but still has to do with curved section east-west centerlines!
Jerry Wahl posted below:
"Keith would say he could pull a mile of barbed wire to subdivide the section. I guess you might be able to do that with a few teams of horses.
- jlw"
and this:
by jlwahl, Friday, February 25, 2011, 21:55 (11 hours, 0 minutes ago) @ Keith
But the subdivision of section lines are defined by the act of 1805 to be straight. One of those little exceptions to the rule. Now Mr. Dahl has decided that is not true any longer, so we have the new manual applies to BLM but no one else. Really that is the truth, and it invokes a concept wherein past acts are forgiven. So any center quarter set by the BLM (darned few) at intersect of straight lines is still okay, but now what?
Get out that spool of barbed wire and pull it up...
By the way what does any of this have to do with presidents day?? as if you needed any validation of something?
- jlw"
Jerry, to prove your point, why don't you lead a discussion on how Eastern States accomplished the resurvey and survey of section lines and subdivision of section lines that were discussed in the Florida Appeals Court case of Rivers v Lozeau?
For instance, were those east-west subdivision of section lines on a constant bearing or did they have broken bearings, which would indicate that they were instrument straight lines?
I am surprised to learn and I would suppose that Bob Dahl is likewise, to learn that he alone decided to that from now on, section east-west subdivision lines are curved.
I was returning curved lines back when I was in the field in the 60's!
Wait, back in 1805, were the straight lines run with a compass?
Keith
I feel like a midget among giants but shouldn't the Statute be interpreted in light of the methods and procedures available in 1805?
If the customary method used resulted in a true line of latitude (notwithstanding errors present) then it seems like that would be the answer to the question of precisely what they meant.
Dave,
I think one could assume that the Statute was being implemented with the existing equipment that was being used.
Keith
I think we could agree that a compass line that is run on the ground, in a easterly direction, would be a curved line? I have not actually ran a compass line so can't say for sure, but I have ran many east-west lines with a solar transit and those lines are automatically on the curve.
Keith
Following the footsteps of the original surveyor is a precedent set by several court cases throughout the history of land surveying. Creating manuals, after the original survey was completed, is only speculation of how the land was actually originally surveyed. You need only to visit 'errata' at the web site BLM Survey Manual to see what a disaster the 2009 manual is.
A matter of perspective
Tell me the point of perspective and then I can tell you if the line is straight or curved. An east-west line which maintains constant latitude will appear as a circle on the ellipsoid if viewed from directly south of the south pole or directly north of the north pole. Viewed as if the pupil of the eye was coincident with the plane of latitude, the line would be straight. Viewed from any other perspective, it would be an ellipse.
A line run such that it does not maintain a constant latitude is not an east-west line. It however may, but not necessarily, if viewed from some specific point appear straight.
If discussion moves from the ellipsoid to the geoid, then it is yet another story. That is the result, and the beauty, of language. Until all the perspectives, conditions and assumptions have been stated and agreed upon, there will be senseless argument!
A matter of perspective
As a government PLSS surveyor I, as with Keith and Bob Dahl, always ran my east-west section centerlines on the latitudinal curve. If I wasn't using a solar attachment I adjusted the lines a was running that were moving easterly or westerly to compensate for the changes occuring to my longitudinal position. Every surveyor I ever worked under in BLM utilized these methods.
Skip
I would have to imagine that the way I was taught in the field to bend the bearings on my instrument straight line, when running east-west lines, was more than likely the method used by the GLO guys from who knows how long ago.
It certainly was no secret and of course in our days in the field, we didn't concern ourselves with the precise difference between the location of the center 1/4 cor., whether by instrument straight line intersection or our normal method. Come to think about it, I don't ever remember a circumstance where I could see from the east 1/4 sec. cor. to the west 1/4 sec. cor!
Anyways, for you guys who can measure the width of my finger nail, you should at least follow the proper procedure.
Keith
Skip
If you have your compass set over the W 1/4 corner and could see the E 1/4 corenr,
would you run the 1/4 section line as a curve?
Yes assuming the absence of errors and local attraction, a compass line run east will be curved. Obviously we know that running lines with compass is only capable of so much accuracy.
A matter of perspective
normally when I stand on the ground I am standing normal to the globe. If you draw a line through my head and between my feet it will intersect the center of the earth. This is why latitudinal lines appear to be curved from our perspective.
Skip
I think if you set your compass over the west quarter corner and sight the east quarter corner the bearing would be N 89°-something' E but you should set the center of section a little bit south of the straight line (something on the order of a 1 or 2 tenths of a foot in the Continental US).
That would be the result of most 19th Century surveyors work assuming in most cases they couldn't actually see across the entire section. Like I've said elsewhere most Private Surveyors in California over at least the last 30 years have neglected the difference and just put it on the straight line. But I get Keith's point that if we are getting down to splitting hairs then why not follow the absolutely correct procedure per the Manual and run all of our lines on a latitudinal line which isn't that difficult to do given the computer power and instrumentation we now possess.
Dave
You are absolutely correct and I do post this info about center 1/4 sec. cors. for the exact reason that you understand my point.
If some get tired of me posting this info, quit reading my posts.
Seems to be a simple concept to me!
Keith
O.K. Keith...In Wyoming we don't have to work with no stinking running of lines and can set straddlers by line of sight at the intersection of opposing 1/4 corners and set the corner by intersection. My question is, how far off is it from the curved line and the supposedly parallel of latitude? :>)
Pablo
Pablo
I am sure you can calculate that better than I can!
I am sure that you can measure better than I did!
And your point is?
Keith
Pablo
I'm just glad to find any previous surveys within 5 ft. and who cares if it's not down to a parallel of latitude nats arse or not. If the line has been run and set in the field I accept it.
Pablo
Pablo
Obviously, I would think that more surveyors would have your opinion, but you know better than I, that they don't.
Too much dependence on machines and not enough on procedure.
You have read the same comments and seen the pin cushion corner monuments on here and it only means that measurement precision is the judgement.
And of course if they can measure that close, they can follow legal procedures too.
Keith
Pablo
I am off to the theata' (is that the sophisticated pronunciation) and maybe one day, we can see an explanation of those BLM resurvey lines in Florida that I have referred to?
Huh, Jerry?
Keith
A matter of perspective
Consider Great Circle Routes - For any line on the surface of the earth, the shortest line connecting them is the one where you have a plane formed by the start point of the line on the surface, the end point of the line on the surface, and the center of the earth.
This is why, for example, the shortest possible flight from Washington DC (38°53?42.4?N 77°02?12.0?W) to Doha, Qatar (25°17?12?N 51°32?0?E) takes you up over Edinburgh, Scotland (55°56?58?N 3°9?37?W).
Can everybody agree that the E-W lines on the globe are curved?
Can everybody agree that running a line from E to W 1/4 Cor. or vice versa in the lower 48 states, it doesn't make a damn bit of difference if you take that into account or not?
Can everybody agree that if a line is run on a constant bearing from E to W or vice versa with a compass or solar transit with multiple sightings that barring the inevitable errors and fluctuations in local attraction, etc., the line will be a sequence of straight lines that approximate a curve and not really a curved line?