>From tinfoil phonographs to light bulbs, Edison made things that were
practical and worked.
If one does not realize the difficulty of Edison's inventions then one has
not attempted to duplicate them. Has anyone ever played with a reproduction
Bell telephone? Mine required shouting so loud that the person in the next
room could hear me better through the wall than through the Bell telephone.
It was Edison's carbon microphone that made it practical.
As a retired Physicist and Physics teacher, I remember fondly of trying to
make a tinfoil phonograph using the plans from the Edison Institute Ford
Museum. Just the machine tool technology is impressive for today. Has anyone
else on this list made a mandrel shaft and feedscrew for a Home, Triumph, or
M class? I spent weeks last year doing just that. The 100 thread per inch
buttress thread of the feedscrew is not easy to do. The tapered brass
mandrel is an odd taper and I had a number of failures before I got one that
was
perfect. Only a few thousandths of an inch of slop in your taper attac
hment and you are in trouble. My reproduction of the original tinfoil machine
has never been completed because I became frustrated with my recording and
playback styli. Just this week I am seeking the counsel of the most
knowledgeable tinfoil expert in the world.
When it comes to electric lighting, I have a San Francisco Market Street
arc lamp in my collection. It draws 20 Amps at 80 Volts when struck, that's
1,600 Watts, and the carbon rods quickly burn out. Many years ago when
teaching electrical circuits I had a setup to place a filament (a term coined
by
Edison as I recall) inside a bell jar that could be evacuated. Trust me,
getting anything to last at incandescent temperatures is not easy, even today
with all the knowledge we have. My students then had never given thought to
the simple and ubiquitous light bulb. Usually they were enthralled by the
warm glow coming from the bell jar.
Many phonographic items were invented by Edison but he never got credit for
them. Remember when the 'elliptical stylus' was introduced to play stereo
LPs and was hailed as a great leap forward? What do you think the contact
area of a 1902 Model C sapphire stylus is? Remember the switch from sapphire
to diamond styli in the 1960s as playback equipment improved? That too was
hailed. Linear tracking? Microgrooves?
All the best Independence Day wishes to everyone,
Al
The price of Freedom is always paid in blood. Thank a veteran today.
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