Section subdivision
Just curious, how many of you are subdividing sections and using the “line of constant bearing” (arc) on the east-west center of section line? If you are doing this, what’s your preferred method for calculating the intersection with the North-South center of section line? Also if you’re setting a 1/16th on a North or South Township boundary are you setting this on the arc as well?
TIA,
Doug
- 6 Replies
A good reference on how the G.L.O. did their section subdivisions (to set the C ¼ corner) can be found in the field notes that Deral of Lawton posted a few years back on the pipe vs stone thread on the old RPLS site before it was all messed up. Perhaps Deral can post these G.L.O. notes again.
Started doing this, but we had BLM & Forest Service Contracts. Of course most of the time there is an existing monument that’s used. Yes, also to the 1/16 corners. Often do comps using the seconds portions of Lat & Long. At a center section within 1/2 mile of Canadian border I believe it made about 2 tenths of a foot difference. Not enough to worry about in the field, but corners shown on the curve on the plat.
Evelyn
de minimus lex non curat…unless you are working under a federal contract or under state reg’s that adopt the manual, why do the mathematical masturbation…I set it at the intersect of straight line and hope and pray the next surveyor does not accept it to exhibit his ignorance! At the lat’s around here it’s between 0.14′-0.15′, with a 3 1/4″ diam. brass cap it hits pretty dang close to the north edge of the brass cap…let the pincushioner try to set something there!! If your working with good geodetic values and software, you can use a parallel of latitude as a check.
Pablo
You need to look to the instruments and procedures required in the original instructions/manual in effect when the township was originally surveyed by the GLO.
Here in Ohio, in the First Meridian Survey, and west in the Second Meridian Survey, the instrument was a Rittenhouse Compass and it would logically follow an arc in an East-West line.
Today, I don’t have that compass (wish I did) but I have RTK GPS. If I have an East and West quarter post I just get the lat and long on them and compute the mean and go to it, look for a center, and set one if required. It will be on the latitudinal arc.
The GLO set no centers or 16ths in the First or Second Meridian Surveys (Instructions of 1815; no manual).
Only on the “arc” if a township line, otherwise instructions say to put on the intersection of the 2 lines, N-S & E-W.
(Around here anyway)
Can you tell 0.2′ misalignment with a compass?
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