No tape measure! No calculator!! Euclid and his Geometry in the real world!
Old timey carpenters were not always “book learning smart” or patient enough to
read some manual or instruction sheet in the way required of modern carpenters.
But they did have a firm grasp of classical arithmetic and geometry in a way that
seems to have completely disappeared from the modern construction project.
The contemporary outdoor deck balustrade seems to be one of the most obvious
casualties of this absence of classical geometrical knowledge.
With nothing more than a piece of cardboard or 15lb felt or even sheetrock or
(now) tyvek, the old timey carpenter could take some scraps of wood and a pencil
and lay out a perfectly symmetrical, evenly spaced balustrade regardless of the
length of the interval between the railing posts in just a few minutes.