[78-L] Record your voice!

[David Lennick]

Michael Biel wrote:
> Ken "Silver Showcase" wrote:
>> Very interesting, David.  Do you have a year to go with this?
>>
>> -- Ken
>>
>>   
> 
> I wrote about these zinc discs over 30 years ago in Record Research!  I 
> pictured this one and a couple of others that seem to be the same with 
> different labels.  1922 seems to be about when the Echo Disc and about 
> five other brands hit the market. All but one had paper labels.  There 
> is one brand that is a little larger and has an engraved label.   
> Eldridge R. Johnson's son Fennimore wrote in his book that his father 
> had discovered this principle in the 1890s when using zinc masters.  
> What happens is that when you shout into a phonograph horn the needle 
> vibrates in the blank groove and makes slight indentations in the zinc 
> that can be faintly heard.  It is almost impossible to hear, it is not 
> permanent because playing it smooths it out, and the disc can be 
> reused.  These pre-date the ucoated aluminum discs but share a patent.
> 
> Michael Biel mbiel at mbiel.com

I know the principle has been discussed a few times here..I've turned up one or 
two "Kodisc" samples. Usable today as nail files or pumice stones.

dl

> 
>>> http://www.thoseoldrecords.com/A125/0003.JPG