Date: Tue, 7 Mar 2006 09:17:43 -0500 From: David Scheidt <dscheidt@panix.com> To: Graham Bentley <gbentley@uk2.net> Cc: freebsd-questions@freebsd.org Subject: Re: Tape backup / Bizzare Device Question Message-ID: <20060307141743.GA29399@panix.com> In-Reply-To: <000901c641f0$c6e39d40$0807a8c0@admin> References: <20060307120034.063B116A420@hub.freebsd.org> <000901c641f0$c6e39d40$0807a8c0@admin>
next in thread | previous in thread | raw e-mail | index | archive | help
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".
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20060307141743.GA29399>