Jeff  wrote:

> The principal function of jointing is to create the essential flats, the
> guides by which we work.

GG

I believe the function is to get all the tips in the same line so they all
do the same amount of work.  Think of jointing then sharpening - then the
saw gets dull.  All of the teeth are still in the same line and it does no
need to be jointed before sharpening.  After a couple of sharpenings some of
the teeth are no "taller" than others and jointing will help.

But what do I know?

Ed Minch