Robbie asked if I have any documentation to prove that the 88 note
trackerbar scale actually came from the printing trade.  I have to say
I don't, but it's a pretty good guess, and maybe somebody out there
knows the story in detail.  However, here is where I'm coming from.

Melville Clark was responsible for the 88-note trackerbar.  He started
selling players and rolls for it in 1907.  As I understand, they wanted
to get all 88 notes on a standard width roll of paper, commonly used by
the printing trade.  The uncut paper width was from 11-5/8 to 12 inches
wide.  They would center the perforations on the paper by trimming each
edge for finished width 11-1/4 inches.  Then they looked around for a
scale that didn't have to be modified.

We were both wrong about the name of the scale, by the way.  A pica
scale is 6 to the inch, not 9.  The Agate scale is 5.5/in (14/in), used
for classified ads.  The pica scale is .16604 inch.  The newspapers use
the non-parel scale (12/in).  The printer's standard of measure is the
point, .013837 inch.  This is the standard used to get 72 points to the
inch, which is 8 X 9, a multiple of the printer point.  (Granted, an
index head would do it almost exactly, and a scale engine would be
right on the money).

The 88-note trackerbar scale is almost exactly 706 points long.  The
9/in scale was used, I believe in some typewriters.  I have a 9/in
clear scale I bought at Office Max to check out letter spacing on a
computer screen, so I know this scale is used somehow in the printing
trade and was adopted for computer screens some way or other.

It's kinda like the question, "Where did our modern railroad gauge come
from?"  We have no absolutely direct proof, but are told it represents
the distance between the Roman chariot wheels, right?  That's because
anybody who owns a tape measure can measure them, and they're the same.
So I'm sort of using that kind of reasoning here.  Most perforators
were built by the same manufacturers who built printing presses, like
Meihle, and if Melville Clark had to ask them to retool for a handful
of proprietary perforators not expected to ever wear out, they would
still be paying for the retooling, I suspect.  They adopted a
reasonable standard that these companies used, apparently.

Craig Brougher