DND ASE pin / stake found

[maple_leaf_eh]

Originally Posted by Bruce Parker

Can you explain a little further what you mean by a 'topographical' marker?

I think you may have a few members out there scratching their heads over the term 'cadastral' but it's just a fancy way of saying land parcel or lot boundaries. Most cadastal and even control survey monuments are steel with brass or bronze identification caps. I've never seen aluminum and wonder how well they would stand up being pounded into the ground. That, plus the ablilty to locate them with a typical survey 'bar finder' (or in the old days a 'dip meter') which operates on an iron/magnetic principle.

I try to stretch my vocabulary within the bounds of common speech. Scientists have their terminology, as do vehicle restorers.

Anything aluminum would be there as weatherproof, but as you say not be a permanent legal marker. Ferrous metal, ie "iron bars" of old, are the preferred enduring way to indicate agreed points. The two houses I've owned have had 3/4" steel bars somewhere at the extremities of the property lines.

Topographic survey is for maps. Draw big areas without necessarily worrying about the smaller parcels. I subscribe to an online magazine called, American Surveyor, and some of the tale the professionals tell are wild. One fellow wrote about having to prove the boundaries of a particular property north of San Francisco so an estate could be settled (http://www.amerisurv.com/PDF/TheAmer...1_Vol9No10.pdf and http://www.amerisurv.com/PDF/TheAmer...2_Vol10No1.pdf). The same sorts of problems arise with larger administrative boundaries. Military surveyors were called in to 'collect' the boundary between the three warring entities immediately after the Dayton Peace Accords for the Former Republic of Yugoslavia. Imagine tiptoeing, bold as a canal horse through the no-man's land of a civil war? The so-called Inter Entity boundary line is now the defacto border between Bosnia-Herzegovina and Republika Srpska (https://en.wikipedia.org/wiki/Inter-..._Boundary_Line). I knew surveyors who were on that job.

The business of borders gets interesting in other parts of the world. Based on which definition of the shape of the world a country chooses, some interesting occurrences arise. Pakistan has a sea level coast. It uses an Earth-centred geodetic datum. Afghanistan is landlocked. They use a surface point of origin for their maps. Mathematically both are acceptable places to start, except a measurement that begins at the centre of the Earth has fewer human induced errors, and is more widely accepted internationally. There are places on the AF/Pak border where each claims territory inside each other's boundaries. In some cases by hundreds of metres. It doesn't help that the science of this mathematical discipline is frightfully complicated, with propagation of error of tenth and twelfth decimal places equalling the magnitude of difference of shooting distances on the surface. And the world is not uniformly uneven either, not is the sea level! Fortunately, every country has a few distinguished academics who worry about borders more than the rest of us, and there are international conventions of settling boundary disputes (https://en.wikipedia.org/wiki/Territorial_dispute).