This is a good read.

To hear an ailing 82-year-old Thomas Edison speak, with the great inventor's voice, wheezy and high-pitched, growing husky and choked as he praised his good friend Henry Ford who stood alongside President Herbert Hoover on a stage on Oct. 21, 1929 is catching lightning in a bottle.

Earlier that night, the crowd heard Albert Einstein offering words of praise for Edison in German from Berlin.

It is contained in one of the world's oldest surviving radio broadcasts, recorded on an obscure machine that General Electric developed in 1922 and called a pallophotophone -- which means "shaking light sound" in Greek.

Listening to the elderly Edison lose his place, become confused and nearly weep over the depth of his admiration for Ford more than 80 years after he spoke those heartfelt words to a live audience has the power to cause a lump to rise in one's throat.

This aural treasure might have remained lost in history's silent dustbin were it not for a curious archivist, a dogged engineer and a fixer.

And here’s the payoff.