Murphy's law: possible origin

[Gerald Cohen]

   Barry Popik has done considerable research on  "Murphy's Law" in an
attempt to track down the original Murphy. Thus far no relevant
Murphy has turned up whose existence can be verified.

    So where did the expression come from?  A possible answer is given
in an unlikely source: Robert A. Wilson's _Playboy's Book of
Forbidden Words_, Chicago, Illinois: Playboy Press 1972. Page 198
contains the following item:
"PLAYING THE MURPHY--
    "A confidence game, or swindle, in which a young lady and a hotel
clerk conspire to defraud horny men. The girl pretends to be a
prostitute and lures a man to a room in the hotel, whereupon she
strips naked but demands payment before climbing into bed.  Slipping
the money into her purse, she goes into the bathroom, allegedly to
wash up and affix a diaphragm; since she is nude except for the
purse, the man has no suspicions. The bathroom, however, adjoins a
room that is empty and the purse contains a dress.  When the mark
(victim) gets wise, she is far away, and, of course, nobody in the
hotel knows anything about a nude girl running through the halls. The
expression itself, _playing the Murphy_, may come from the old
fold-up Murphy bed, which disappeared into a wall.  Among engineering
students, the Murphy factor is a term included in an equation, after
the fact, to make the answer come out right and deceive the teacher.
Murphy's Law, among engineers, holds that if anything can go wrong,
it will."

    I will remain non-committal on this etymology until I have a
chance to check it out. Still, it may offer a possibility of solving
the Murphy's Law mystery.

----Gerald Cohen