Ruling engines for the hobbiest are no primrose path no matter how you
dice it. Their very nature makes that self-evident and anyone attempting
one would find that out straightaway. That was what Ingalls was saying.
Scientific American had a kind of elitist attitude when it came to its monthly
projects, or nonprojects as the case sometimes was. Parts availability often
fell short of suggested reality, and of course everyone had a 12" lathe and
2 ton marble slab in their basements just wating to be used! There was often
something stoggy and Limbauesque about much of this, as if these projects
were being handed down by an Angel for mortals to wrestle with and be
brought into submission by. The next month would bring an even more impossible
puzzle. Thank God the text of the magazine did not follow a
similar line of thought ....... or lack of thought.

The thought of making one's own grating today really is a bit bizzare, or a
throwback idea, not to mention the inherent problematics. Buy the $3.00
gratings the guy suggests above and save your sanity... and your finger
nails.

And once you have built the ruling machine what in hell will you do with
it then? Peel mangos?

Paul.




Howie Glatter wrote:

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