Karl Petersen said:

> Nylon, gutta-percha, acetate and nitrocellulose, available in the
> late 20s, were all more expensive and/or less stable.

Nylon not until the late 30's, and at that time it was expensive.  It
was first exhibited at the 1939 World's Fair.  No, I wasn't there.

Nitrocellulose is indeed not stable.  It varies between highly
flammable and explosive.  Not the plastic of choice.  If I'm not
mistaken, it smells of camphor if you shave off bits of it.  Is that
true?  Why?

There is a plastics museum in Leominster, Mass.  Their phone number is
978-537-9529.  For a historian, ask for Keith Lauer.  (He's not in this
week, though.)

The address is:

  Plastics Museum
  210 Lancaster Street
  Leominster MA 01453

Peter Neilson