Don Barone Wrote:
-------------------------------------------------------
> Just before you go Warwick perhaps you could
> explain to me and the others how and why they were
> able to complete each individual course to within
> a couple of inches on all fours sides but then
> could not repeat it on the next level
> ...
>
> Don Barone
>
> “Coincidence is God’s way of remaining anonymous.”
> -Albert Einstein


The thickness of the each course is the variable....they are/were all planed flat to prepare for the next level. Maintenance of the square of each successive course is another matter.

No rocket science involved

Warwick

" I have always found that the main obstacle to free
association on these boards is the broad
misconception that what we do not know is more
significant than what we do know."

Warwick L Nixon, March 8, 2019