When you were schooled about geographical correction lines? It was in no curriculum,but one teacher felt he should cover it…Im not jabbing the flat earners here…

Are you talking about correction lines on a large scale like on a globe or small scale like property lines? I guess ultimately, they are basically the same.

Every 6 miles there might be a jog in a longitudinal line….sometimes resulting in short forties and government lots.

Yes, every township has one. There is one on my Southern property line. Then we get into "declination" (I think that is what it is called). The property lines established here 50+ years ago have "moved" to the West. On my far East property line that amounted to about 60 feet. Property lines and fence lines no longer match up. The lines on some small lake lots moved enough that part of peoples homes or cabins are no longer on their property. I will wait for Zim to chime in with a better explanation.

If surveyed correctly the first time using true north, property lines will not move. Magnetic north does change over time but not true north. The original government surveyors would take a bearing on the North Star every night it wasn’t too cloudy to do so to keep their true north bearing.

Crap, I’d say grade 7 or 8. Wasn’t like it was on a test or anything, just something the teacher pointed out.

The age has not yet come for me

I refer to that era as my "senior year".

Can't say as I don't ever remember any linage lessons in school !!