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N0KFQ > TODAY 09.12.15 16:42l 65 Lines 2946 Bytes #999 (0) @ WW
BID : 77034_N0KFQ
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Subj: Today in History - Dec 9
Path: IZ3LSV<IW8PGT<CX2SA<N9PMO<N3XPD<N0KFQ
Sent: 151209/1538Z 77034@N0KFQ.#SWMO.MO.USA.NA BPQ1.4.65
1921
GM engineers discover that leaded gas reduces "knock" in auto
engines
On this day, a young engineer at General Motors named Thomas
Midgeley Jr. discovers that when he adds a compound called
tetraethyl lead (TEL) to gasoline, he eliminates the unpleasant
noises (known as "knock" or "pinging") that internal-combustion
engines make when they run. Midgeley could scarcely have imagined
the consequences of his discovery: For more than five decades,
oil companies would saturate the gasoline they sold with lead-a
deadly poison.
In 1911, a scientist named Charles Kettering, Midgeley's boss at
GM, invented an electric ignition system for internal-combustion
cars that made their old-fashioned hand-cranked starters
obsolete. Now, driving a gas-fueled auto was no trouble at all.
Unfortunately, as more and more people bought GM cars, more and
more people noticed a problem: When they heated up, their engines
made an alarming racket, banging and clattering as though their
metal parts were loose under the hood.
The problem, Kettering and Midgeley eventually figured out, was
that ordinary gasoline was much too explosive for spark-ignited
car engines: that is, what we now call its octane (a measure of
its resistance to detonation) was too low. To raise the fuel's
octane level and make it less prone to detonation and knocking,
Midgeley wrote later, he mixed it with almost anything he could
think of, from "melted butter and camphor to ethyl acetate and
aluminum chloride_[but] most of these had no more effect than
spitting in the Great Lakes."
He found a couple of additives that did work, however, and lead
was just one of them. Iodine worked, but producing it was much
too complicated. Ethyl alcohol also worked, and it was
cheap-however, anyone with an ordinary still could make it, which
meant that GM could not patent it or profit from it. Thus, from a
corporate point of view, lead was the best anti-knock additive
there was.
In February 1923, a Dayton filling station sold the first tankful
of leaded gasoline. A few GM engineers witnessed this big moment,
but Midgeley did not, because he was in bed with severe lead
poisoning. He recovered; however, in April 1924, lead poisoning
killed two of his unluckier colleagues, and in October, five
workers at a Standard Oil lead plant died too, after what one
reporter called "wrenching fits of violent insanity." (Almost 40
of the plant's workers suffered severe neurological symptoms like
hallucinations and seizures.)
Still, for decades auto and oil companies denied that lead posed
any health risks. Finally, in the 1970s, the Environmental
Protection Agency required that carmakers phase out
lead-compatible engines in the cars they sold in the United
States. Today, leaded gasoline is still in use in some parts of
Eastern Europe, South America and the Middle East.
73, K.O. n0kfq
N0KFQ @ N0KFQ.#SWMO.MO.USA.NA
E-mail: kohiggs@gmail.com
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