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Andres, you wrote:
"Frank, you have said that there are eight, who are the other two members of
navList?"

There are even more than two at this point. I'm not sure it's appropriate
for me to post their names here, so I'll leave it up to them to say they're
attending. And in any case, reservations and attendance are not the same
thing. We'll have to see how many actually make it.

NavList has 240 members signed up. Probably, half of those are dead
memberships (people who signed up for a day and discovered it wasn't about
horoscopes, people who signed up and couldn't figure out what to do next,
people who signed up to spam us and discovered that we have ways of
preventing that). Of the remainder, around half of those are "lurkers". If
you don't know that expression, it refers to people who regularly read the
content of an online discussion group but never participate. Several lurkers
are coming to Mystic this week.

And:
"I wish a detailed feedback, if it is possible, on the list in the days
following the nav weekend."

I will try. It's a ton of work already. :-)

And:
"Especially I am interested about the accurate "index correction" test using
an ordinary laser level."

This one is easy. I have described it on the list previously and also did a
rough demo in Mystic in 2006. The only difference this year is that I have
found an unused parking lot with a 300 foot range that we can probably use.
I have to buy a new laser level though.

The trick in short: in a sextant with no index error (or with the micrometer
set to the correct spot to cancel the index error), if you aim a laser down
the sight tube of your sextant at the dividing line on the horizon glass,
you get a direct beam passing through the horizon glass and a reflected beam
bouncing from the mirrors. Those beams will remain exactly parallel if the
index error is zero. So you hold up a piece of paper a meter in front of the
sextant. You mark two dots on the paper where the centers of the two beams
fall. And then you take a walk and check whether the two beams are still the
same distance apart at a greater distance. If you go about a hundred meters,
that's far enough to detect a tenth of a minute of arc deviation. If the
beams are parallel, the distance between the spots will not change. Some
laser levels are up to the task. Others have too much beam spread.

 -FER



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