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From: telecom@ucbvax.UUCP
Newsgroups: mod.telecom
Subject: Telecommunications History & Trivia
Message-ID: <8601300934.AA08968@ucbvax.berkeley.edu>
Date: Wed, 29-Jan-86 13:18:21 EST
Article-I.D.: ucbvax.8601300934.AA08968
Posted: Wed Jan 29 13:18:21 1986
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	Just today I found the real answer to a question which has piqued my
curiosity for many years: What does the `E' and `M' stand for in the term
``E&M signaling''?  No one - including people I have asked who work for the
"Bell System" - has ever been able to answer other than "the letters have no
meaning, but were arbitrary lead designations in a long-forgotten signaling
system".
	According to an AT&T Long Lines training manual from the early 1940's
(which I recently rescued from the trash), the `E' stands for ``Ear'', and the
`M' stands for ``Mouth''.  Think about it; it actually makes SENSE.
	Telecommunications history has always been an interest of mine, and
one of my favorite reference sources is a two volume set entitled: "A History
of Science and Engineering in the Bell System", which is profusely illustrated
and covers the time period of 1875 to 1925 in Volume I, and 1925 to 1975 in
Volume II.  These books were both written and published by Bell Telephone
Laboratories.  I bought my set directly from the BTL publications department
about ten years ago.  I don't know if copies are still available, but I would
highly recommend these books for anyone with similar interests.  There are also
good sections on the history of computers and military electronics.
As detailed (~ 1,900 pages total) as these books are, though, they still
couldn't answer the E&M lead question...

==>  Larry Lippman @ Recognition Research Corp., Clarence, New York        <==
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