Edison phonograph cylinders

Barbara Appelbaum's comments regarding checking AATA for references
to wax cylinder conservation is well taken.  In this case, however,
I doubt that the limited and often obscure literature on Ediphone
cylinder conservation or transcription has been cited in AATA.  In
addition, unfortunately, much of the most successful experience in
this field has not been published.

The cylinders are, indeed, attacked by fungus and the residue is the
fungal mycelium.  The fungus feeds on and etches the surface,
sometimes to the degree that the sound information encoded in the
grooves is lost or severely damaged.  Ediphone cylinders use a
hill-and-dale coding method (vertical variations of the bottom of
the groove) so that any additional or extraneous pitting (from
fungus or mechanical damage) reproduces as noise.  Extensive damage
can destroy the groove geometry so that mechanical pick-up styli
will not track properly.  There are, however, non-mechanical
transcription and signal restoration techniques that have been
developed and are in the process of development outside the U.S.

Although most of us who have worked with this media consider the
cylinders as artifacts, per se, the sound information recorded on
them is usually of greater importance than the physical cylinder
itself.  The cylinder continues to be of value, however, especially
as new technologies are being developed which can extract more
accurate and complete transcriptions than the techniques we used in
the past.

For the cleanest transcription of cylinders (as well as the best
preservation), it is necessary to remove all of the fungal body,
debris and dirt from the grooves.  Any such material left in the
grooves will reproduce as noise and may obscure any signal coding
that remains at the bottom of the grooves.  In my direct experience
with over 3000 Edison and Dictaphone cylinders, both "amateur" and
commercially produced recordings, I did not run into any problems
with the washing technique I described in a recent posting, nor were
any problems reported regarding the additional 16,000+ cylinders for
which, I believe, this technique was adopted.  There were hundreds
of proprietary (and often small production) formulations for these
cylinders, however, so one must be ever cautious!

Clara Deck is quite right in recommending against re-use of the
cotton wadding packaging.  I would add that cylinders should be
stored in non-hygroscopic or minimally hygroscopic materials (see my
prior posting) in moderate RH below 50%.  Most of the mold damage we
see is directly attributable to the high-RH microclimate created
around each individual cylinder by the hygroscopic cotton or wool
wadding.  This situation was often compounded by an overwrap of
glassine paper.  I was able to correlate degree of fungal damage
with original packaging method for the 3000 cylinders that I
processed, and I believe that others found the same relationships.

Geoffrey Brown
Curator of Conservation
Kelsey Museum
University of Michigan
Ann Arbor, MI 48109-1390
313-647-0439

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                  Conservation DistList Instance 10:43
                Distributed: Thursday, October 31, 1996
                       Message Id: cdl-10-43-003
                                  ***