So, I spent most of this week in West Texas and among the things I did was some research for a lot survey in a small town in the mountains. The lot is in an addition laid out in 1883 and when the original surveyor platted it, he very considerately informed posterity what the bearing basis of his survey was by giving ties from the SE corner of Lot 1, Block A to:
a) the North corner of a Catholic church (still standing about six-tenths of a mile away) and
b) the South end of this topographic feature described as "Mound Hill" that was about three miles off.
Naturally, there are now intervening buildings and other features, so it will take a bit of work to determine the grid bearings of the lines to the corner of the church and to the South edge of Mound Hill. We can cheat and use GPS in the case of the Catholic church, I suppose, but not for that of the hill. The edge of the hill will have to be triangulated through openings in what has grown up or has been built up since 1883 and it will have to be done in a way that the result is as reasonably close to what could be obtained from the lot corner as may be had.
How tall are those trees / buildings Kent?
You might be able to build a temporary Bilby Tower using rental scaffolding and get a direct viewpoint, rather than traversing to where you can see from the ground.
> ... it will take a bit of work to determine the grid bearings of the lines to the corner of the church and to the South edge of Mound Hill.
Save yourself some time and work. It looks (from the picture) like you have a good fence to use.
😛
> How tall are those trees / buildings Kent?
>
> You might be able to build a temporary Bilby Tower using rental scaffolding and get a direct viewpoint, rather than traversing to where you can see from the ground.
Well, I'll certainly keep that suggestion in mind. The tie to the South end of Mound Hill won't be that difficult, I don't believe. It can be done by triangulation from stations near the corner in question and a bearing calculated to the feature from the corner, the work of perhaps half a hour.
As for the corner of the Catholic Church, we'll most likely traverse to it to make the tie by calculation with a GPS vector to check the spur line that will be run. I'm thinking that'll go fairly quickly.
Part of the point of the exercise is to compare the orientations of a couple of buildings that were evidently constructed within a year of the platting of the subdivision to the bearing basis derived from the bearings taken at the lot corner to the church and hill and then back into where the "large rock" marking the section corner fell, to see if it is still in place under the pavement.
> it will have to be done in a way that the result is as reasonably close to what could be obtained from the lot corner as may be had.
reasonably close?
I can't wait to hear what that is going to be.
😉
I have discovered here that the old RC Church properties are a real PIA to get a grip on. They kind of had 'carte blanche' in anything that they did and avoided a lot of the recording at times.
No one was going to question anything that they did in a legal fashion. It would have been considered sacrilegious in a way at the time.
I am always surprised at the depth and breadth of research for your surveys. It is very refreshing in these times when I am finding out that local surveyors are doing work for 1/2 the value that I place on them.
> Save yourself some time and work. It looks (from the picture) like you have a good fence to use.
This one is, at least on paper, even easier yet. There are several old buildings in the block and on an adjoining block. I've done a bit of research discover when they were constructed. A couple were built within a year or two of the survey of the subdivision.
I'm expecting that the bearing ties to the church and hill and the position and orientation of the oldest buildings will be consistent.
> > it will have to be done in a way that the result is as reasonably close to what could be obtained from the lot corner as may be had.
>
> reasonably close?
>
> I can't wait to hear what that is going to be.
Well, in this case "reasonably close" means essentially the same answer that I'd get were the feature directly visible at the corner.
> I have discovered here that the old RC Church properties are a real PIA to get a grip on.
In this case, it doesn't look like much of a trick. I've found a historical photo of the church from the period in question and can verify the present structure against it.
> In this case, it doesn't look like much of a trick. I've found a historical photo of the church from the period in question and can verify the present structure against it.
Good luck if it is built where it is supposed to be built .
A lot of times here there were various donations to the archdiocese that were held in secrecy and sometimes they built where they wanted to build or felt that it was most advantageous.
Remember the Alamo. 😉
gotta skedaddle now. Busy day but why oh why on Fridays.
> > In this case, it doesn't look like much of a trick. I've found a historical photo of the church from the period in question and can verify the present structure against it.
>
> Good luck if it is built where it is supposed to be built .
Well, the situation is that the church was in place in 1883. It doesn't matter so much where it should have been built as where it was. I just need to verify that the North corner of the church building that I identify in 2010 is most likely the same corner sighted by the 1883 surveyor and that looks to be true.
How do we know someone didn't come along and kick that church over 0.18 foot in the intervening years?
😉
Kent
That picture reminds me of my days surveying on the moon; except the moon had more trees.
Darn...
Perry beat me to it...
Question:
Are there PEOPLE in West Texas?
> How do we know someone didn't come along and kick that church over 0.18 foot in the intervening years?
Well, after Vatican II, didn't the Church move to the left?
Darn...
> Are there PEOPLE in West Texas?
I guess you Easterners are used to being able to ask someone where the boundary is? :>
> We can cheat and use GPS in the case of the Catholic church, I suppose, but not for that of the hill. The edge of the hill will have to be triangulated ...
What type of equipment and what level of precision do you expect that the 1883 surveyor used to make the bearing ties to the hill and church? How close do you expect to have to locate these two objects to make a "proper" comparison? Could you "get by" with a hand-held GPS position or map scaling to make the confirmations you seek? Have you located the 1883 monument the bearings were taken from?
JBS
Darn...
One of these days, I'm gonna come out there and you can show me how to survey land over 10 acres....
Kent
> > Are there PEOPLE in West Texas?
>
> I guess you Easterners are used to being able to ask someone where the boundary is? :>
Kent, we don't even have to ask. The people have been piling debris, stones, and junk piles along the property lines for years. We just wander around in the brush until we trip over some of the junk or get a barb wire scar and then we have our POB. Then we get out the compass and follow the line of junk, hanging flags as we go, until we see some scars on the trees or an old axle, then we turn left and start looking again. Pretty soon we end up back at the starting point and the survey is done. We do sometimes use GPS, but only to find the beer joint after work.
>? Could you "get by" with a hand-held GPS position or map scaling to make the confirmations you seek?
No. One should expect to find from experience that there is absolutely no substitute for actually measuring the bearings to features like the south edge of the rimrock on a hill from nearly the same vantage point as the original surveyor had.
What that means in practice is taking bearings from points straddling the original line of sight (if the point from which they were taken has been obliterated as seems to be the case here), locating the feature by that triangulation, and calculating the tie that would be made from points between the straddling stations. The distance to the feature won't be very good, but it will be more than fine for the inverse calculation of the bearing tie to any point on a line lying between the rays observed in the triangulation. I've used this technique in many cases and find it superior.
Kent
> Kent, we don't even have to ask. The people have been piling debris, stones, and junk piles along the property lines for years.
So, you just ask whether you're on the right piece of land and take it from there? I can see how scary West Texas work would be. :>
