The generally given web site:  http://hometown.aol.com/julesfran/index.html,  has gone into web site heaven.  In searching on descriptions of this test, I can find some general references, but they all seem to imply that I have read the above mentioned site.  

I'm looking for a comprehensive one stop description of the test - does anyone know of one?  

Thanks,

Gil
Ventura

Don't know of one myself.
I have looked at the test and figured out that it is basically a
double  Foucault test run imutaniously on the mirror.  One side
produces the shadow and the other side illuminates the shadow and
the joint between the two ends up being dark beecaus of the widty
of the wire and thus you see the 5-%  brightness of the zone in
question.
Hope this helps with figuring out what is going on.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net

and wasn't able to get the examples to work. There were some brackets that
didn't make it to the printed page in the original article. He helped me to
get it running OK.

I have tried to access the Way Back Machine to get the web page, but some of
the pictures don't come thru.
But all is not lost.

I do have some of the webpages saved on my computer with some screen saves
if you would like.

Virgil Johnson
Raider of the Lost Dark

I've got two programs that reference the Lateral Wire Test.  Sixtests
will process LWT measurements, and there's something in the help file
that talks about it (if I remember right):

          http://home.earthlink.net/~burrjaw/public/win6.zip  
(Win32, 2007-03-17, 372 k)

Diffract simulates, using wave optics, what the LWT would look like
on a mirror with or without surface deviations:

          http://home.earthlink.net/~burrjaw/public/diffract.zip  
(Win32, 2009-03-06, 387 k)

         -- Jim Burrows
         -- http://home.earthlink.net/~burrjaw
         -- mailto:burrjaw*******
         -- Seattle N47.4723 W122.3662 (WGS84)

FWIW: here is the "Way Back Machine's" link to the above URL...
http://web.archive.org/web/*/http://hometown.aol.com/julesfran/index.html

maybe it contains what you seek?

FWIW2: i've never been able to get all graphics and/or stored files to download
from the "Way Back Machine's" archives... depending on the site archived, you
may or may not get graphics...

That isn't the test that I was thinking about!  It appears that
this test  is moore measuring a relative distance from the center
of the mirror ala a sort of Ronchi test.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net

Replace the slitless KE w/t plastic w/t a vertical scratch (virtual wire). place the tester inside of ROC.  Align the testers lateral axis perpendicular to the OA (optical axis).  Mark the mirror w/t sharpy (or use an Evert stick) at the zones.  Move the tester laterally so as to align the shadow of the virtual wire over the marked zone and record the lateral measurement.

LWT is a moving source test (virtual wire is above the source i.e., reflected & source ray are coincident).
  
half the distance between zone pairs "y" for a parabola is:
y=h/R(s-l) where l is measured the longitudinal distance measured from ROC (negative in front & positive in back of ROC).  s=h^2/(2R).
h/R=-y/(l-s) // h is above OA y is below
(hl-sh)/R=-y
y=h/R/(s-l) Foucault: s'=Ry/h+l - use Sixtests.exe to see the glass surface plot i.e., Foucault is the derivative of the surface.