Alan French wrote:

I believe that the Amateur Scientist column in Scientific American had at
least one article on actually ruling a diffraction grating. (Just in case
anyone is really ambitious.)

I thought you were a nice guy, Alan, and here you are leading the
unsuspecting down a primrose pathway. Here's what Uncle Al Ingalls
said in the June 1952 Scientific American:

" . . The specifications are fantastic, but even more fantastic is the
ruling engine that has been contrived to do the job. This machine,
less complex in structure than a typewriter, is the most precise
mechanism ever made. It is so transcendently difficult to build and
operate that it has challenged man's mechanical genius and humbled his
pride for more than a century . . Why has this simple machine
frustrated so many able men? The dream of building a ruling engine has
haunted hundreds and ruined many. Recently a friend . . talked of long
deferred plans to quit his vocation and build an engine. "Over my dead
body!" exclaimed his wife, to whom he had once unwisely revealed that
a man might spend 10 nonproductive years curing a chronic case of
ruling engine fever the hard way . . When an Australian nurseryman
named H.J. Grayson
died after years of this acute malady . . his widow bitterly burned
all his ruling engine papers.
The central difficulty that has defeated so many efforts is the
inherent deformability of any material of which a machine may be built
.. . On the scale of ultra-ultra precision with which we must deal in
a ruling engine we may regard the machine as being made of rubber. In
effect it has just about the same problem as an intoxicated man called
upon to pass a test of sobriety: it must place the tip of its finger
(the diamond) on the tip of its nose (the groove position) within a
millionth of an inch, and it must do this with a rubber arm and body!"

I'm going to have to speak to Susan about your postings. Maybe she
can influence you to desist from these subversive suggestions.

Your friend, Howie