One other mapping technique that isn't encountered all that often, but is quite useful is seen in the detail below. This is a way of showing an linear feature in a way that makes it easier to detect the underlying pattern that would defeat a simple linear regression or best fit routine. I believe that in his book "Boundaries and Landmarks - A Practical Manual", A.C. Mulford mentioned this technique for fitting a line to the irregular evidence of remnants of an old fence or other scattered evidence of a line surveyed
The diagram was compiled with two scales, one in the longitudinal direction, chosen to fit 14612.38 linear feet of line into a relatively compact strip, and another in the transverse direction, chosen to show the offsets of even three or four feet from a baseline fairly clearly.
A county road that was originally established in 1881 as a first-class road runs along the line from about 59+40.61 to 146+12.38. There was some question as to how the road was originally located, but from the double-scale plot it was obvious that the road was laid out as a 40 ft. wide right-of-way that simply changed sides of the land grant line around 108+47.29 and was later narrowed in places to about 30 ft. for some reason.
It seems to me that this would be a good way of illustrating in an inset detail or in a report the relationship of a line to irregular occupation or other evidence along the line.
Ever seen a set of ICC Field Notes (Val Map survey notes)?
> Ever seen a set of ICC Field Notes (Val Map survey notes)?
I'll bite. What do the field notes of what are in effect route surveys have to do with the problem of reconstructing an alignment from irregular, scattered evidence of different sorts and presenting that information in some readily intelligible, graphical form?
Kent, It Appears Your Suggestion Has Been Used Before
Get uppity like that over a reasonable reply and somebody may start another irrascibility thread.
I best not mention it that multiple scales have been used by engineers for hundreds of years to exagerate profiles.
Paul in PA, PE, PLS
They use the concept of one scale along the alignment and another to the sides. They even straighten out the curves. It's just engineering style mapping of station and offset. Same with most profile plans where the vertical scale is magnified. So it's a useful method in these kind of presentations.
So what is your scales 1000:1?
Kent, It Appears Your Suggestion Has Been Used Before
> Get uppity like that over a reasonable reply and somebody may start another irrascibility thread.
Well, the point that Leon seemed to be missing is that the double scale map is an excellent tool for picking out patterns along lines where the evidence isn't all along nominally the same line but falls on different offsets. That is the real value of the tool for boundary retracement and mapping.
> I best not mention it that multiple scales have been used by engineers for hundreds of years to exagerate profiles.
The earliest mention that I've seen of the double scale map for boundary analysis is in Mulford. I don't recall finding the technique mentioned in any earlier surveying text. If you have an earlier cite, I'd be interested to know of it.
> They use the concept of one scale along the alignment and another to the sides. They even straighten out the curves. It's just engineering style mapping of station and offset.
Yes, what you're describing would be fairly standard for route surveying, particularly along some existing alignment like a railroad track.
Route Surveying, Canals Predate Railroads
My 1882 "Engineer's Pocket-Book" even includes a reference to profile paper available in rolls instead of sheets for longer profiles. I can recall one of my first problems in AutoCAD 10 was to print out road profiles on extra long 24" roll paper. I had several that exceeded 24' and worked on them like scrolls.
I have no information if the Romans drew profiles for aqueducts, but do know that canals where grades of 0.1% or less were used required greatly exagerrated scales.
Paul in PA, PE, PLS
Route Surveying, Canals Predate Railroads
> My 1882 "Engineer's Pocket-Book" even includes a reference to profile paper available in rolls instead of sheets for longer profiles.
I'm afraid you're completely missing the point of this post, which I hadn't thought to be Raketenwissenshaft. In a situation where a land surveyor is trying to recover an old line and the evidence of that line is in the form of fences or other features that are at various undetermined offsets from the line, linear regression is fairly ineffective as a tool to find the line.
What can be remarkably effective is to make a double scale plot of the evidence in relation to some arbitrary baseline that is merely a best guess as to the direction of the line sought. The offsets are plotted at sufficiently large exaggeration of scale that measurements can be scaled at meaningful accuracy. For example, being able to scale widths between features of right-of-way fences at an accuracy of +/-0.5 ft. may be perfectly fine.
Then, by eye and scale, the line that best fits the evidence can be identified and drawn and the whole works recalculated. The eye can detect the pattern, separating the extraneous chaff (of which there is often no shortage in this life) from that which actually perpetuates the line in some fashion. The diagram that I posted above is the clean final version of the results, not the initial working plot.
Route Surveying, Canals Predate Railroads
It appears to me that you have original end points (monuments) at points 209 and 213. Definitely not a situation to analyze with linear regression but, to show how far the fences are off, great depiction map.
Route Surveying, Canals Predate Railroads
I think 209 is a set monument.
It looks arbitrary to me.
What I see is 209 was set where the side line intersects the fence?
Other than that if I was Judge Judy I would have a lot of questions for Kent.
Edit: maybe 207 was held.
Route Surveying, Canals Predate Railroads
On further review, yes the inner circle is open on 209. It was the outer circle that threw me off.
Route Surveying, Canals Predate Railroads
> I think 209 is a set monument.
>
> It looks arbitrary to me.
>
> What I see is 209 was set where the side line intersects the fence?
>
> Other than that if I was Judge Judy I would have a lot of questions for Kent.
Actually, 209 is where the corner was finally found after the analysis of the road fences. It was the remains of a rock mound that was almost certainly built in about 1870 to mark a corner of a land grant that was originally protracted at the time of the original survey in 1838. The original 1838 surveyor called for no mark at the corner, describing it merely as a certain corner of a survey that had been made in 1835. However, the 1838 surveyor later stated that he was grossly mistaken as to the true location of the earlier survey and had in fact not visited it in the course of his work. That left the corner to be located entirely by course and distance from other corners that he did mark on the ground more than 2.6 miles EAST and SOUTH of the corner in question.
The road location was an important part of the identification of the 1870's rock mound at 209 (which was actually not a very good attempt to locate the 1838 surveyor's protracted corner) because of the early date that the road was established (about 10 years after the rock mound at 209 was built).
Route Surveying, Canals Predate Railroads
Good for you Kent. You even considered a fence as some sort of evidence of some past survey. What ever evidence or analysis gets a surveyor to the right spot is great.
Route Surveying, Canals Predate Railroads
> You even considered a fence as some sort of evidence of some past survey. What ever evidence or analysis gets a surveyor to the right spot is great.
In that case, certain of those fences shown were most likely built in the 1880's. It wasn't that they were fences, but that certain of the fences had obviously been built to a line that had been surveyed and that the survey was made at a time when it was reasonable to think that the location of the line as run in about 1870 was well marked on the ground.
The other excellent clue was the actual direction of the line itself, which was more than a degree off the record bearing but consistent with the bearings of other lines that the 1870 surveyor had reported running in the area.
Route Surveying, Canals Predate Railroads
So was 213 set or found?
I'm not familiar with your symbology. The convention here is filled in symbols are found and open symbols are set.
Route Surveying, Canals Predate Railroads
> So was 213 set or found?
No. 213 was a rod and cap that I set at the center of a stone mound I found. That stone mound is what has been recognized since at least the late 1860's as the stake and mound set in 1838 to mark a particular corner. In my opinion, it is so consistent with what is known of the 1838 surveyor's work that it is quite reasonable to take it to be his corner.
Route Surveying, Canals Predate Railroads
That map reminds me of a Robert Frost poem...
"Down the right-of-way wandered
Mustache upon the lip
Tilley upon the head
The man who ciphered this way
And that way
Pointing to the mound of stones
Proclaiming affirmation as it was
Set by the man from
The late happier age"
Route Surveying, Canals Predate Railroads
> That map reminds me of a Robert Frost poem...
The real story is fairly interesting. The larger picture of which the line shown in that diagram is a part has been pieced together over more than ten years and at least ten different projects distributed over much of the area covered by the 1838 surveyor. No Tilleys were involved in that production, however. :>
Route Surveying, Canals Predate Railroads
Does Texas have any Corner Record filing/recording requirements? I'd be required to file a record if I done that.