Indeed he did, although I'm sure he didn't get it completely out of thin air. I was reading about Wallis' feud with Hobbes (over 'squaring the circle') when I found this snippet. Spent all those years looking at it and never even considered where it came from - how often do we do that? Not too sure about Steve's comment about linked circles though. And can any object be said to be 'at infinity'? AndrewF >Anddd.... >we have a winner!! > >Wallis first used this symbol in 1655 in "De sectionibus conicis" and again >in "Arithmetica infinitorum" in 1656. > >Bill Ellis >wb9cac@attbi.com > > >----- Original Message ----- > >From: "Steve Hodges" <shodges@wantree.com.au> >To: "List for Photo/Imaging Educators - Professionals - Students" ><photoforum@listserver.isc.rit.edu> >Sent: Sunday, September 08, 2002 8:19 AM >Subject: Re: Infinity sign on lenses > > >> I'll go with John Wallis. >> >> Steve >> >> ADavidhazy wrote: > > > > > > AndrewF posed: > > > "You've all seen the flat eight on your lens - know who 'invented' it?"
