"
I can't tell you any such thing.  What meets criterion a) doesn't meet b).  Apparently no one else has anything to support the current ± language either.  Walter Nissen (talk) 2010-07-19 20:41

There is another source for Tavernor on his derivation of ""plus or minus"" 
and why he chose ""Smoot's Ear"" for his title:
http://tech.mit.edu/V127/N43/smoot.html
This is an account by Marie Y. Thibault of Tavernor's speech at MIT 
about his book, with Smoot in attendance.

Both his Preface and his speech have similar structures concerning 
Smoot's Ear and ""plus or minus"".
Both appear to be explanations of his choice of title.
Both open with ""+ 1 ear"".
It's presented by Tavernor as the historical basis, i.e., the 
historical measurement as shown by the 1987 plaque, and the 
decades of paint on the bridge.
Both derive ""plus or minus"" from ""+ 1 ear"".
Neither states that the historical measurement was ""plus or minus"". 
Thibault gives a direct quote from Tavernor 'The significance of
Smoot’s Ear is that is stands for an approximation, a “plus or
minus”'.
""Smoot's Ear"" is a component of the historical measurement,
""+ 1 ear"".
""stands for"" is clearly not an historical recounting,
but a reference to Tavernor's interpretation.
He's distinguishing the earlier ""Ear"" from his contribution,
""plus or minus"".

If ""plus or minus"" were already part of the historical record, it
wouldn't be necessary or desirable to begin with ""+ 1 ear"".

""Plus or minus"" was not part of the historical record, it was
introduced (for purposes of this discussion) by Tavernor as
his interpretation, not part of the historical record.   
Tavernor's account in the Thibault article is clearer on some of 
these points than the Preface, but both seem to achieve the same 
basic end, explaining how the ""ear"" in ""+ 1 ear"" from the
measurement on the bridge leads to the ideas in the book, beginning
with ""plus or minus"", i.e., uncertainty.

Tavernor isn't trying to say that his treatment was on the bridge,
nor measured on the bridge,
quite the contrary, that he took this human measurement, with a
component obviously intended to provoke, inter alia, the notion
of uncertainty, and related it to the whole history of
measurement and made a book of it.

It doesn't matter how many times Tavernor says
the bridge measures 364.4 Smoots plus/minus an Ear.
He could say it 300 times.
He might even say the length of the bridge is 360
Smoots plus or minus an ear.
That has its own truth.
These are only a couple of simple derivative forms 
out of a host of possible derivative forms.
From what are they derived?
Tavernor tells us.
He begins his Preface and book and speech on this subject with
the historical measurement, 364.4 smoots + 1 ear.

Tavernor's first reference citation within his book, for the 
Preface, which certainly seems to be the one he considers most
important, is to what he calls a corroborating interview 
http://www.npr.org/templates/story/story.php?storyId=5043041
That's the one I quoted earlier 
[ 2005-12-07 ]
""Now how long is the Harvard Bridge if it's measured in smoots?""
Mr. SMOOT [himself]: 
""Three hundred and sixty-four point four, plus one ear.""
It'd be pretty incongruous to argue that he found ""plus or minus""
there.
Also, he repeatedly cites WP, which at the time, didn't have
""plus or minus"".
Contrary to my initial thoughts when his Preface was being
put forward to re-write history, that he was 
not well situated to know about this, he does make it clear 
that he carefully checked into the bridge.
He is a distinguished scholar and an architect who
happens to be in a Dept. of Sociology, who wrote a book that 
seems to be a good read.

Tavernor's Preface was cited on the 
morning of New Year's Day, 2008, as support for the edit of 
Smoot to add ±, but the Preface actually refutes the 
edit by its reference to + 1 ear.
± didn't arise on the bridge; it showed up in Tavernor's
Preface.
Tavernor quotes the 1987 plaque to that effect.

If no one can say what from Tavernor's Preface seems to a) conform 
to WP:NOR and b) support the current language of the 5 
articles, then, yes, this would be an excellent time to revert to 
something only a minor copy-edit different than the language which