Sometime back I reported on my Smith Lyraphone pushup piano play
of circa 1900, and I was wondering about the reason behind the
varying spacing and width of the tracker bar slots.

This is a 65-note unit, and the roll width is 13-1/4 inches.  There
are four different hole widths (rectangular slots), which get wider
the farther you get from the center.  The narrowest slots are 0.16"
wide and the widest are 0.28" wide.  The question was, "Why did
they do this?"

I found the answer.  The only patent date on the machine is stamped
into the wood tracker bar: Nov. 13, 1900.  I didn't know if this was
for the machine itself or just for the tracker bar.  So I went to the
US Gummint patent web site and started searching.

The earlier patents won't search by word; they require a category or
the patent number.  By randomly picking patent numbers I found the
patent numbers for the date this particular patent was issued, Nov. 13,
1900.  There were more than 600 patents issued this day.  So I went to
the classification area and tried searching for all patents issued
under Classification 84 (Music).  Some 21,000 hits came up, listed
chronologically.  With my earlier determined patent number spread for
Nov. 13, 1900, the list was narrowed down to just a few.

The pertinent patent number turns out to be 661920, entitled
"Self-Playing Musical Instruments and Notesheets Therefor," Inventor
James O'Connor, of New York.  This patent is for the variable-width
tracker bar holes.

The patent explains that expansion and contraction of the note-sheet
(the music roll) due to humidity changes is a problem, especially for
wide note-sheets.  Therefore, the apertures in the tracker bar need
to be increased in width as the distance from the center is increased.

It is further stated that there is sufficient aperture width to allow
for lateral movement (poor tracking) of the music sheet.  It is stated
that mis-tracking up to one hole width of the paper and full expansion
and contraction of the paper due to humidity can be accommodated.
Apparently this was considered necessary with no tracking device,
a wide music roll (13"), early paper and varying climatic conditions.

I can imagine that a special machine had to be set up to punch the
rolls.  Apparently this particular idea was the solution to a problem
that didn't exist -- nobody else that I know of bothered to buy
the idea.

Mystery solved.

Ray Fairfield

 [ See  http://mmd.foxtail.com/Pictures/PwrRoller/lyraphone1.htm
 [ -- Robbie