This is a Grenzstein. Thats the german word for corner stone, or the stone that marks the corners of a piece of land. As a surveying technician these stones are elementary for my work. This stone isnt buried that deep. But thats a rare case, alot of stones, mostly older ones are buried as deep as one meter or three feet. The yellow cross marks the middle which is defined by a certain set of coordinates. I did the cross, though.
For something to become buried even as shallowly as that one can take many years, but surely the ones a metre down must either have been there for a few centuries or earth has been dumped over them at some time?
That is correct. Although, misplacement doesnt seem to happen very often. Its just that earth and the ground move over decades, and with rain and whatnot some differences occur.
I think its rather important for mathematical understanding. Mine isnt too good, Im more keen on words. Although I wanted to try something I knew I wasnt good at.
