Thanks to SAA for the help in finding websites listing upcoming
space/astronomy events.


Some readers might be interested in lenses used in lighthouses.
I collect images of these Fresnel lenses. Three of the biggest are shown
in these images:

http://home.europa.com/
~telscope/temp/Makapuu.Light.Hyper.radiant.lens.jpg 180kb

http://home.europa.com/
~telscope/temp/Makapuu.lens.8.75ft.diam.13ft.high.1140.prisms.190 9.jpg
600kb

http://home.europa.com/~telscope/temp/hyper-
radial.Manora.Point.LH.Pakistan.-Chance.Bros.15.tons.20ft.jpg
450kb
--
=============================================
Peter Abrahams telscope.at.europa.dot.com
The history of the telescope and the binocular:
http://home.europa.com/~telscope/binotele.htm