Re: "Welte-Mignon Recording Technology", 031112 MMDigest

Mercury hazard at Welte studio

John A. Tuttle asked, "If the carbon rod was suspended over the mercury
until such time as a note was struck, wouldn't there be a spark when
the two elements came in contact with each other?  And, if that was the
case, wouldn't that create mercury vapor -- which is extremely lethal
to humans and other living organisms?"

Not quite so.  Mercury does not kill quickly.  The presence of the
vapor in the air allows it to build up in the body, where it affects
the central nervous system.  Certain mercury compounds are much more
poisonous than the elemental metal.

Mercury has been mined in Spain for centuries, and the miners (in more
recent times) are closely monitored.  I think each miner has two jobs,
the second job having nothing at all to do with mercury mining.  If the
miner shows above a threshold level, or has worked the allowed number
of hours, he goes to his other job for some time.  (All this is from
memory and not looked up on the Internet, from which there is certainly
bunches more information and misinformation.)

I'll bet the rods did make and break contact with the mercury.  The
alternative, continuous but varying submersion, could never capture the
instant of striking the key.

Mercury poisoning results in madness.  Do we know if any of the Welte
people exhibited symptoms of mental unbalance?  (Other than the usual
weirdness that all of us mechanical-musical-instrument people already
have.  Melville Clark, for instance, was obviously a computer hacker
misplaced in time.)

Peter Neilson

 [ Mercury switch alternatives are discussed in articles indexed at
 [ http://mmd.foxtail.com/Archives/KWIC/M/mercury.html  -- Robbie