Calculation of True Line / Original Surveys

Not sure what you are asking, but the math looks OK to me at first glance.

It says he ran due east (random) and landed about 3 feet north of the section corner, leaving a true return bearing of N89-58W along the north line of section 20.

See 'Table 3' in the “Standard Field Tables.”

I'm not sure when the first edition of this supplement to the 'Manual” was produced, but I have the 3rd Edition (GLO 1923), and 8th Edition (BLM 1956).

Some Manuals contain a table for this as well:

1902 Table XI, pg.118
1894 Table VIIa, pg.128
1881 first table, pg.58

My point being...
I don't think that anybody actually "calculated" it in the field.

Loyal

The random line was run for both distance and direction to establish the correct position of the quarter corner. The temporary quarter corner was placed to give a point to measure from. Upon reaching the previsouly established section corner, the overall distance of 80.04 chains is cut in half as is the falling distance of 5 links. The temp quarter corner is then moved 0.02 chains east and 2.5 links south where a permanent monument is placed. Albeit, there is going to be some discussion if the quarter corner was placed on a curve.

Loyal

I would think that a lot of those 1/4 cors. were set right away after they ran the random line and they could easily calculate the half distance of the falling and half the total measured distance and make the move off the temp. 1/4 cor.

In my time, of course we calculated all that back at our temporary office and went back days later to set the iron posts.

Oh, I almost forgot.....those lines were always on a curved line, either from the solar transit or from bending the lines on a transit line.

Probably right about the curve, but when the sun was not available, I think they used a North Seeking Gyro with approved tables and offsets for that one mile of curve.:-P
jud

Jud,

I really doubt that the GLO guys ever heard of a North Seeking Gyro??;-)

Curve, schmurve! Ain't no such thing on interior lines. What Jerry stated is probably the absolute best effort ever made. Generally, they didn't even move the temporary one unless it was way off. I'll bet you a dollar to a donut hole that was far more common than retracing steps and making fancy adjustments in the middle of nowhere. Time was money. Move on boys. Nothing to see here.

1 minute of deflection in 100'=.03', in 1000'=.3', in 1 mile 1.5'+

They fall 3.3' north on an east line.

So they calc. 2 minutes for the deflection angle or N89d58'W for line between the two section corners.

They probably work it out in their head without help from tables. The line is already run so they don't need to run it back, just walk to the temp point and move it.

Right Mighty Moe,

Didn't have radios, so walked (rode a horse) to the temp and moved it.

And of course it is possible that they did not move the temporary 1/4 cor., since it was close enough!

I just know the procedures that we had in my chaining days and that they probably were the same in the GLO days and in fact were curved lines.

Our error usually was more than the adjustment to the curved line, but the bending of transit line took care of the curve.

Yeah; 2.5 lks. That wouldn't be much of a move.

And 2 lks east. Hardly worth bothering with.

The bigger question with many of the surveys around here was did they make the connection to the section corner after they got 40 chains east. I think not; but without a time machine...;-)

During the time I worked for the BLM (1958 to 1994)all latitudinal lines were on the curve. The interior 1/4 corners and even 1/16th and 1/256th corners were calculated and set so as to be on the curve. Now, the question can legitimately be asked if the methods and procedures in use at the time justified the effort that was made, but I do know that the effort was made to place each and every latitudinal line on the correct curve for its latitude.

In the desert we could many times see from section corner to section corner and in those instances I know that the 1/4 corners were set on the curve NOT on a direct line of sight between section corners because I could see it looking through the transit. On township lines we could sometimes see for several miles and see the curve from the evidence of the flagged corner monuments.

The methodology of my surveying days was to set the corners of latitudinal lines on the curve. The accuracy of the work to accomplish that may not always be verified by today's GPS measurements.

Jerry

Jerry! I was just thinking of contacting you to see if you could enlighten some of these non-believers. Thanks very much for the post - hope all is well with you.

Jim

That of course is always the question?

Jerry Knight and I used identical procedures while running latitudinal lines and were meant to be on the curve.

It is a fact whether some want to believe it or not.

Keith

rishound,

You need to realize that not many of us, if any, have run original lines of the PLSS!

I have not and I doubt that any poster on here has. As a BLM land surveyor, we ran retracement/resurvey lines and with similar procedures as original surveys. We were not setting corner monuments as we ran the line, like the original guys did, but ran retracement surveys and back at the office, calculated the position of the new 1/16 corners, or where some lost corners should be.

A return to the field made the moves from the random lines to the true lines and naturally a newer look for any lost corner monuments.

We maybe ran east-west lines all across the township and noted the fallings at each corner monument and calculated all necessary moves from the random temporary points to the true line.

Keith

Does anyone know what they used to mark the temporary 1/4 corner. It's a bit of work to set a stone and place a mound. I'd think you wouldn't go to all that trouble if you might need to return and move it. I'd think they would set a stake and flag or something similar. Then return and offset from it and set the stone, mound, pits, whatever.

I've seen notes where I believe they actually chained it both ways because the topo calls are from the return line (I suppose you could hack it). I've also seen the topo calls on the random line. Then I've also seen some calls that made no sense at all. Then there is a herringbone where they just measured out 40 chains and set a corner (not in the notes) but the evidence on the ground indicates that.

The more PLSS work I've retraced has made me believe most of the deputy's were quite diligent and tried to do it right.

I can't believe that the temporary monument was set with a stone, unless they planned on not coming back and correcting it to the true line.

Our practice was a lath hub with a different colored flagging on it then the line lath flagging.

And realize too that the final field notes were not necessarily as it was run in the field. The random line had the measurement distances to everything and the final field notes were written in the Manual format.

Hey Keith,
Those of us who have worked for BLM in Utah, Nevada and Arizona have executed the original surveys of lots townships. Alaska, of course, is almost all original work. There is much original work left to do.

My work in Montana involved all dependent resurveys and the way you describe it is the way it was done. If a 1/4 corner on a latitudinal line was lost it was reestablished between the section corners just a little to the south (depending on the latitude) of a direct line of sight.

Jerry

Jerry,

Not many of those original surveyors posting here.

Obviously, I was not talking about Alaska BLM land surveyors.

Good to see you posting my friend and hope all is well with you and your family.

Everything is great in California.

Hello,

Thank you all for your insight. It is very interesting to listen to your experiences.
I appreciate your help.

Thank you, rlshound