And if you want to see how fast radiation cooling works, see <genehorr.home.texas.net/cooling.html>. Warning, some versions of IE distorts the GIFs so that they are not readable. Gene Horr genehorr@texas.net _______________________________________________ Astro-Photo mailing list Astro-Photo@seds.org http://seds.org/mailman/listinfo/astro-photo