On Tue, Mar 07, 2006 at 02:09:40PM -0000, Graham Bentley wrote: > > Description: Glass bulb, similar to light bulb but with > narrow end flared at bootom so it standsup. Inside, > a rotating wire device that has 4 squares of card like > material attached, like vanes. > > One one side they are black on the other they are white. > When the sun shines brightly enough, the white side reflects > the light energy and the black side absorbs it. The vanes > spin around. > > This does exist and has a name and I know there are > some very knowledgeable people on this list who will > know.
It's called a radiometer. I've seen them called other things, like a "lightmill" or a "light gauge". _______________________________________________ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"