[ This is the concluding article of the correspondence from Dr.
 [ Clarence Hickman to his great niece, Judy, provided through the
 [ generosity of Dr. Hickman's family and MMDer James Brady.

June 3, 1978
Dear Judy:

I was happy to hear that you enjoyed hearing the Model B Ampico.  I
realize that it was a great improvement over the Model A.  Several of
the members of AMICA, after the publication of Larry Givens book, seem
to think that I was a wizard and they give me credit for more than I
deserve.  I would like to set the records straight.  When I joined the
American Piano Company Research Laboratory I had a fair knowledge of
physics and mathematics, something that the designers of players and
pianos did not seem to have.

As an example, the selection of strings for a piano was test and try,
with the result that string tensions ran from 200 pounds to as much as
300 pounds.  Many years ago, the great German Physicist, Helmholtz (I
got my doctor's degree under A. G. Webster, who in turn got his degree
under Helmholtz) designed the strings for a piano that gave even tension
in all strings, about 150 pounds per string.  No one that designed
pianos after that seemed to be able to do what Helmholtz did.  They used
his piano and when they changed the size of the piano they selected the
strings by extrapolation.

When I joined the company in 1924, Mr. Stoddard had in mind the
development of the Model B Ampico and had three important changes that
he wanted to incorporate: [first,] make the player so it would take long
rolls.  This called for making the take-up spool larger and making the
recording take-up spool the same size.  There was no difficulty in doing
this.

Next, he wanted to use an electric motor to drive the roll instead of
the air motors used in the past.  Using an air motor, it would often
slow down when large quantities of air was being used to play the notes.
With my knowledge of motors this was not a very hard problem to solve.

Next he wanted to make it possible to change the air pressure much
quicker than was possible with the Model A.  When an artist plays three
or four notes with the right hand, the top note is usually the melody.
He can, with dexterity, play the top note louder than the others.  This
is not possible with a player.  In order to play the melody note louder,
it was necessary to advance that note on the roll and then lower the
pressure to play the other notes.

The mechanism for changing the pressure was so heavy that it took
considerable time to change the pressure, so the note had to be advanced
so far that it results in a broken chord.  He wanted to speed up this
system and proposed using discs instead of three pneumatics on hinged
boards.  (The use of the three pneumatics placed in different positions
made it possible to get seven different loudnesses by the pneumatic that
was activated or by activating two or three).

We made such a device and it reduced the inertia of the moving parts to
one-tenth that of the Model B.  However, that was still not enough to
suit him.  I then came up with the curtain control system used in the
Model B.  This reduced the inertia of the moving parts to one-thousandth
of that in the Model B.  This pleased him very much.

He also wanted to be able to record the loudness that each note was
played by the artist.  This had never been done.  They had musicians
listen to the artist and he put in the loudness from memory.  This
system resulted in the loudness being adopted that pleased the one doing
the listening rather then the artist.  I came up with the method of
measuring the velocity of the hammer of every note and this solved the
problem

Back to the opinion of some AMICA members.  You may remember that
Maryanne Schumm is using my contributions to archery as a thesis for her
doctor's degree.  She had to get the approval of five of her professors.
There was one that bucked and had not given his approval.

She wrote up a record some of my achievements in other fields and
included my contributions to the piano industry.  He called her in and
asked if this C. N. Hickman she was talking about was the same that
developed the Model B Ampico.  She said I was, and he said he would
approve, for he was a member of AMICA and had read of my contributions
in their bulletin.

I really do not consider that I did much more than anyone could have
done who had a fair knowledge of physics and mathematics.

Clarence

 [ Editor's note:
 [
 [ All who spoke with Dr. Hickman remember the same modesty which is
 [ expressed in his letters.  But he had several noteworthy attributes,
 [ including an inventive mind and the desire to test and measure and
 [ quantify with numbers.
 [
 [ The inventors of the Welte-Mignon system, Edwin Welte and Karl
 [ Bockisch, might have been like Hickman, but in 1905 Germany secrets
 [ were closely held, and we know virtually nothing about the engineer-
 [ ing development of the Welte-Mignon.  Hickman was trained as a
 [ scientist and he kept a diary of his experiments and thoughts,
 [ which gives us today much more insight into the Ampico piano than
 [ any competing system.
 [
 [ Larry Givens preserved Hickman's journals and they are included in
 [ the book, "The Ampico Reproducing Piano", published by Musical Box
 [ Society International.  It gives a good view of scientific method-
 [ ology in engineering product design.
 [
 [ -- Robbie