Yep, I owe John Grant a few "Miller's" for losing a hasty wager!

Whether or not the system was really intended to maintain constant
tension of the roll might be explained in the transcribed diaries
and recollections of Dr. Clarence Hickman, who developed the
Ampico B.  I believe AMICA has now published these papers -- can
someone check for us?  I heartily agree that the purpose is to
alleviate "skidding".

I just measured a jumbo roll I mounted on a Klavier (now Keystone) core.
The diameter of the roll on the supply spool is 3.25 inches; the outside
diameter of the core is 0.86 inches.  If a simple "pressure pad" brake
(constant torque) were employed, the tension of the paper would vary more
than 4.3 to 1.  I don't think 10-tune music rolls have a problem like this,
because orchestrions use a large diameter core.

(Gosh... Remember the problems we had with cheap 7-inch reel-to-reel
tape recorders?  And they had very little friction at the "reader head"!)

-- Robbie Rhodes