From: "Richard Schwartz" 
To: 
Reply-To: "Richard Schwartz" 


A common fault when hogging out is that there is a center pit with
untouched edge zones.   If you measure the sagitta at the center, the
measurement is
too deep to represent the overall curve.  If you measure near the edge, it
is too shallow.   Try the following compromise:   at the 50% zone, you get
3/4 the sagitta of the overall curve; at the 71% zone, you get half the sagitta.

. . . Richard


----- Original Message -----
From: "Jeff Anderson-Lee" 
To: "Bob May" ; "atmlist"

Sent: Tuesday, March 18, 2003 9:55 AM Subject: URLS and archives [was: Re:
ATM ROC with a straight edge and drill
bits]


>
> Bob May  wrote:
> > Tony, now you need to put the metric drills and fractional drills in
there
> > and you will have a good list of the drill sizes that are available and
> that
> > can go on a webpage with the various sag-radius formulas and maybe a
table
> > of some standard mirror sizes with the sag for particular radii.
> > The chart with radius going down and mirror diameter going across with
> sag.
> > values filling the intersections?
>
> I'm at a quandary.  This list is excellent as an immediate resource for
help
> and fair as a long-term archival resource. (I often find it hard to
search.)
> Putting URLs into e-mail messages helps the immediate resource property,
but
> is potentially detrimental to the long-term archival aspect as URLs tend
to
> "decay" over time unless there is committed archival storage for their
data.
> At the same time, I feel reluctant to put large tabular data into e-mail
as
> a way to get it into the archives and the "text-only" mode of the list
makes
> it harder to archive images and non-ascii data files or programs for
> example.
>
> Is there some stable/long-term ATM web resource where we could place such
> items and then safely refere to them from this list, knowing that the
links
> in the archive would be more likely to survive?
>
> Jeff Anderson-Lee
> Sacramento, CA
>
>
>

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