Gianni and John,
A good front face mirror for the sun can be made from a scrap of
ordinary
window glass. Mark it with a glass cutter (or a carbide scribe) and make
controlled breaks along the pre-scribed lines to obtain the size you
want.
Soften the sharp edges and corners with wet or dry
John,
I am happy (though embarrassed) to report that I am now convinced
that most of the edge problems I saw in the proposal photos
were apparently artifacts. Theyseem to have been
introduced
into thePDFimages by the compression/decompression
processes.
Perhaps some spatial periodicity
I have not been following List postings very closely for some time,
but a recent attempt to catch up made me realize that much attention
has been given to shadow sharpeners re John's Kitt Peak project.
This leads me to ask:
What efforts have been made to assess the straightness and 'truth' of
Hal,
For various dialing purposes, I'veused recycled plastic jars or
bottlesas markers.
At first I would fill the milk-whitetypewith soil or sand,
screw the lids on, and
paint numerals on what would normally be the containers'
bottoms.I later took to using
clear (peanut butter) jars, soI
