line offsets to a parallel of latitude had to be combined with those for the misclosure in Northing based on observations. Where compass lines were used the lines run would be rhumb lines of a sort and that first offset not needed.
I think Ellicott claimed success for this on the NY/PA line, but soon after on the ellicott line in the south, the compass lines were run too far and drifted off more than a mile. The corrections by offset thus posed many problems for retracements because the monuments were not actually established by running the line, and any error in an offset would create a jog. This situation plagued the GLO for years in those southern states and does so to this day.
I reviewed some of the lines run for the Western Reserve virtually via google earth or earlier map and photo resources and found the lines to have been pretty good. The main reason is that I read about someone saying the work was defective or 'crap'. One of the key surveyors Seth Pease originally from Connecticut did a really good job particularly considering the tools and the other issues they had to face.
He also worked on lines in NY and then bacame one of the Surveyor's General in the South.
PLSS surveys were generally supposed to be run according to the true meridian, and by the time they were into Indiana and West under Mansfields vision it was initially by compass adjusted to occasional polaris observations. This procedure is documented in numerous instructions of the day not just PLSS but I have seen in instructions from Simeon DeWitt in NY in the late 1700's.
As we entered the mid 1800's they were controlled more by direct astronomic observations or actually by using the solar compass invented in 1835 or so by William Austin Burt.
The 6th PM baseline is interesting because instead of using elaborate astronomic methods the deputies who got the contract chose to run it with a solar compass. This seems to have drive the GLO guys in DC nuts. Many of the previous lines had been done with a lot of big astronomy involved. However the line run for 300 or so miles is very very good and is a real world lab for the validity of the solar compass.
Penry had seen NE notes on that and I have studied the GLO copy back east. Fascinating stuff.
Perhaps Seth Pease' notes are in some archive at the Connecticut Western Reserve and would be worthy of study.
Many other examples exist in state lines such as the line between Idaho and Utah which I think came west from the north line of CA.
A lot of lines run by Military guys like Major. Because he resorted to major astonomic regimes, many of his lines actually have pretty big errors (in my opinion).
The above link didn't work for me. I'll try one, although maybe they go out of date quickly?
Drawing the line
Regarding solar compass: In the 1852 Iowa-Minnesota boundary a solar compass ran a guide line, which was checked by another instrument and astronomical stations. This was one of the comparisons that helped prove the solar compass.
The book by Dodds on Original Instructions Governing Public Land Surveys of Iowa devotes a chapter to this line. I confess I have not studied it in full detail.
Perhaps Rich Leu will chime in, as he was involved in setting up a historical display at the initial point on that line for MN surveys.
thanks Bill for fixing the link.
dunno what happened.
I also have a book that was published by the state of PA around 1900 describing the line with fold out maps.
I may put it up for sale here soon if anyone that it is interested. It is a collectible, imo. a percentage of the sale would go to surveyconnect.
Actually that might've been me complaining.
I still can't get my tongue around long measurements and I don't adhere to surveyors who were attempting to do "accurate" work having added links.
Nonetheless it seems to be rather common for chains to measure long . . . which will always tax my thinking.
Maybe EVERYBODY always used stretched-out chains and added links to boot . . . I just don't know.
Don't Fault Ellicott
Ellicott used some of the same Mason Dixon equipment on the PA/NY line. He was not allowed to use it in Georgia by a PA group that while they did not know how to use were not going to allow others either. It was more or less locked up and then lost in a fire if I recollect my readings.
Ellicott surveyed the GA/FL line for the US since Florida was still Spanish territory. The State of Georgia then engaged him to survey the GA/NC line, but had no money for equipment, they essentially lent Ellicott a sextant. Then as now the quality of the survey follows the quality of the survey equipment. Then GA refused to pay him.
Paul in PA
Well your tongue (a very sensitive instrument) but it might be wrong... the basic premise when it comes to the chsin device or mearuring instrument is that every 'link' actually has a multiple of wearing surfaces in it. And so with only a few days let alone weeks of use the chain's mechanical surfaces would be wearing and it all adds up rather quickly to the length being long and the resultant measurement being repotted as short
A given chain 'device' is usually long and getting longer over the course of he survey subject to actual field procedures....
