[texhax] use of " in LaTeX

[bill purvis]

Thanks for all the responses to my query. I've ended up with:
\newcommand{\inch}{\ensuremath{''}\xspace}
which seems to me to be most pleasing. I included the \ensuremath even though
I thought all my measurements (which mostly involve imperial fractions) are
in math mode, and then realised that there was one occurrence, in the title,
where it wasn't. Saves having to remember....

Many thanks to all who offered suggestions.

Bill
-- 
+---------------------------------------+
| Bill Purvis, Amateur Mathematician    |
|  email: bil at beeb.net                  |
|  http://bil.members.beeb.net          |
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