While glass harmonicas have mechanical parts, they are _not_ a
"mechanical instrument" since they don't play themselves.  At least,
none that _I_ have ever heard of do.  They require human performers.

Glass harmonicas are still being made by the Finkenbeiner company,
using a modern quartz glass that probably sounds much better than
the stuff Ben Franklin used.  They have a web page located at

    http://finkenbeiner.bcn.net/

Be prepared for the prices: these are not cheap instruments.  I've
bought a number of CD's with glass harmonica music on it and been quite
pleased with the unusual sound, but more than five or six tunes gives
my wife a headache.  =)

regards,

Larry Smith