NavList:

   

Reply

Dear Frank,

In your message Thu May 04 2006 - 21:57:26 EDT
you wrote:

>Since your instrument passed certification by not one, but two,
>recognized experts I doubt your mirrors are the problem.

I have some doubts on "certification by recognized experts",
as expressed in
my recent message on Sextant certificates
Thu May 04 2006 - 13:05:50 EDT,
Using this opportunity, I correct the addresses of
the two pictures mentioned in that message, they are
http://www.math.purdue.edu/~eremenko/cert1.jpeg
and
http://www.math.purdue.edu/~eremenko/cert2.jpeg
The reasons of my doubts are:

1) C+P certificate says "free from errors for practical use"
and Freiberger's certificate shows 13" arc error at one place.
I agree that 13" is OK for "practical use" but not for the
Lunar and star distances that I am doing.
And I guarantee that nothing has happened to the sextant
between these two certifications.

2) My multiple attempts to check the arc myself using star
distances give quite consistent results that DISAGREE with BOTH
certificates by 0'.7 to 0'.8. This is of course essential, even
for "practical use". But certainly I cannot be 100% sure
in these results because I might just be a poor observer,
or some other effect than the deformation of the arc could
explain this.

Alex.

   

Reply