On 04/21/2012 06:01 PM, David Lewis wrote:
> The rubber disc story comes from Gelatt. I have never seen one, and have
> never known anyone to encounter one, but that doesn't mean they might not
> have existed. I think that if you found one, it may not be playable by
> conventional methods no matter how hard it might have been originally
> because very old rubber tends to dry out and split.
> And I have no confidence in rubber as a viable playing surface.

Fred Gaisberg mentions rubber in "The Music Goes Round":

"Berliner had been using ebonite or vulcanised rubber for pressing 
records. Ebonite took a lot of pressure and would not retain the 
impression permanently. Pondering over this he remembered that the Bell 
Telephone Company had abandoned vulcanised rubber and adopted a plastic 
material for their telephone receivers. The Durinoid Company of Newark, 
N.J., were button manufacturers who undertook to furnish pressings on a 
similar substance from matrices supplied by Berliner. The new substance 
was a mixture of powdered shellac and byritis, bound with cotton flock 
and colored with lampblack. It was rolled under hit colanders into 
"biscuits." When heated, these "biscuits" were easily molded under 
pressure and when cooled they retained the impression. "

He doesn't give the year, but the general time period in the larger 
discussion is the 1890s. Also do keep in mind that Gaisberg's memory has 
been proven faulty in numerous instances (that, or he withheld or 
embellished things, perhaps to avoid embarrassing still-living subjects).

Read and Welch (in the 2nd edition of From Tin Foil To Stereo) also 
mention hard rubber Gramophone discs, and say that the discs had uneven 
shrinkage when cooling and also occasionally were ruined by gas bubbles 
on the surface. They, however, credit Gaisberg for both finding the 
Durinoid Company and for arranging for Durinoid to press records in 
their shellac-based compound.

Michael Shoshani