S. K. Goodman asked:

> I wanted to know if anyone has had negative experiences of torn rolls
> or tracking problems with the Aeolian left-ear-only tracking system?

A disaster with the ordinary public, yes, because wide or narrow
rolls _must_ be adjusted for each time.  But for intense pebble-glassed
player fanatics like me (I speak figuratively), a boon, because you can
tweak the ear and play those badly-made Aeolian-American rolls of the
1960s (and not a few QRS rolls of that period too) that are cut with
the notes half a perforation to the right.

Once the user is trained to it, the single-finger (SF) system is fine.
The sideways sliding of the roll drive spindles must be lissome and easy
(I use Vaseline with graphite in it) and the return spring well matched
to the single tracking pneumatic.  There is no dead position: the
pneumatic is always pressing against the spring with the roll
controlling its force.

There should be a second little pneumatic operated from the main stack
suction to pull off during play a spring-loaded "centralize roll"
latch, which lifts up, traps a screw on the tracker in a V notch and
prevents wander during reroll.  (The tracker pneumatic is left on
suction so that its movements assist the screw into the notch.)

SF plainly wasn't a commercial success.  Judging from the instruments,
Aeolian kicked off its 88-note instruments in 1907 with manual tracking
(up-and-down lever on the right of the spoolbox, which you snatch at
desperately as you play), then obviously got complaints and toyed with
the multi-slot Philipps system from about 1909 onwards, then started SF
in 1910.

All the pianos/pushups I've seen with SF tracking, including my own,
have been dated 1910 to 1912, though it's possible they started earlier
in the USA.  Quite a few of these showed signs of having started off in
the factory as manual trackers, as the tracking gear is screwed down
over patent labels.

Obviously more nausea followed from the ignorant public, as double-
finger (DF) starts around 1912 and, in Europe, overlaps for many years
from 1923 or so with the Standard four-hole system (which Julian Dyer
is possibly the world expert at describing, for the benefit of those
many restorers who can't believe the correct tubing is correct).

I have a German-assembled "Ibachiola" (Rudi Ibach Sohn, with Aeolian
action) upright with DF tracking, made as late as 1927.  Duo-Arts seem
to have gone on late with DF, too.

Having seen it working, I would vote for the Philipps system as being
customer-proof and untinkerable-with, but it would have to have some
automatic self-cleaning facility to be really reliable.

Dan Wilson, London