[ Editor's Note:
 [
 [ Last August Matthew Caulfield sent to me and David Wasson this
 [ description of the Wurlitzer perforator and its automatic tempo-
 [ compensating mechanism.  The Wurlitzer master rolls, to our
 [ understanding, were punched at constant "steps-per-beat".  The master
 [ roll was pulled by a capstan reader at constant speed (hence constant
 [ tempo), and the perforator's tempo-compensating mechanism pulled the
 [ output paper at continually increasing speed, just as though it was
 [ accumulating on a take-up spool at constant shaft speed.
 [
 [ Robbie Rhodes

There is a push rod moving back-and-forth horizontally which ratchets the
gear which moves the tractor device which pulls the paper layer through
the perforator under the jaws of the perforating dies.  Each cycle of the
machine and each back-and-forth motion of the push rod advances the paper
approximately half or three-fifths of a punch.  The push rod does not
connect directly to the ratchet gear wheel but is threaded to move up and
down a long (about 8-inch very finly threaded rod which is attached to the
side face of the gear wheel.

When the operator starts to perforate a roll, beginning at tune 1, he
turns the crank on the head of the threaded rod so as to bring the push
rod all the way to the top of the threaded rod.  Thus the travel of the
push rod moves the gear wheel to its most minimal degree, whereas when the
push rod is in its lowest position, closest to the center axis of the gear
wheel, each motion of the push rod turns the gear wheel to its maximal
degree, advancing the paper to the maximum extent.  This is the position
the machine finds itself in when it is punching the last few feet of a
ten-tune roll.

Each complete cycle of the perforator performs many operations, one of
which is to turn, by means of another ratchet, the same finely threaded
rod the operator set to its starting position, in the opposite direction,
each ratcheting out of the thousands needed to perforate a complete roll
having the effect of miscroscopically increasing the paper travel at each
cycle and correspondingly lengthening the size of each perforation.

Thus, as was told to me, the operator sets the tempo conpensation device
only once (at the start of a roll); everything thereafter is done by the
machine.  Any master can thus be used anywhere in the series of ten tunes
making up a roll.  However, to normalize the tempo of all tunes to some
universal standard, no matter how large or small spatially and lineraly
the arranger marked the measures on the master, a "gear" system is used,
each master being marked as being of a certain "gear" ("use 48 gear" or
"use 32 gear").

No actual gears are changed.  There is merely a lever on the side of
the perforator, with a pointer to a scale with numbers on it indicating
"gear"--much like the tempo scale on a player piano.  Each time the
operator put a new master on the perforator, he sets the "gear" pointer
to the proper number before starting to perforate.  That's all there is
to it.  The gear setting then controls the speed of the master past the
index rods that mechanically read the master.